A Bioinspired Catalytic Aerobic Oxidative C–H Functionalization of Primary Aliphatic Amines: Synthesis of 1,2-Disubstituted Benzimidazoles

Science.gov (United States)

Nguyen, Khac Minh Huy; Largeron, Martine

2015-01-01

Aerobic oxidative C–H functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. PMID:26206475

Tertiary-amine-containing thermo- and pH-sensitive hydrophilic ABA triblock copolymers: effect of different tertiary amines on thermally induced sol-gel transitions.

Science.gov (United States)

Henn, Daniel M; Wright, Roger A E; Woodcock, Jeremiah W; Hu, Bin; Zhao, Bin

2014-03-11

This Article reports on the synthesis of a series of well-defined, tertiary-amine-containing ABA triblock copolymers, composed of a poly(ethylene oxide) (PEO) central block and thermo- and pH-sensitive outer blocks, and the study of the effect of different tertiary amines on thermally induced sol-gel transition temperatures (T(sol-gel)) of their 10 wt % aqueous solutions. The doubly responsive ABA triblock copolymers were prepared from a difunctional PEO macroinitiator by atom transfer radical polymerization of methoxydi(ethylene glycol) methacrylate and ethoxydi(ethylene glycol) methacrylate at a feed molar ratio of 30:70 with ∼5 mol % of either N,N-diethylaminoethyl methacrylate (DEAEMA), N,N-diisopropylaminoethyl methacrylate, or N,N-di(n-butyl)aminoethyl methacrylate. The chain lengths of thermosensitive outer blocks and the molar contents of tertiary amines were very similar for all copolymers. Using rheological measurements, we determined the pH dependences of T(sol-gel) of 10 wt % aqueous solutions of these copolymers in a phosphate buffer. The T(sol-gel) versus pH curves of all polymers exhibited a sigmoidal shape. The T(sol-gel) increased with decreasing pH; the changes were small on both high and low pH sides. At a specific pH, the T(sol-gel) decreased with increasing the hydrophobicity of the tertiary amine, and upon decreasing pH the onset pH value for the T(sol-gel) to begin to increase noticeably was lower for the more hydrophobic tertiary amine-containing copolymer. In addition, we studied the effect of different tertiary amines on the release behavior of FITC-dextran from 10 wt % micellar gels in an acidic medium at 37 and 27 °C. The release profiles for three studied hydrogels at 37 °C were essentially the same, suggesting that the release was dominated by the diffusion of FITC-dextran. At 27 °C, the release was significantly faster for the DEAEMA-containing copolymer, indicating that both diffusion and gel dissolution contributed to the

Environmentally friendly chemoselective oxidation of primary aliphatic amines by using a biomimetic electrocatalytic system.

Science.gov (United States)

Largeron, Martine; Chiaroni, Angèle; Fleury, Maurice-Bernard

2008-01-01

Environmentally friendly oxidation of primary aliphatic amines to imines has been successfully achieved, under metal-free conditions, by the use of diverse electrogenerated o-azaquinone mediators. High catalytic performance, together with high chemoselectivity, were observed with electron-poor o-azaquinone catalysts generated from 2-aminoresorcinol derivatives. Similar to copper amine oxidase enzymes, these mediators exhibited lower reactivity toward alpha-branched primary amines and no reactivity toward secondary amines. In the case of 3,4-aminophenol derivatives lacking a 2-hydroxy group, the generated o-azaquinone species failed to catalyze the oxidation of the amine to the corresponding imine. Further mechanistic considerations allowed a rationalization of the crucial role of the 2-hydroxy group in converting a catalytically inert species into a highly effective biomimetic catalyst.

Influence of nature, concentration and pH of buffer acid-base system on rate determining step of the electrochemiluminescence of Ru(bpy)32+ with tertiary aliphatic amines

International Nuclear Information System (INIS)

Pastore, Paolo; Badocco, Denis; Zanon, Francesco

2006-01-01

The electrogenerated chemiluminescence (ECL) of Ru(bpy) 3 2+ (bpy 2,2'-bipyridyl) with tertiary aliphatic amines as co-reactants, was theoretically and experimentally studied as a function of the pre-equilibria involved in the ammonium proton lost and in relation to the nature of the rate determining step. Transient potential steps were used with a 3-mm glassy carbon disk electrode or carbon fiber ultramicroelectrodes array to investigate emission behavior in a variety of aqueous solution types, containing phosphate, tartrate and phthalate acid-base systems at differing pH values. The emission of Ru(bpy) 3 2+ resulting from the reaction with n-tripropylamine (TPrA), tri-isobutylamine (TisoBuA), n-tributylamine (TBuA), methyl-di-n-propylamine (MeDPrA) and triethylamine (TEtA) in varying acid-base media was interpreted on the basis of the quoted pre-equilibria, ammonium pK a being known. The nature of the rate determining steps changes depending on pH. Above pH ∼ 5 the amine neutral radical formation is the rate determining step and, is independent of pH with rate constant close to 10 3 s -1 ; below pH ∼ 5 the rate determining step becomes the deprotonation of the ammonium ion, operated by different bases present in solution. Different amines in the same acid-base system showed analogous ECL behavior, conditioned by the chosen acid base system. A single amine in different acid-base systems showed different kinetic behaviors, due to the dissociation constants of the chosen buffers. The concentration of the acid-base system also played an important role and influenced emission intensity and shape. ECL emission were simulated by finite difference methods, implementing a previously proposed mechanism by including the relevant pre-equilibria. Simulation may also give estimates of the pK a values of the ammonium ions. An ion pair formation between R 3 N· + and the mostly charged species present in solution is hypothesized to explain the contradictory experimental

Oxidation of tertiary amines by cytochrome p450-kinetic isotope effect as a spin-state reactivity probe.

Science.gov (United States)

Li, Chunsen; Wu, Wei; Cho, Kyung-Bin; Shaik, Sason

2009-08-24

Two types of tertiary amine oxidation processes, namely, N-dealkylation and N-oxygenation, by compound I (Cpd I) of cytochrome P450 are studied theoretically using hybrid DFT calculations. All the calculations show that both N-dealkylation and N-oxygenation of trimethylamine (TMA) proceed preferentially from the low-spin (LS) state of Cpd I. Indeed, the computed kinetic isotope effects (KIEs) for the rate-controlling hydrogen abstraction step of dealkylation show that only the KIE(LS) fits the experimental datum, whereas the corresponding value for the high-spin (HS) process is much higher. These results second those published before for N,N-dimethylaniline (DMA), and as such, they further confirm the conclusion drawn then that KIEs can be a sensitive probe of spin state reactivity. The ferric-carbinolamine of TMA decomposes most likely in a non-enzymatic reaction since the Fe-O bond dissociation energy (BDE) is negative. The computational results reveal that in the reverse reaction of N-oxygenation, the N-oxide of aromatic amine can serve as a better oxygen donor than that of aliphatic amine to generate Cpd I. This capability of the N-oxo derivatives of aromatic amines to transfer oxygen to the heme, and thereby generate Cpd I, is in good accord with experimental data previously reported.

A Hydrazone-Based exo-Directing-Group Strategy for β C-H Oxidation of Aliphatic Amines.

Science.gov (United States)

Huang, Zhongxing; Wang, Chengpeng; Dong, Guangbin

2016-04-18

Described is a new hydrazone-based exo-directing group (DG) strategy developed for the functionalization of unactivated primary β C-H bonds of aliphatic amines. Conveniently synthesized from protected primary amines, the hydrazone DGs are shown to site-selectively promote the β-acetoxylation and tosyloxylation via five-membered exo-palladacycles. Amines with a wide scope of skeletons and functional groups are tolerated. Moreover, the hydrazone DG can be readily removed, and a one-pot C-H acetoxylation/DG removal protocol was also discovered. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands

Directory of Open Access Journals (Sweden)

H. Herrmann

2009-12-01

Full Text Available Monomethylamine (MA, dimethylamine (DMA and diethylamine (DEA were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0–30 pg m⁻³ for MA, 130–360 pg m⁻³ for DMA and 5–110 pg m⁻³ for DEA during the spring bloom in May 2007 and 2–520 pg m⁻³ for MA, 100–1400 pg m⁻³ for DMA and 90–760 pg m⁻³ for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14–0.42 μm indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC content ranged from 0.2–2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N–1.5% N in the sum of nitrate, ammonium and amines. This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment.

Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

Directory of Open Access Journals (Sweden)

P. J. Silva

2009-03-01

Full Text Available Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<1% for all amines tested as detected by an aerosol mass spectrometer (AMS. We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

Catalyst Deactivation Reactions : The Role of Tertiary Amines Revisited

NARCIS (Netherlands)

Novarino, Elena; Rios, Itzel Guerrero; van der Veer, Siebe; Meetsma, Auke; Hessen, Bart; Bouwkamp, Marco W.

2011-01-01

Decamethylzirconocene cation [Cp*2ZrMe](+) (2) decomposes in bromobenzene-d(5) solution to generate sigma-aryl species [Cp*Zr-2(2-C6H4Br-kappa Br,C)][B(C6F5)(4)] (3). This a-bond metathesis reaction is catalyzed by tertiary amines via a two-step mechanism, in which the amine acts as a proton relay.

Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

International Nuclear Information System (INIS)

Moyer, B.A.; McDowell, W.J.

1981-01-01

The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used

The ozonolysis of primary aliphatic amines in fine particles

Science.gov (United States)

Zahardis, J.; Geddes, S.; Petrucci, G. A.

2008-02-01

The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3- (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents

International Nuclear Information System (INIS)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

2014-01-01

Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO 2 . • Tertiary alkanolamines chemically and irreversibly absorb SO 2 through OH group. • SO 2 absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO 2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO 2 through oxygen atom, forming an ionic compound with a covalently bound -OSO 2 − group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO 2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities

A study of structure–activity relationships of commercial tertiary amines for post-combustion CO_2 capture

International Nuclear Information System (INIS)

Xiao, Min; Liu, Helei; Idem, Raphael; Tontiwachwuthikul, Paitoon; Liang, Zhiwu

2016-01-01

Highlights: • Ethyl group is beneficial for tertiary amines of CO_2 absorption. • The existence of side carbon chain may promote the activity of tertiary amine. • Hydroxyl group reduces the equilibrium CO_2 solubility, k_2 and pKa. • Heterocyclic structure decrease the equilibrium CO_2 solubility, k_2 and pKa. • Hydroxyl group results in higher CO_2 absorption heat. - Abstract: This work examined the relationship between the structure of various commercial tertiary amines and their activity in CO_2 absorption/desorption in terms of rate of CO_2 absorption, equilibrium CO_2 loading, pKa and heat of CO_2 absorption in order to establish possible guidelines for selection of tertiary amine components for amine blends. Results show that any electron donating group linked directly to the nitrogen atom increases their reactivity with CO_2. In addition, the presence of steric hindrance effect and good water solubility also show enhancements in activity. In contrast, the existence of a hydroxyl group leads to a decrease in all the activity of the tertiary amine. The heat of CO_2 absorption of tertiary amines, which is closely related to the regeneration energy, can be reduced by decreasing the number of hydroxyethyl groups or by positing the hydroxyl group at the proper carbon relative to the nitrogen atom.

The ozonolysis of primary aliphatic amines in fine particles

Directory of Open Access Journals (Sweden)

J. Zahardis

2008-02-01

Full Text Available The oxidative processing by ozone of the particulate amines octadecylamine (ODA and hexadecylamine (HDA is reported. Ozonolysis of these amines resulted in strong NO₂^– and NO₃^– ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO₃^– (HNO₃. For ozonized mixed particles containing ODA or HDA + oleic acid (OL, with p_O3≥3×10^–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines and stabilized Criegee intermediates (SCI or secondary ozonides (for amides from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10⁻³ atm for 17 s. This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO₂, NO₃, formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

Amperometric detection and electrochemical oxidation of aliphatic amines and ammonia on silver-lead oxide thin-film electrodes

Energy Technology Data Exchange (ETDEWEB)

Ge, Jisheng [Iowa State Univ., Ames, IA (United States)

1996-01-08

This thesis comprises three parts: Electrocatalysis of anodic oxygen-transfer reactions: aliphatic amines at mixed Ag-Pb oxide thin-film electrodes; oxidation of ammonia at anodized Ag-Pb eutectic alloy electrodes; and temperature effects on oxidation of ethylamine, alanine, and aquated ammonia.

Practical Synthesis of Amides via Copper/ABNO-Catalyzed Aerobic Oxidative Coupling of Alcohols and Amines.

Science.gov (United States)

Zultanski, Susan L; Zhao, Jingyi; Stahl, Shannon S

2016-05-25

A modular Cu/ABNO catalyst system has been identified that enables efficient aerobic oxidative coupling of alcohols and amines to amides. All four permutations of benzylic/aliphatic alcohols and primary/secondary amines are viable in this reaction, enabling broad access to secondary and tertiary amides. The reactions exhibit excellent functional group compatibility and are complete within 30 min-3 h at rt. All components of the catalyst system are commercially available.

A bioinspired catalytic aerobic oxidative C-H functionalization of primary aliphatic amines: synthesis of 1,2-disubstituted benzimidazoles.

Science.gov (United States)

Nguyen, Khac Minh Huy; Largeron, Martine

2015-09-01

Aerobic oxidative CH functionalization of primary aliphatic amines has been accomplished with a biomimetic cooperative catalytic system to furnish 1,2-disubstituted benzimidazoles that play an important role as drug discovery targets. This one-pot atom-economical multistep process, which proceeds under mild conditions, with ambient air and equimolar amounts of each coupling partner, constitutes a convenient environmentally friendly strategy to functionalize non-activated aliphatic amines that remain challenging substrates for non-enzymatic catalytic aerobic systems. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of Creative Commons Attribution NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Characterization of molybdenum interfacial crud in a uranium mill that employs tertiary-amine solvent extraction

International Nuclear Information System (INIS)

Moyer, B.; McDowell, W.J.

1983-01-01

In the present work, samples of a molybdenum-caused green gummy interfacial crud from an operating western US uranium mill have been physically and chemically examined. Formaton of cruds of this description has been a long-standing problem in the use of tertiary amine solvent extraction for the recovery of uranium from low-grade ores (Amex Process). The crud is essentially an organic-continuous dispersion containing about 10 wt % aqueous droplets and about 37 wt % greenish-yellow crystalline solids suspended in kerosene-amine process solvent. The greenish-yellow crystals were found to be a previously unknown double salt of tertiary amine molybdophosphate with three tertiary amine chlorides having the empirical formula (R 3 NH) 3 [PMo 12 O 40 ].3(R 3 NH)Cl. To confirm the identification of the compound, a pure trioctylamine (TOA) analog was synthesized. In laboratory extraction experiments, it was demonstrated that organic-soluble amine molydophosphate forms slowly upon contact of TOA solvent with dilute sulfuric acid solutions containing low concentrations of molybdate and phosphate. If the organic solutions of amine molybdophosphate were then contacted with aqueous NaCl solutions, a greenish-yellow precipitate of (TOAH) 3 [PMo 12 O 40 ].3(TOAH)Cl formed at the interface. The proposed mechanism for the formation of the crud under process conditions involves build up of molybdenum in the solvent, followed by reaction with extracted phosphate to give dissolved amine molybdophosphate. The amine molybdophosphate then co-crystallizes with amine chloride, formed during the stripping cycle, to give the insoluble double salt, which precipitates as a layer of small particles at the interface. The proposed solution to the problem is the use of branched-chain, instead of straight-chain, tertiary amine extractants under the expectation that branching would increase the solubility of the double salt. 2 figures, 5 tables

Influence of nature, concentration and pH of buffer acid-base system on rate determining step of the electrochemiluminescence of Ru(bpy){sub 3} {sup 2+} with tertiary aliphatic amines

Energy Technology Data Exchange (ETDEWEB)

Pastore, Paolo [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy)]. E-mail: paolo.pastore@unipd.it; Badocco, Denis [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy); Zanon, Francesco [Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova (Italy)

2006-07-28

The electrogenerated chemiluminescence (ECL) of Ru(bpy){sub 3} {sup 2+} (bpy 2,2'-bipyridyl) with tertiary aliphatic amines as co-reactants, was theoretically and experimentally studied as a function of the pre-equilibria involved in the ammonium proton lost and in relation to the nature of the rate determining step. Transient potential steps were used with a 3-mm glassy carbon disk electrode or carbon fiber ultramicroelectrodes array to investigate emission behavior in a variety of aqueous solution types, containing phosphate, tartrate and phthalate acid-base systems at differing pH values. The emission of Ru(bpy){sub 3} {sup 2+} resulting from the reaction with n-tripropylamine (TPrA), tri-isobutylamine (TisoBuA), n-tributylamine (TBuA), methyl-di-n-propylamine (MeDPrA) and triethylamine (TEtA) in varying acid-base media was interpreted on the basis of the quoted pre-equilibria, ammonium pK {sub a} being known. The nature of the rate determining steps changes depending on pH. Above pH {approx} 5 the amine neutral radical formation is the rate determining step and, is independent of pH with rate constant close to 10{sup 3} s{sup -1}; below pH {approx} 5 the rate determining step becomes the deprotonation of the ammonium ion, operated by different bases present in solution. Different amines in the same acid-base system showed analogous ECL behavior, conditioned by the chosen acid base system. A single amine in different acid-base systems showed different kinetic behaviors, due to the dissociation constants of the chosen buffers. The concentration of the acid-base system also played an important role and influenced emission intensity and shape. ECL emission were simulated by finite difference methods, implementing a previously proposed mechanism by including the relevant pre-equilibria. Simulation may also give estimates of the pK {sub a} values of the ammonium ions. An ion pair formation between R{sub 3}N{center_dot} {sup +} and the mostly charged species

Nitrile-functionalized tertiary amines as highly efficient and reversible SO{sub 2} absorbents

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Hyunjoo [Clean Energy Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Hoon Sik, E-mail: khs2004@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Je Seung, E-mail: leejs70@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

2014-01-15

Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO{sub 2}. • Tertiary alkanolamines chemically and irreversibly absorb SO{sub 2} through OH group. • SO{sub 2} absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO{sub 2} absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO{sub 2} through oxygen atom, forming an ionic compound with a covalently bound -OSO{sub 2}{sup −} group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO{sub 2} through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities.

Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

Science.gov (United States)

Malloy, Q. G. J.; Qi, Li; Warren, B.; Cocker, D. R., III; Erupe, M. E.; Silva, P. J.

2009-03-01

Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine) are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (tested) as detected by an aerosol mass spectrometer (AMS). We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

EFSA ; Scientific Opinion on Flavouring Group Evaluation 94, Revision 1 (FGE.94Rev1): Consideration of aliphatic amines and amides evaluated in an addendum to the group of aliphatic and aromatic amines and amides evaluated by the JECFA (68th meeting)

DEFF Research Database (Denmark)

Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present consideration concerns a group of 12 aliphatic amines and amides evaluated by the JECFA at the 68th meeting in 2007. This revision of the consideration is made due to additional toxicity data available for two...

The ozonolysis of primary aliphatic amines in single and multicomponent fine particles

Science.gov (United States)

Zahardis, J.; Geddes, S.; Petrucci, G. A.

2007-10-01

The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2- and NO3- ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitro alkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3-(HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10-7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides was shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10-3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g. NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.

(E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.

Science.gov (United States)

Shi, Renyi; Zhang, Hua; Lu, Lijun; Gan, Pei; Sha, Yuchen; Zhang, Heng; Liu, Qiang; Beller, Matthias; Lei, Aiwen

2015-02-21

A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO.

Method for the production of primary amines

NARCIS (Netherlands)

Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

2014-01-01

The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

Development of four-component synthesis of tetra- and pentasubstituted polyfunctional dihydropyrroles: free permutation and combination of aromatic and aliphatic amines.

Science.gov (United States)

Lv, Longyun; Zheng, Sichao; Cai, Xiaotie; Chen, Zhipeng; Zhu, Qiuhua; Liu, Shuwen

2013-04-08

We previously reported the novel efficient proton/heat-promoted four-component reactions (4CRs) of but-2-ynedioates, two same/different primary amines, and aldehydes for the synthesis of tetra- and pentasubstituted polyfunctional dihydropyrroles. If aromatic and aliphatic amines were used as reagents, four different series of products should be obtained via the permutation and combination of aromatic and aliphatic primary amines. However, only three/two rather four different series of tetra-/pentasubstisuted dihydropyrroles could be prepared via the proton/heat-promoted 4CRs. Herein, Cu(OAc)2·H2O, a Lewis acid being stable in air and water, was found to be an efficient catalyst for the 4CR synthesis of all the four different series of tetra-/pentasubstisuted dihydropyrroles. The copper-catalyzed 4CR could produce target products at room temperature in good to excellent yields. Interestingly, benzaldehyde, in addition to being used as a useful reactant for the synthesis of pentasubstituted dihydropyrroles, was found to be an excellent additive for preventing the oxidation of aromatic amines with copper(II) and ensuring the sooth conduct of the 4CRs for the synthesis of tetrasubstituted dihydropyrroles with aryl R(3). In addition, salicylic acid was found to be needed to increase the activities and yields of the copper-catalyzed 4CRs for the synthesis of petasubstituted diyhydropyrroles. On the basis of experimental results, the enamination/amidation/intramolecular cyclization mechanism was proposed and amidation is expected to be the rate-limited step in the copper-catalyzed 4CRs.

Nucleophilic addition of amines to the activated ethylene bond in non-aqueous media

International Nuclear Information System (INIS)

Perepichka, Igor F.; Popov, Anatolii F.

1995-01-01

The kinetics of addition of a number of primary and secondary aliphatic amines to trans-(2-furyl) nitro ethylene (1) has been studied in solvents of various polarities (from acetonitrile, ε 37.5, to heptane, ε 1.89). It has been shown that the reaction is catalysed both by the amine reagent and by tertiary amines. On the basis of analyzing the observed kinetic regularities a stepwise reaction mechanism has been proposed which involves formation of zwitterionic intermediate (3) at the first equilibrium step (k 1 , K 1 ) which is then converted into the reaction product by means of proton transfer in parallel routes, the non-catalytic one (k 2 ) and that catalysed by the initial (K 3 ) or tertiary (K 4 ) amine. The observed high values of the deuterium isotope effects in the reaction (K H /K D ∼ 2.3 - 8.9) confirm that proton transfer occurs in the rate-limiting step of the reaction (primary kinetic isotope effect). The third order by amine kinetic route is observed in low polar media which is due to participation of amine dimers (R 2 NH HNR 2 ) in the reaction. The observed kinetic regularities are compared with those for the nucleophilic aromatic substitution reactions in low-polar media, and the conclusion has been made that the reaction route of the third order by amine proceeds as reversible nucleophilic attack by amine dimer and following base-catalysed transformation of the intermediate into the product. (author)

Equilibrium and Transport Properties of Primary, Secondary and Tertiary Amines by Molecular Simulation

International Nuclear Information System (INIS)

Orozco, Gustavo A.; Nieto-Draghi, Carlos; Lachet, Veronique; Mackie, Allan D.

2014-01-01

Using molecular simulation techniques such as Monte Carlo (MC) and molecular dynamics (MD), we present several simulation results of thermodynamic and transport properties for primary, secondary and tertiary amines. These calculations are based on a recently proposed force field for amines that follows the Anisotropic United Atom approach (AUA). Different amine molecules have been studied, including n-Butylamine, di-n-Butylamine, tri-n-Butylamine and 1,4-Butanediamine for primary, secondary, tertiary and multi-functional amines respectively. For the transport properties, we have calculated the viscosity coefficients as a function of temperature using the isothermal-isobaric (NPT) ensemble. In the case of the pure components, we have investigated different thermodynamic properties using NVT Gibbs ensemble simulations such as liquid-vapor phase equilibrium diagrams, vaporization enthalpies, vapor pressures, normal boiling points, critical temperatures and critical densities. We have also calculated the excess enthalpies for water-n-Butylamine and n-heptane-n-Butylamine mixtures using Monte Carlo simulations in the NPT ensemble. In addition, we present the calculation of liquid-vapor surface tensions of n-Butylamine using a two-phase NVT simulation as well as the radial distribution functions. Finally, we have investigated the physical Henry constants of nitrous oxide (N 2 O) and nitrogen (N 2 ) in an aqueous solutions of n-Butylamine. In general, we found a good agreement between the available experimental information and our simulation results for all the studied properties, ratifying the predictive capability of the AUA force field for amines. (authors)

Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

Science.gov (United States)

Gündüz, T; Kiliç, E; Cakirer, O

1996-05-01

Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

Homologation of methanol catalyzed by transition metal complexes in the presence of tertiary amines

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Masato; Ogata, Ikuei

1987-12-18

This paper describes the homologation of methanol by transition metal carbonyl catalysts in the presence of tertiary amines. Methanol was reacted with amine using a catalyst at 180/sup 0/C under 100 atm in the atmosphere of CO and H/sub 2/ mixed at the ratio of 4 in an autoclave. The reaction activities and selectivities of ethanol using iron carbonyl and Co carbonyl catalysts are superior. Only the iron catalyst was used hereafter because phosphine is required for the latter catalyst. N-methyl- piperidine, a cyclic amine, is superior to the other amines. The selectivity of ethanol is higher under higher partial pressure of H/sub 2/ and lower partial pressure of CO. The conversion rate is optimum at 180/sup 0/ and it goes down with increasing the temperature from it. Since the selectivity is markedly decreased with increasing amine, the reaction activity must be balanced with the amount of amine. The presence of solvent affects it. (3 figs, 6 tabs, 15 refs)

Probing the Compound I-like reactivity of a bare high-valent oxo iron porphyrin complex: the oxidation of tertiary amines.

Science.gov (United States)

Chiavarino, Barbara; Cipollini, Romano; Crestoni, Maria Elisa; Fornarini, Simonetta; Lanucara, Francesco; Lapi, Andrea

2008-03-12

The mechanisms of oxidative N-dealkylation of amines by heme enzymes including peroxidases and cytochromes P450 and by functional models for the active Compound I species have long been studied. A debated issue has concerned in particular the character of the primary step initiating the oxidation sequence, either a hydrogen atom transfer (HAT) or an electron transfer (ET) event, facing problems such as the possible contribution of multiple oxidants and complex environmental effects. In the present study, an oxo iron(IV) porphyrin radical cation intermediate 1, [(TPFPP)*+ Fe(IV)=O]+ (TPFPP = meso-tetrakis (pentafluorophenyl)porphinato dianion), functional model of Compound I, has been produced as a bare species. The gas-phase reaction with amines (A) studied by ESI-FT-ICR mass spectrometry has revealed for the first time the elementary steps and the ionic intermediates involved in the oxidative activation. Ionic products are formed involving ET (A*+, the amine radical cation), formal hydride transfer (HT) from the amine ([A(-H)]+, an iminium ion), and oxygen atom transfer (OAT) to the amine (A(O), likely a carbinolamine product), whereas an ionic product involving a net initial HAT event is never observed. The reaction appears to be initiated by an ET event for the majority of the tested amines which included tertiary aliphatic and aromatic amines as well as a cyclic and a secondary amine. For a series of N,N-dimethylanilines the reaction efficiency for the ET activated pathways was found to correlate with the ionization energy of the amine. A stepwise pathway accounts for the C-H bond activation resulting in the formal HT product, namely a primary ET process forming A*+, which is deprotonated at the alpha-C-H bond forming an N-methyl-N-arylaminomethyl radical, A(-H)*, readily oxidized to the iminium ion, [A(-H)]+. The kinetic isotope effect (KIE) for proton transfer (PT) increases as the acidity of the amine radical cation increases and the PT reaction to the base

Concise Redox Deracemization of Secondary and Tertiary Amines with a Tetrahydroisoquinoline Core via a Nonenzymatic Process.

Science.gov (United States)

Ji, Yue; Shi, Lei; Chen, Mu-Wang; Feng, Guang-Shou; Zhou, Yong-Gui

2015-08-26

A concise deracemization of racemic secondary and tertiary amines with a tetrahydroisoquinoline core has been successfully realized by orchestrating a redox process consisted of N-bromosuccinimide oxidation and iridum-catalyzed asymmetric hydrogenation. This compatible redox combination enables one-pot, single-operation deracemization to generate chiral 1-substituted 1,2,3,4-tetrahydroisoquinolines with up to 98% ee in 93% yield, offering a simple and scalable synthetic technique for chiral amines directly from racemic starting materials.

Extraction of some acids using aliphatic amines

International Nuclear Information System (INIS)

Matutano, L.

1964-06-01

Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [fr

Effect of donor orientation on ultrafast intermolecular electron transfer in coumarin-amine systems

International Nuclear Information System (INIS)

Singh, P. K.; Nath, S.; Bhasikuttan, A. C.; Kumbhakar, M.; Mohanty, J.; Sarkar, S. K.; Mukherjee, T.; Pal, H.

2008-01-01

Effect of donor amine orientation on nondiffusive ultrafast intermolecular electron transfer (ET) reactions in coumarin-amine systems has been investigated using femtosecond fluorescence upconversion measurements. Intermolecular ET from different aromatic and aliphatic amines used as donor solvents to the excited coumarin-151 (C151) acceptor occurs with ultrafast rates such that the shortest fluorescence lifetime component (τ 1 ) is the measure of the fastest ET rate (τ 1 =τ ET fast =(k ET fast ) -1 ), assigned to the C151-amine contact pairs in which amine donors are properly oriented with respect to C151 to maximize the acceptor-donor electronic coupling (V el ). It is interestingly observed that as the amine solvents are diluted by suitable diluents (either keeping solvent dielectric constant similar or with increasing dielectric constant), the τ 1 remains almost in the similar range as long as the amine dilution does not cross a certain critical limit, which in terms of the amine mole fraction (x A ) is found to be ∼0.4 for aromatic amines and ∼0.8 for aliphatic amines. Beyond these dilutions in the two respective cases of the amine systems, the τ 1 values are seen to increase very sharply. The large difference in the critical x A values involving aromatic and aliphatic amine donors has been rationalized in terms of the largely different orientational restrictions for the ET reactions as imposed by the aliphatic (n-type) and aromatic (π-type) nature of the amine donors [A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008)]. Since the highest occupied molecular orbital (HOMO) of the n-type aliphatic amines is mostly centralized at the amino nitrogen, only some specific orientations of these amines with respect to the close-contact acceptor dye [also of π-character; A. K. Satpati et al., J. Mol. Struct. 878, 84 (2008) and E. W. Castner et al., J. Phys. Chem. A 104, 2869 (2000)] can give suitable V el and thus ultrafast ET reaction. In contrary, the

Effect of tertiary amines on the synthesis and photovoltaic properties of TiO2 nanoparticles in dye sensitized solar cells

International Nuclear Information System (INIS)

Mir, Noshin; Salavati-Niasari, Masoud

2013-01-01

Highlights: • TiO 2 nanoparticles were synthesized via a two-step sol–gel method. • Two tertiary amines were selected as complexing agents. • Size control was achieved by selection of long chained amine. • The total conversion efficiency of 5.04% was reported as the best result. -- Abstract: Two different amines as complexing agents were used in a two-step sol–gel method to prepare TiO 2 nanoparticles. The effect of amines on the size of the TiO 2 nanocrystals and its influence on the performance of corresponding dye-sensitized solar cell (DSSC) were investigated. It is shown that using a tertiary long chained monoamine as a complexing agent is beneficial in two ways; one is producing the particles with smaller size and the other is slightly sticking the particles in order to have a film with higher reflectivity which both is beneficial to photovoltaic performance. The obtained products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra, and ultraviolet-visible (UV–vis) spectroscopy. The overall conversion efficiency of the long-chain-based DSSC (5.04%) appeared to be 45% higher than that obtained for the tertiary short-chain diamine

Assessment of the combined approach of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines using bupivacaine as a model drug

DEFF Research Database (Denmark)

Nielsen, Anders Bach; Frydenvang, Karla Andrea; Liljefors, Tommy

2005-01-01

as their iodide salts. Chloride, mesylate, formate, acetate, glycolate, and tosylate salts were obtained by anion exchange of the N-methyl-bupivacaine derivative. N-Alkylation and salt formation afforded quaternary ammonium salts possessing pH-independent aqueous solubilities far exceeding that of the parent......Quaternary prodrug types of poorly water-soluble tertiary amines have been shown to exhibit significantly enhanced solubilities as compared to the parent amine. In the present study the combined effect of N-alkylation and salt formation to enhance aqueous solubility of tertiary amines have been...

Peptidyl prolyl isomerase Pin1-inhibitory activity of D-glutamic and D-aspartic acid derivatives bearing a cyclic aliphatic amine moiety.

Science.gov (United States)

Nakagawa, Hidehiko; Seike, Suguru; Sugimoto, Masatoshi; Ieda, Naoya; Kawaguchi, Mitsuyasu; Suzuki, Takayoshi; Miyata, Naoki

2015-12-01

Pin1 is a peptidyl prolyl isomerase that specifically catalyzes cis-trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

DEFF Research Database (Denmark)

Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.

2004-01-01

Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formatio...

Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae.

Science.gov (United States)

Matzel, Philipp; Krautschick, Lukas; Höhne, Matthias

2017-10-18

Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C 4 -C 8 ) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94-96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

International Nuclear Information System (INIS)

Alsabagh, A.M.; Migahed, M.A.; Awad, Hayam S.

2006-01-01

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV (∼96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

Energy Technology Data Exchange (ETDEWEB)

Alsabagh, A.M. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt); Migahed, M.A. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt)]. E-mail: mohamedatiyya707@hotmail.com; Awad, Hayam S. [Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, Asmaa Fahmi Street, Helliopolis, Cairo (Egypt)

2006-04-15

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV ({approx}96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.

Astramol polypropyleneimine dendrimers as Norrish Type II amine synergists

NARCIS (Netherlands)

Jansen, J.F.G.A.; Dias, A.A.; Hartwig, H.; Janssen, R.A.J.

2000-01-01

UV-curable coatings for various applications . In most of these applications they serve a dual role ie as initiator and as oxygen scavenger. Dimethylethanolamine is one of the more frequently employed aliphatic amines. However, this amine is a highly volatile . AstramolTM polypropyleneimine

Thermodynamic study of (heptane + amine) mixtures. III: Excess and partial molar volumes in mixtures with secondary, tertiary, and cyclic amines at 298.15 K

International Nuclear Information System (INIS)

Lepori, Luciano; Gianni, Paolo; Spanedda, Andrea; Matteoli, Enrico

2011-01-01

Graphical abstract: Highlights: → Excess volumes of (sec., tert., or cyclic amines + heptane) mixtures. → Excess volumes are positive for small size amines and decrease as the size increases. → Group contributions to predict the partial molar volumes of amines in heptane. → The void volume is larger for sec. and tert. than for linear amines in heptane. → The void volume is much smaller for cyclic than for linear amines in heptane. - Abstract: Excess molar volumes V E at 298.15 K were determined by means of a vibrating tube densimeter for binary mixtures of {heptane + open chain secondary (diethyl to dibutyl) and tertiary (triethyl to tripentyl) amines} as well as for cyclic imines (C 2 , C 3 , C 4 , C 6 , and C 7 ) and primary cycloalkylamines (C 5 , C 6 , C 7 , and C 12 ). The V E values were found positive for mixtures involving small size amines, with V E decreasing as the size increases. Negative V E 's were found for tributyl- and tripentylamine, heptamethylenimine, and cyclododecylamine. Mixtures of heptane with cycloheptylamine showed an s-shaped curve. Partial molar volumes V 0 of amines at infinite dilution in heptane were obtained from V E and compared with V 0 of hydrocarbons and other classes of organic compounds taken from literature. An additivity scheme, based on the intrinsic volume approach, was applied to estimate group (CH 3 , CH 2 , CH, C, NH 2 , NH, N, OH, O, CO, and COO) contributions to V 0 . These contributions, the effect of cyclization on V 0 , and the limiting slope of the apparent excess molar volumes were discussed in terms of solute-solvent and solute-solute interactions.

Extraction of some acids using aliphatic amines; Extraction de quelques acides par des amines aliphatiques

Energy Technology Data Exchange (ETDEWEB)

Matutano, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-01

Hydrochloric, nitric, sulphuric, perchloric, phosphoric, acetic and formic acids in aqueous solution (0.05 to 10 M) are extracted by amberlite LA2 and trilaurylamine in solution, 5 per cent by volume, in kerosene and xylene respectively. The extraction process consists of: neutralization of the amine salt; a 'molecular extraction', i.e. an extraction using an excess of acid with respect to the stoichiometry of the amine salt. According to the behaviour of the acid during the extraction, three groups may be distinguished: completely dissociated acids, carboxylic acids, phosphoric acid. This classification is also valid for the extraction of the water which occurs simultaneously with that of the acid. An extraction mechanism is put forward for formic acid and the formation constant of its amine salt is calculated. (author) [French] Les acides chlorhydrique, nitrique, sulfurique, perchlorique, phosphorique, acetique et formique, en solution aqueuse - 0,05 a 10 M - sont extraits par l'amberlite LA2 et la trilaurylamine en solution, a 5 pour cent en volume, dans le kerosene et le xylene respectivement. L'extraction comprend: une neutralisation de l'amine par l'acide avec formation d'un sel d'amine; une 'extraction moleculaire', c'est-a-dire une extraction d'acide en exces par rapport a la stoechiometrie du sel d'amine. Suivant le comportement des acides au cours de l'extraction nous distinguons trois groupes: acides entierement dissocies, acides carboxyliques, acide phosphorique. Cette classification est egalement valable pour l'extraction de l'eau qui est simultanee a celle de l'acide. Un mecanisme d'extraction pour l'acide formique est propose et nous calculons la constante de formation de son sel d'amine. (auteur)

Inhibition of Tetrahymena pyriformis growth by Aliphatic Alcohols ...

African Journals Online (AJOL)

A Quantitative Structure- Activity Relationship (QSAR) study was undertaken to evaluate the relative toxicity of a mixed series of 21 (linear and branched-chain) alcohols and 9 normal aliphatic amines in term of the 50% inhibitory growth concentration (IGC50) of Tetrahymena pyriformis. The applied simple linear regression ...

Metal-Free Conversion of Carboxamides to Ureas Using Tertiary Amines and Iodosylmesitylene

Energy Technology Data Exchange (ETDEWEB)

Han, Hoon; Chang, Suk Bok [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2010-03-15

A new synthetic route has been developed for the preparation of ureas from the reaction of carboxamides with tertiary amines with the use of iodosylmesitylene as a stoichiometric oxidant. Although the reaction proceeds under the mild conditions to afford urea products in moderate yields, further optimization studies are required to improve the reaction efficiency and regioselectivity in the dealkylative pathway. Ureas are recognized as an important synthetic building unit, finding a wide range of applications in the preparation of agrochemicals, petrochemicals, and pharmaceuticals. In addition, hydrogen bond-mediated communication between ureas and certain types of compounds is an important structural motif in asymmetric catalysis, molecular recognition, and crystal engineering. Although numerous procedures have been developed for the urea synthesis, the most commonly employed strategy involves the reaction of amine precursors with phosgene, or its surrogates, isocyanates, or carbamates. Whereas these traditional methods are operative under conventional reaction conditions, they often lead to incomplete conversion. Additional drawback of these protocols is that unsymmetric ureas are difficult to prepare in many cases.

Tailoring Enzyme-Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress.

Science.gov (United States)

Liu, Ching-Ping; Wu, Te-Haw; Lin, Yu-Lung; Liu, Chia-Yeh; Wang, Sabrina; Lin, Shu-Yi

2016-08-01

The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase-like activity can decompose hydrogen peroxide (H2 O2 ) to produce highly toxic hydroxyl radicals (•OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating-mediated enzyme-like activities. Herein, it is reported for the first time that amine-terminated PAMAM dendrimer-entrapped gold nanoclusters (AuNCs-NH2 ) unexpectedly lose their peroxidase-like activity while still retaining their catalase-like activity in physiological conditions. Surprisingly, the methylated form of AuNCs-NH2 (i.e., MAuNCs-N(+) R3 , where R = H or CH3 ) results in a dramatic recovery of the intrinsic peroxidase-like activity while blocking most primary and tertiary amines (1°- and 3°-amines) of dendrimers to form quaternary ammonium ions (4°-amines). However, the hidden peroxidase-like activity is also found in hydroxyl-terminated dendrimer-encapsulated AuNCs (AuNCs-OH, inside backbone with 3°-amines), indicating that 3°-amines are dominant in mediating the peroxidase-like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°-amines on the surface of dendrimer-encapsulated AuNCs provides sufficient suppression of the critical mediator •OH for the peroxidase-like activity. Finally, it is demonstrated that AuNCs-NH2 with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical modification of carbon powders with aminophenyl and aryl-aliphatic amine groups by reduction of in situ generated diazonium cations: Applicability of the grafted powder towards CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Aurelie Grondein; Daniel Belanger [Universite du Quebec a Montreal, Montreal, PQ (Canada). Departement de Chimie

2011-08-15

Aminophenyl, p-aminobenzyl and p-aminoethylphenyl groups were grafted at the surface of carbon Vulcan XC72R by spontaneous reduction of the in situ generated diazonium cations from the corresponding amine. X-ray photoelectron spectroscopy and elemental analysis confirmed an amine loading of about 1 mmol/g. The grafting of amine functionalities leads to a decrease of specific surface area from 223 to about 110 m{sup 2}/g with a drastic loss of microporosity. Acid-base properties of the surface are also affected by the modification. Aminophenyl grafted groups make the surface more acidic while aryl-aliphatic amines groups tends to render it more basic. The grafted layer shows in each case a good thermal stability up to 250{sup o}C. The affinity of the modified powder towards CO{sub 2} and N{sub 2} has been evaluated by thermal swing adsorption. The maximum adsorption capacity of CO{sub 2} of modified carbons is lower than the unmodified carbon but the presence of the amine functionalities involves a better selectivity of the material towards CO{sub 2} adsorption in comparison of N{sub 2} adsorption. 53 refs., 9 figs., 3 tabs.

Catalyst- and Reagent-free Electrochemical Azole C-H Amination.

Science.gov (United States)

Qiu, Youai; Struwe, Julia; Meyer, Tjark H; Oliveira, Joao Carlos Agostinho Carlos Agostinho; Ackermann, Lutz

2018-06-14

Catalyst-, and chemical oxidant-free electrochemical azole C-H aminations were accomplished via cross-dehydrogenative C-H/N-H functionalization. The catalyst-free electrochemical C-H amination proved feasible on azoles with high levels of efficacy and selectivity, avoiding the use of stoichiometric oxidants under ambient conditions. Likewise, the C(sp3)-H nitrogenation proved viable under otherwise identical conditions. The dehydrogenative C-H amination featured ample scope, including cyclic and acyclic aliphatic amines as well as anilines, and employed sustainable electricity as the sole oxidant. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

Science.gov (United States)

Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

2016-01-19

Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

A microanalytical method for ammonium and short-chain primary aliphatic amines using precolumn derivatization and capillary liquid chromatography.

Science.gov (United States)

Moliner-Martínez, Y; Herráez-Hernández, R; Campíns-Falcó, P

2007-09-14

A new microscale method is presented for the determination of ammonium and primary short-chain aliphatic amines (methylamine, ethylamine, propylamine, n-butylamine and n-pentylamine) in water. The assay uses precolumn derivatization with the reagent o-phthaldialdehyde (OPA) in combination with the thiol N-acetyl-L-cysteine (NAC), and capillary liquid chromatography with UV detection at 330 nm. The described method is very simple and rapid as no preconcentration of the analytes is necessary, and the volume of sample required is only 0.1 mL. Under the proposed conditions good linearity has been obtained up to a concentration of the analytes of 10.0 mgL(-1), the limits of detection being of 8-50 microgL(-1). No matrix effect was found, and recoveries between 97 and 110% were obtained. The precision of the method was good, and the achieved variation coefficients were below 12%. The reliability of the proposed approach has been tested by analyzing a microsample of fogwater collected from leaf surfaces.

Deacidification of oils and fats of biological origine by aqueous solutions of tertiary amines*

Directory of Open Access Journals (Sweden)

Peter Siegfried

2001-01-01

Full Text Available Deacidification of triacylglycerols by extraction is investigated using aqueous solutions of amines as extractants. Tertiary amines with boiling points ranging between 100° and 170°C, such as 2-methylamino-diethanol, 2-dimethylamino-ethanol, 4-methylmorpholine, 1-dimethylamino-2-propanol etc. were found to be suitable substances. Especially the deacidification by aqueous solutions of 2-dimethylamino-ethanol (DMAE was amply investigated as it is used as an active agent in remedies. Amazingly gelatinous soap stocks are not formed, when the concentration of DMAE exceeds 20% if the free fatty acid content of the oil is below 15%. Two liquid phases are formed in systems composed of triacylglyceroles and aqueous solutions containing 20 to 80% DMAE. Palm oil containing 4.3 wt.% free fatty acids was mixed with an equal amount of an aqueous solution of 30 wt.% DMAE at 60°C. In equilibrium an extract containing 86 wt.% free fatty acids (solvents deducted and a raffinate of 0.09 wt.% free fatty acids are obtained. Loss of neutral oil being 0.7 wt.%.

A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

NARCIS (Netherlands)

Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

2005-01-01

A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

Determination of aliphatic amines in mineral flotation liquors and reagents by high-performance liquid chromatography after derivatization with 4-chloro-7-nitrobenzofurazan.

Science.gov (United States)

Hao, F; Lwin, T; Bruckard, W J; Woodcock, J T

2004-11-05

The method described here fulfils the need for a suitable analytical method to determine the concentrations of single and mixed aliphatic amines in the range from hexylamine (C6) to octadecylamine (C18) in flotation test solutions and in commercial flotation collectors. Amines do not have a UV-vis spectrum in aqueous solution but by reacting an amine-containing solution with 4-chloro-7-nitrobenzofurazan solution (chloro-NBD), derivatized products (amino-NBDs) are formed which have absorbance maxima at 470nm. Excess chloro-NBD and the amino-NBDs can be separated from each other by high-performance liquid chromatography (HPLC) and their concentrations measured with a UV-vis detector. Important variables in the derivatization stage are pH, temperature, chloro-NBD concentration, and reaction time, all of which interact with each other. A three-stage statistical procedure was used to determine the optimum conditions. In each stage, an 8-test design was used in which a high and low limit was set for each variable, and the chromatogram peak area of the derived amino-NBD was measured. The optimum derivatization conditions established were pH 8.9, chloro-NBD concentration 0.20% (w/v), temperature 70 degrees C, and reaction time 60 min. Optimum elution conditions for chromatography were an eluent containing 80% (v/v) acetonitrile in aqueous solution containing 40mM acetic acid at pH 4.5. With a flow rate of 2.0 ml/min, dodecylamine had a retention time of about 3 min, whereas octadecylamine had a retention time of 44 min. Straight-line calibration curves were obtained up to at least 200 ppm of amine in solution. The lower limit of detection was estimated to be 0.05 microM (10ppb) with a signal to noise ratio of 3. No interfering substances were found. The method was successfully applied to the analysis of solutions from an actual flotation test and to a solid commercial amine.

Thermodynamic properties of donor-acceptor complexes of tertiary amine with aryl ketones in hexane medium

Energy Technology Data Exchange (ETDEWEB)

Kumar, R. [Department of Physics, The New College, Chennai 600 014 (India); Jayakumar, S. [Department of Physics, R.K.M. Vivekananda College, Chennai 600 004 (India); Kannappan, V., E-mail: vkannappan@hotmail.com [Department of Chemistry, Presidency College, Chennai 600 005 (India)

2012-05-20

Highlights: Black-Right-Pointing-Pointer Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. Black-Right-Pointing-Pointer Formation of CT complexes is found between tertiary amine with aryl ketones. Black-Right-Pointing-Pointer Stability constant values are computed by ultrasonic and spectral methods are compared. Black-Right-Pointing-Pointer The trend in the 'K' suggests that substituents in ketones influence the stabilities of these complexes. Black-Right-Pointing-Pointer The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15-313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute-solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor-acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy ({Delta}G), enthalpy ({Delta}H) and entropy ({Delta}S) changes for complex formation are computed and discussed.

Vapor pressure and enthalpy of vaporization of aliphatic propanediamines

International Nuclear Information System (INIS)

Verevkin, Sergey P.; Chernyak, Yury

2012-01-01

Highlights: ► We measured vapor pressure of four aliphatic 1,3-diamines. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available data in the literature. ► A group-contribution method for prediction was developed. - Abstract: Vapor pressures of four aliphatic propanediamines including N-methyl-1,3-propanediamine (MPDA), N,N-dimethyl-1,3-propanediamine (DMPDA), N,N-diethyl-1,3-propanediamine (DEPDA) and N,N,N′,N′-tetramethyl-1,3-propanediamine (4MPDA) were measured using the transpiration method. The vapor pressures developed in this work and reported in the literature were used to derive molar enthalpy of vaporization values at the reference temperature 298.15 K. An internal consistency check of the enthalpy of vaporization was performed for the aliphatic propanediamines studied in this work. A group-contribution method was developed for the validation and prediction vaporization enthalpies of amines and diamines.

The distribution and adsorption behavior of aliphatic amines in marine and lacustrine sediments

Science.gov (United States)

Wang, Xu-chen; Lee, Cindy

1990-10-01

The methylated amines—monomethyl-, dimethyl-, and trimethyl amine (MMA, DMA, TMA)—are commonly found in aquatic environments, apparently as a result of decomposition processes. Adsorption of these amines to clay minerals and organic matter significantly influences their distribution in sediments. Laboratory measurements using 14C-radiolabelled amines and application of a linear partitioning model resulted in calculated adsorption coefficients of 2.4-4.7 (MMA), 3.3 (DMA), and 3.3-4.1 (TMA). Further studies showed that adsorption of amines is influenced by salinity of the porewaters, and clay mineral and organic matter content of the sediment solid phase. Concentrations of monomethyl- and dimethyl amine were measured in the porewaters and the solid phase of sediment samples collected from Flax Pond and Lake Ronkonkoma (NY), Long Island Sound, and the coastal Peru upwelling area. These two amines were present in all sediments investigated. A clear seasonal increase in the solid-phase concentration of MMA and DMA in Flax Pond sediments was likely related to the annual senescence of salt marsh grasses, either directly as a source of these compounds or indirectly by providing additional exchange capacity to the sediments. The distribution of amines in the solid and dissolved phases observed in all sediments investigated suggests that the distribution of these compounds results from a balance among production, decomposition, and adsorption processes.

Synthesis of 3-Bromotetronamides via Amination of 3,4-Dibromofuran-2(5H)-one

Energy Technology Data Exchange (ETDEWEB)

Cunha, Silvio; Oliveira, Caio C., E-mail: silviodc@ufba.b [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Instituto Nacional de Ciencia e Tecnologia (INCT) em Energia, Salvador, BA (Brazil); Sabino, Jose R. [Universidade Federal de Goias (IF/UFG), Goiania (Brazil). Inst. de Fisica

2011-07-01

This work describes the direct synthesis of 3-bromotetronamides in good yields through the reaction of 3,4-dibromofuran-2(5H)-one, obtained from furfural, with primary and secondary amines. Aromatic amines were more tolerated than aliphatic and heteroaromatic ones. The X-ray structures of five derivatives are described. (author)

Third phase formation in organic solutions in the extraction of mono-acids by tertiary trialcoyl-amines diluted in very slightly polar organic solvents

International Nuclear Information System (INIS)

Robaglia, Michele

1973-01-01

The phenomena of third phase formation which can occur during the extraction of an acid with a tertiary amine diluted in a low polarity diluent are studied. In the first part a system including water (TnOA - C 6 H 12 - HCl - H 2 O) is compared with an anhydrous system (TnOA - C 6 H 12 - HCl - N 2 ). There are two kinds of gaps. One during amine salification, another one during the extraction of excess acid. The important part of the water content of the organic phase is demonstrated. The presence of water enhances the gaps. The polar water molecules are dissolved inside the tri-octylamine salt micelles. The heavy phase is formed by aggregates, the light phase represents the solubility of the non soluble species in the medium. In the second part are studied the influence of some parameters (like nature of diluent, acid, amine and temperature) on the gaps formation and on the extraction of excess acid and water. In every cases the part played by water remains the same. Finally some comparisons are made between tertiary systems and binary systems which formed them. The binary systems were studied by the mean of crystallization curves. (author) [fr

Stereoinversion of tertiary alcohols to tertiary-alkyl isonitriles and amines.

Science.gov (United States)

Pronin, Sergey V; Reiher, Christopher A; Shenvi, Ryan A

2013-09-12

The SN2 reaction (bimolecular nucleophilic substitution) is a well-known chemical transformation that can be used to join two smaller molecules together into a larger molecule or to exchange one functional group for another. The SN2 reaction proceeds in a very predictable manner: substitution occurs with inversion of stereochemistry, resulting from the 'backside attack' of the electrophilic carbon by the nucleophile. A significant limitation of the SN2 reaction is its intolerance for tertiary carbon atoms: whereas primary and secondary alcohols are viable precursor substrates, tertiary alcohols and their derivatives usually either fail to react or produce stereochemical mixtures of products. Here we report the stereochemical inversion of chiral tertiary alcohols with a nitrogenous nucleophile facilitated by a Lewis-acid-catalysed solvolysis. The method is chemoselective against secondary and primary alcohols, thereby complementing the selectivity of the SN2 reaction. Furthermore, this method for carbon-nitrogen bond formation mimics a putative biosynthetic step in the synthesis of marine terpenoids and enables their preparation from the corresponding terrestrial terpenes. We expect that the general attributes of the methodology will allow chiral tertiary alcohols to be considered viable substrates for stereoinversion reactions.

N-heterocyclic carbene copper(I) catalysed N-methylation of amines using CO2

KAUST Repository

Santoro, Orlando

2015-09-30

The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(I) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.

N-heterocyclic carbene copper(I) catalysed N-methylation of amines using CO2

KAUST Repository

Santoro, Orlando; Lazreg, Faï ma; Minenkov, Yury; Cavallo, Luigi; Cazin, Catherine S. J.

2015-01-01

The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(I) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.

Regulation of carbon partitioning into carotenes by MPTA, a substituted tertiary amine

Energy Technology Data Exchange (ETDEWEB)

Madhavan, S.; Rosenfield, C.L.; Benedict, C.R.

1986-04-01

In mature citrus fruits, synthesis and turnover of carotenes appears to be low. Treatment of lemon pieces with the substituted tertiary amine, 2-(4-methylphenoxyl)triethylamine, MPTA, induces the synthesis of carotenes. Exposure of tissue slices (lemon flavedo) to MPTA for 72 hrs results in the production of 29.6 ..mu..g gfrwt/sup -1/ lycopene whereas control slices showed only trace amounts of lycopene. An identical incorporation of /sup 14/C-glucose into sugars, amino acids and organic acids, in both treated and control tissue slices indicates the non-disturbance of fruit respiration by MPTA treatment. Incorporation of /sup 14/C-glucose into carotenes is negligible in mature citrus fruits, but in MPTA treated tissue slices there is a pronounced incorporation of /sup 14/C-glucose into carotenes. MPTA treatment induces the synthesis of carotene enzymes, thus effecting an increased partitioning of glucose into the MVA pathway for carotene synthesis.

Regulation of carbon partitioning into carotenes by MPTA, a substituted tertiary amine

International Nuclear Information System (INIS)

Madhavan, S.; Rosenfield, C.L.; Benedict, C.R.

1986-01-01

In mature citrus fruits, synthesis and turnover of carotenes appears to be low. Treatment of lemon pieces with the substituted tertiary amine, 2-(4-methylphenoxyl)triethylamine, MPTA, induces the synthesis of carotenes. Exposure of tissue slices (lemon flavedo) to MPTA for 72 hrs results in the production of 29.6 μg gfrwt -1 lycopene whereas control slices showed only trace amounts of lycopene. An identical incorporation of 14 C-glucose into sugars, amino acids and organic acids, in both treated and control tissue slices indicates the non-disturbance of fruit respiration by MPTA treatment. Incorporation of 14 C-glucose into carotenes is negligible in mature citrus fruits, but in MPTA treated tissue slices there is a pronounced incorporation of 14 C-glucose into carotenes. MPTA treatment induces the synthesis of carotene enzymes, thus effecting an increased partitioning of glucose into the MVA pathway for carotene synthesis

A General Catalyst for Site-Selective C(sp(3))-H Bond Amination of Activated Secondary over Tertiary Alkyl C(sp(3))-H Bonds.

Science.gov (United States)

Scamp, Ryan J; Jirak, James G; Dolan, Nicholas S; Guzei, Ilia A; Schomaker, Jennifer M

2016-06-17

The discovery of transition metal complexes capable of promoting general, catalyst-controlled and selective carbon-hydrogen (C-H) bond amination of activated secondary C-H bonds over tertiary alkyl C(sp(3))-H bonds is challenging, as substrate control often dominates when reactive nitrene intermediates are involved. In this letter, we report the design of a new silver complex, [(Py5Me2)AgOTf]2, that displays general and good-to-excellent selectivity for nitrene insertion into propargylic, benzylic, and allylic C-H bonds over tertiary alkyl C(sp(3))-H bonds.

Carbon Dioxide-Mediated C(sp3)-H Arylation of Amine Substrates.

Science.gov (United States)

Kapoor, Mohit; Liu, Daniel; Young, Michael C

2018-05-25

Elaborating amines via C-H functionalization has been an important area of research over the past decade but has generally relied on an added directing group or sterically hindered amine approach. Since free-amine-directed C(sp 3 )-H activation is still primarily limited to cyclization reactions and to improve the sustainability and reaction scope of amine-based C-H activation, we present a strategy using CO 2 in the form of dry ice that facilitates intermolecular C-H arylation. This methodology has been used to enable an operationally simple procedure whereby 1° and 2° aliphatic amines can be arylated selectively at their γ-C-H positions. In addition to potentially serving as a directing group, CO 2 has also been demonstrated to curtail the oxidation of sensitive amine substrates.

Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

Science.gov (United States)

Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

2013-02-01

Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Products of tungstate ion interaction with primary aliphatic amines

International Nuclear Information System (INIS)

Skrylev, L.D.; Sejfullina, I.I.; Purich, A.N.; Babinets, S.K.

1982-01-01

Using the methods of conductometric titration, IR-spectroscopic and thermographic analyses precipitates formed in the process of interaction of diluted aqueous solutions of sodium tungstate with alcoholic solutions of dodecyl-, tetradecyl- and octadecylamine have been studied. It is shown that as a result of interaction tungstates of corresponding amines are formed. The structure and thermal stability of singled out products are determined

Conversion of alcohols to enantiopure amines through dual-enzyme hydrogen-borrowing cascades.

Science.gov (United States)

Mutti, Francesco G; Knaus, Tanja; Scrutton, Nigel S; Breuer, Michael; Turner, Nicholas J

2015-09-25

α-Chiral amines are key intermediates for the synthesis of a plethora of chemical compounds at industrial scale. We present a biocatalytic hydrogen-borrowing amination of primary and secondary alcohols that allows for the efficient and environmentally benign production of enantiopure amines. The method relies on a combination of two enzymes: an alcohol dehydrogenase (from Aromatoleum sp., Lactobacillus sp., or Bacillus sp.) operating in tandem with an amine dehydrogenase (engineered from Bacillus sp.) to aminate a structurally diverse range of aromatic and aliphatic alcohols, yielding up to 96% conversion and 99% enantiomeric excess. Primary alcohols were aminated with high conversion (up to 99%). This redox self-sufficient cascade possesses high atom efficiency, sourcing nitrogen from ammonium and generating water as the sole by-product. Copyright © 2015, American Association for the Advancement of Science.

Two-dimensional inorganic–organic hybrid semiconductors composed of double-layered ZnS and monoamines with aromatic and heterocyclic aliphatic rings: Syntheses, structures, and properties

International Nuclear Information System (INIS)

Wang, Sujing; Li, Jing

2015-01-01

As an addition to the II–VI based inorganic–organic hybrid semiconductor family, five new two-dimensional (2D) double-layered structures have been synthesized employing monoamines with different aromatic or heterocyclic aliphatic rings. Zn 2 S 2 (bza) (1), Zn 2 S 2 (mbza) (2), Zn 2 S 2 (fbza) (3), Zn 2 S 2 (pca) (4), and Zn 2 S 2 (thfa) (5) (bza=benzylamine, mbza=4-methoxybenzylamine, fbza=4-flurobenzylamine, pca=3-picolylamine, and thfa=tetrahydrofurfurylamine) are prepared by solvothermal reactions and characterized by different analytical methods, including powder X-ray diffraction, optical diffuse reflection, thermogravimetric analysis and photoluminescence spectroscopy. The powder X-ray diffraction patterns show that all five compounds adopt 2D double-layered structures. Optical diffuse reflectance spectra of these compounds suggest that they have notably lower band gaps than those of the similar compounds composed of aliphatic alkyl amines. Their photoluminescence properties and thermal stability are also analyzed. - Graphical abstract: Five new members of two-dimensional double-layered 2D-Zn 2 S 2 (L) (L=Ligand) structures employing monoamines with different aromatic or heterocyclic aliphatic rings have been designed, synthesized, and characterized. - Highlights: • A new sub-family of II-VI based hybrid semiconductors are designed, synthesized, and structurally characterized using amines with aromatic or aliphatic cyclic rings. • These compounds have notably lower band gaps than those made of aliphatic alkyl amines, greatly broadening the range of band gaps of this material family. • They emit strongly with systematically tunable emission intensity and energy

Novel cationic surfactants from fatty acids and their corrosion inhibition efficiency for carbon steel pipelines in 1 M HCl

Directory of Open Access Journals (Sweden)

A.M. Al-Sabagh

2011-06-01

Full Text Available Four fatty acids were used as a source of alkyl halides. Untraditionally tertiary amines were prepared by ethoxylation of aromatic and aliphatic fatty amines. These alkyl halide and tertiary amines were used to prepare 20 cationic quaternary ammonium surfactants (QASS. Their chemical structures were characterized and they tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured using, weight loss and potentiodynamic polarization methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. From the obtained data it was found that, the inhibition efficiency increases with increasing the inhibitor concentration until the optimum one. Also, it was found that the inhibition efficiency of QASs which based on ethoxylated aromatic tertiary amine is greater than the obtained efficiencies by the QASs which based on ethoxylated aliphatic tertiary amines. The QASs based on alkyl halide C16 exhibited the maximum inhibition efficiency 98.8%. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir’s adsorption isotherm. The quantum chemical calculations were done for some selected quaternary ammonium compounds based on their chemical structures QL1,4,5–QP3,4,5. The following quantum chemical indices such as the bond length, bond angle, charge density distribution, highest occupied molecular orbital (HOMO, lowest unoccupied molecular orbital (LUMO, energy gap ΔE = HOMO − LUMO, and dipole moment (u were considered. The relation between these parameters and the inhibition efficiencies was explained on the light of the chemical structure of the used inhibitors.

Modification Of Poly(glycidyl Methacrylate) Grafted Onto Crosslinked Pvc With Tertiary Amine Group And Use For Removing Acidic Dyes From Water

OpenAIRE

Yorgun, Gülden

2009-01-01

In this study, glycidylmethacrylate is grafted onto partially dehydrochlorinated poly(vinyl chloride) (DHPVC) using ATRP method and polymerization kinetics of the reaction is studied. Then, the polymeric resin was interacted with excess of diethylamine, giving a tertiary amine containing sorbent. Surface initiated polymerizations have been widely used to overcome inadequate properties of poly(vinylchloride) (PVC). Epoxy group is one of the most important type to be integrated into polymers. T...

Determination of rate constants of N-alkylation of primary amines by 1H NMR spectroscopy.

Science.gov (United States)

Li, Chenghong

2013-09-05

Macromolecules containing N-diazeniumdiolates of secondary amines are proposed scaffolds for controlled nitrogen oxide (NO) release medical applications. Preparation of these compounds often involves converting primary amine groups to secondary amine groups through N-alkylation. However, N-alkylation results in not only secondary amines but tertiary amines as well. Only N-diazeniumdiolates of secondary amines are suitable for controlled NO release; therefore, the yield of secondary amines is crucial to the total NO load of the carrier. In this paper, (1)H NMR spectroscopy was used to estimate the rate constants for formation of secondary amine (k1) and tertiary amine (k2) for alkylation reagents such as propylene oxide (PO), methyl acrylate (MA), and acrylonitrile (ACN). At room temperature, the ratio of k2/k1 for the three reactions was found to be around 0.50, 0.026, and 0.0072.

Mechanistic insights into the oxidative dehydrogenation of amines to nitriles in continuous flow

DEFF Research Database (Denmark)

Corker, Emily C.; Ruiz-Martínez, Javier; Riisager, Anders

2015-01-01

The oxidative dehydrogenation of various aliphatic amines to their corresponding nitrile compounds using RuO2/Al2O3 catalysts in air was successfully applied to a continuous flow reaction. Conversions of amines (up to >99%) and yields of nitriles (up to 77%) varied depending on reaction conditions...... and the amine utilised. The presence of water was found to be important for the activity and stability of the RuO2/Al2O3 catalyst. The Hammett relationship and in situ infrared spectroscopy were applied to divulge details about the catalytic mechanism of the oxidative dehydrogenation of amines over RuO2/Al2O3...

Amines as extracting agents for the quantitative determinations of actinides in biological samples

International Nuclear Information System (INIS)

Singh, N.P.

1987-01-01

The use of amines (primary, secondary and tertiary chains and quaternary ammonium salts) as extracting agents for the quantitative determination of actinides in biological samples is reviewed. Among the primary amines, only Primene JM-T is used to determine Pu in urine and bone. No one has investigated the possibility of using secondary amines to quantitatively extract actinides from biological samples. Among the tertiary amines, tri-n-octylamine, tri-iso-octylamine, tyricaprylamine (Alamine) and trilaurylamine (tridodecylamine) are used extensively to extract and separate the actinides from biological samples. Only one quaternary ammonium salt, methyltricapryl ammonium chloride (Aliquat-336), is used to extract Pu from biological samples. (author) 28 refs

Molecular Evolution and Functional Divergence of Trace Amine-Associated Receptors.

Directory of Open Access Journals (Sweden)

Seong-Il Eyun

Full Text Available Trace amine-associated receptors (TAARs are a member of the G-protein-coupled receptor superfamily and are known to be expressed in olfactory sensory neurons. A limited number of molecular evolutionary studies have been done for TAARs so far. To elucidate how lineage-specific evolution contributed to their functional divergence, we examined 30 metazoan genomes. In total, 493 TAAR gene candidates (including 84 pseudogenes were identified from 26 vertebrate genomes. TAARs were not identified from non-vertebrate genomes. An ancestral-type TAAR-like gene appeared to have emerged in lamprey. We found four therian-specific TAAR subfamilies (one eutherian-specific and three metatherian-specific in addition to previously known nine subfamilies. Many species-specific TAAR gene duplications and losses contributed to a large variation of TAAR gene numbers among mammals, ranging from 0 in dolphin to 26 in flying fox. TAARs are classified into two groups based on binding preferences for primary or tertiary amines as well as their sequence similarities. Primary amine-detecting TAARs (TAAR1-4 have emerged earlier, generally have single-copy orthologs (very few duplication or loss, and have evolved under strong functional constraints. In contrast, tertiary amine-detecting TAARs (TAAR5-9 have emerged more recently and the majority of them experienced higher rates of gene duplications. Protein members that belong to the tertiary amine-detecting TAAR group also showed the patterns of positive selection especially in the area surrounding the ligand-binding pocket, which could have affected ligand-binding activities and specificities. Expansions of the tertiary amine-detecting TAAR gene family may have played important roles in terrestrial adaptations of therian mammals. Molecular evolution of the TAAR gene family appears to be governed by a complex, species-specific, interplay between environmental and evolutionary factors.

Two-dimensional inorganic–organic hybrid semiconductors composed of double-layered ZnS and monoamines with aromatic and heterocyclic aliphatic rings: Syntheses, structures, and properties

Energy Technology Data Exchange (ETDEWEB)

Wang, Sujing; Li, Jing, E-mail: jingli@rutgers.edu

2015-04-15

As an addition to the II–VI based inorganic–organic hybrid semiconductor family, five new two-dimensional (2D) double-layered structures have been synthesized employing monoamines with different aromatic or heterocyclic aliphatic rings. Zn{sub 2}S{sub 2}(bza) (1), Zn{sub 2}S{sub 2}(mbza) (2), Zn{sub 2}S{sub 2}(fbza) (3), Zn{sub 2}S{sub 2}(pca) (4), and Zn{sub 2}S{sub 2}(thfa) (5) (bza=benzylamine, mbza=4-methoxybenzylamine, fbza=4-flurobenzylamine, pca=3-picolylamine, and thfa=tetrahydrofurfurylamine) are prepared by solvothermal reactions and characterized by different analytical methods, including powder X-ray diffraction, optical diffuse reflection, thermogravimetric analysis and photoluminescence spectroscopy. The powder X-ray diffraction patterns show that all five compounds adopt 2D double-layered structures. Optical diffuse reflectance spectra of these compounds suggest that they have notably lower band gaps than those of the similar compounds composed of aliphatic alkyl amines. Their photoluminescence properties and thermal stability are also analyzed. - Graphical abstract: Five new members of two-dimensional double-layered 2D-Zn{sub 2}S{sub 2}(L) (L=Ligand) structures employing monoamines with different aromatic or heterocyclic aliphatic rings have been designed, synthesized, and characterized. - Highlights: • A new sub-family of II-VI based hybrid semiconductors are designed, synthesized, and structurally characterized using amines with aromatic or aliphatic cyclic rings. • These compounds have notably lower band gaps than those made of aliphatic alkyl amines, greatly broadening the range of band gaps of this material family. • They emit strongly with systematically tunable emission intensity and energy.

Visible-Light-Promoted Metal-Free Aerobic Oxidation of Primary Amines to Acids and Lactones.

Science.gov (United States)

Cheng, Xiaokai; Yang, Bo; Hu, Xingen; Xu, Qing; Lu, Zhan

2016-12-05

A unique metal-free aerobic oxidation of primary amines via visible light photocatalytic double carbon-carbon bonds cleavage and multi carbon-hydrogen bonds oxidation was observed. Aerobic oxidation of primary amines could be controlled to afford acids by using dioxane with 18 W CFL, and lactones by using DMF with 8 W green LEDs, respectively. A plausible mechanism was proposed based on control experiments. This observation showed direct evidences for the fragmentation in the aerobic oxidation of aliphatic primary amines. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nitrile-functionalized tertiary amines as highly efficient and reversible SO2 absorbents.

Science.gov (United States)

Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk; Lee, Hyunjoo; Kim, Hoon Sik; Lee, Je Seung

2014-01-15

Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO2 absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption-desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO2 through oxygen atom, forming an ionic compound with a covalently bound OSO2(-) group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO2 through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities. Copyright © 2013 Elsevier B.V. All rights reserved.

New potential of the reductive alkylation of amines

International Nuclear Information System (INIS)

Gusak, K N; Ignatovich, Zh V; Koroleva, E V

2015-01-01

Available data on the reductive alkylation of amines with carbonyl compounds — a key method for the preparation of secondary and tertiary amines — are described systematically. The review provides information on the relevant reducing agents and catalysts and on the use of chiral catalysts in stereo- and enantiocontrolled reactions of amine synthesis. The effect of the reactant and catalyst structures on the reaction rates and chemo- and stereo(enantio)selectivity is considered. The bibliography includes 156 references

A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

International Nuclear Information System (INIS)

Largeron, Martine

2009-01-01

A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

Energy Technology Data Exchange (ETDEWEB)

Largeron, Martine [UMR CNRS 8638, Synthese et Structure de Molecules d' nteret Pharmacologique, Universite Paris Descartes, Faculte des Sciences Pharmaceutiques et Biologiques, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)], E-mail: martine.largeron@parisdescartes.fr

2009-09-01

A one-pot electrochemically induced oxidation-imine formation-reduction route to secondary amines is described in detail. The key step of the process consists of the o-iminoquinone-mediated chemoselective catalytic oxidation of a primary aliphatic amine substrate, in the presence of a second amine used as the alkylating agent. Through the examination of the scope of the reaction by systematically varying both amine substrate and amine alkylating agent, it can be shown that this reaction sequence, leaving ammonia as the sole by-product, allows the rapid synthesis of various secondary amines in moderate to good yields. This process, that highlights the pre-eminent green advantages of electrochemical synthesis, especially the utilization of electricity as energy instead of chemical reagents, high atom economy as well as ambient temperature and pressure, could be a mild alternative to already reported synthetic methods.

Saturated amine oxides: Part 8. Hydroacridines: Part 27. Effects of N-oxidation and of N-quaternization on the 15N NMR chemical shifts of N-methylpiperidine-derived mono-, bi-, and tricycloaliphatic tertiary amines.

Science.gov (United States)

Potmischil, Francisc; Duddeck, Helmut; Nicolescu, Alina; Deleanu, Calin

2007-03-01

The (15)N chemical shifts of 13 N-methylpiperidine-derived mono-, bi- and tricycloaliphatic tertiary amines, their methiodides and their N-epimeric pairs of N-oxides were measured, and the contributions of specific structural parameters to the chemical shifts were determined by multilinear regression analysis. Within the examined compounds, the effects of N-oxidation upon the (15)N chemical shifts of the amines vary from +56 ppm to +90 ppm (deshielding), of which approx. +67.7 ppm is due to the inductive effect of the incoming N(+)--O(-) oxygen atom, whereas the rest is due to the additive shift effects of the various C-alkyl substituents of the piperidine ring. The effects of quaternization vary from -3.1 ppm to +29.3 ppm, of which approx. +8.9 ppm is due to the inductive effect of the incoming N(+)--CH(3) methyl group, and the rest is due to the additive shift effects of the various C-alkyl substituents of the piperidine ring. The shift effects of the C-alkyl substituents in the amines, the N-oxides and the methiodides are discussed. Copyright (c) 2007 John Wiley & Sons, Ltd.

General Allylic C–H Alkylation with Tertiary Nucleophiles

Science.gov (United States)

2015-01-01

A general method for intermolecular allylic C–H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C–H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C–H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C–H reactivity are illustrated in an allylic C–H alkylation/Diels–Alder reaction cascade: a reactive diene is generated via intermolecular allylic C–H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids. PMID:24641574

General allylic C-H alkylation with tertiary nucleophiles.

Science.gov (United States)

Howell, Jennifer M; Liu, Wei; Young, Andrew J; White, M Christina

2014-04-16

A general method for intermolecular allylic C-H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C-H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C-H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C-H reactivity are illustrated in an allylic C-H alkylation/Diels-Alder reaction cascade: a reactive diene is generated via intermolecular allylic C-H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids.

Solvent-free functionalization of carbon nanotube buckypaper with amines

International Nuclear Information System (INIS)

Basiuk, Elena V.; Ramírez-Calera, Itzel J.; Meza-Laguna, Victor; Abarca-Morales, Edgar; Pérez-Rey, Luis A.; Re, Marilena; Prete, Paola; Lovergine, Nico

2015-01-01

Graphical abstract: - Abstract: We demonstrate the possibility of fast and efficient solvent-free functionalization of buckypaper (BP) mats prefabricated from oxidized multiwalled carbon nanotubes (MWCNTs-ox), by using three representative amines of different structure: one monofunctional aliphatic amine, octadecylamine (ODA), one monofunctional aromatic amine, 1-aminopyrene (AP), and one aromatic diamine, 1,5-diaminonaphthalene (DAN). The functionalization procedure, which relies on the formation of amide bonds with carboxylic groups of MWCNTs-ox, is performed at 150–180 °C under reduced pressure and takes about 4 h including auxiliary degassing. The amine-treated BP samples (BP-ODA, BP-AP and BP-DAN, respectively) were characterized by means of a variety of analytical techniques such as Fourier-transform infrared and Raman spectroscopy, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, scanning helium ion microscopy, and atomic force microscopy. The highest amine content was found for BP-ODA, and the lowest one was observed for BP-DAN, with a possible contribution of non-covalently bonded amine molecules in all three cases. Despite of some differences in spectral and morphological characteristics for amine-functionalized BP samples, they have in common a dramatically increased stability in water as compared to pristine BP and, on the other hand, a relatively invariable electrical conductivity.

Cu/Nitroxyl Catalyzed Aerobic Oxidation of Primary Amines into Nitriles at Room Temperature

OpenAIRE

Kim, Jinho; Stahl, Shannon S.

2013-01-01

An efficient catalytic method has been developed for aerobic oxidation of primary amines to the corresponding nitriles. The reactions proceed at room temperature and employ a catalyst consisting of (4,4′-tBu2bpy)CuI/ABNO (ABNO = 9-azabicyclo[3.3.1]nonan-3-one N-oxyl). The reactions exhibit excellent functional group compatibility and substrate scope, and are effective with benzylic, allylic and aliphatic amines. Preliminary mechanistic studies suggest that aerobic oxidation of the Cu catalyst...

Amine synergism in uranium extraction

International Nuclear Information System (INIS)

Rinelli, G.; Abbruzzese, C.

1977-01-01

Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)

Role of amine structure on carbon dioxide adsorption from ultradilute gas streams such as ambient air.

Science.gov (United States)

Didas, Stephanie A; Kulkarni, Ambarish R; Sholl, David S; Jones, Christopher W

2012-10-01

A fundamental study on the adsorption properties of primary, secondary, and tertiary amine materials is used to evaluate what amine type(s) are best suited for ultradilute CO(2) capture applications. A series of comparable materials comprised of primary, secondary, or tertiary amines ligated to a mesoporous silica support via a propyl linker are used to systematically assess the role of amine type. Both CO(2) and water adsorption isotherms are presented for these materials in the range relevant to CO(2) capture from ambient air and it is demonstrated that primary amines are the best candidates for CO(2) capture from air. Primary amines possess both the highest amine efficiency for CO(2) adsorption as well as enhanced water affinity compared to other amine types or the bare silica support. The results suggest that the rational design of amine adsorbents for the extraction of CO(2) from ambient air should focus on adsorbents rich in primary amines. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvent effects on the magnetic shielding of tertiary butyl alcohol

African Journals Online (AJOL)

)4 and tetramethyl ammonium cation N(CH3)4(+) have also been presented. KEY WORDS: Solvent effects, Magnetic shielding, Tertiary butyl alcohol, Tertiary butyl amine, Continuum solvation calculations, Chemical shift estimation methods

Supramolecular Recognition Allows Remote, Site-Selective C-H Oxidation of Methylenic Sites in Linear Amines.

Science.gov (United States)

Olivo, Giorgio; Farinelli, Giulio; Barbieri, Alessia; Lanzalunga, Osvaldo; Di Stefano, Stefano; Costas, Miquel

2017-12-18

Site-selective C-H functionalization of aliphatic alkyl chains is a longstanding challenge in oxidation catalysis, given the comparable relative reactivity of the different methylenes. A supramolecular, bioinspired approach is described to address this challenge. A Mn complex able to catalyze C(sp 3 )-H hydroxylation with H 2 O 2 is equipped with 18-benzocrown-6 ether receptors that bind ammonium substrates via hydrogen bonding. Reversible pre-association of protonated primary aliphatic amines with the crown ether selectively exposes remote positions (C8 and C9) to the oxidizing unit, resulting in a site-selective oxidation. Remarkably, such control of selectivity retains its efficiency for a whole series of linear amines, overriding the intrinsic reactivity of C-H bonds, no matter the chain length. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Redox self-sufficient whole cell biotransformation for amination of alcohols.

Science.gov (United States)

Klatte, Stephanie; Wendisch, Volker F

2014-10-15

Whole cell biotransformation is an upcoming tool to replace common chemical routes for functionalization and modification of desired molecules. In the approach presented here the production of various non-natural (di)amines was realized using the designed whole cell biocatalyst Escherichia coli W3110/pTrc99A-ald-adh-ta with plasmid-borne overexpression of genes for an l-alanine dehydrogenase, an alcohol dehydrogenase and a transaminase. Cascading alcohol oxidation with l-alanine dependent transamination and l-alanine dehydrogenase allowed for redox self-sufficient conversion of alcohols to the corresponding amines. The supplementation of the corresponding (di)alcohol precursors as well as amino group donor l-alanine and ammonium chloride were sufficient for amination and redox cofactor recycling in a resting buffer system. The addition of the transaminase cofactor pyridoxal-phosphate and the alcohol dehydrogenase cofactor NAD(+) was not necessary to obtain complete conversion. Secondary and cyclic alcohols, for example, 2-hexanol and cyclohexanol were not aminated. However, efficient redox self-sufficient amination of aliphatic and aromatic (di)alcohols in vivo was achieved with 1-hexanol, 1,10-decanediol and benzylalcohol being aminated best. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cu/Nitroxyl Catalyzed Aerobic Oxidation of Primary Amines into Nitriles at Room Temperature.

Science.gov (United States)

Kim, Jinho; Stahl, Shannon S

2013-07-05

An efficient catalytic method has been developed for aerobic oxidation of primary amines to the corresponding nitriles. The reactions proceed at room temperature and employ a catalyst consisting of (4,4'- t Bu 2 bpy)CuI/ABNO (ABNO = 9-azabicyclo[3.3.1]nonan-3-one N -oxyl). The reactions exhibit excellent functional group compatibility and substrate scope, and are effective with benzylic, allylic and aliphatic amines. Preliminary mechanistic studies suggest that aerobic oxidation of the Cu catalyst is the turnover-limiting step of the reaction.

Strong cation exchange-type chiral stationary phase for enantioseparation of chiral amines in subcritical fluid chromatography.

Science.gov (United States)

Wolrab, Denise; Kohout, Michal; Boras, Mario; Lindner, Wolfgang

2013-05-10

A new strong cation exchange type chiral stationary phase (SCX CSP) based on a syringic acid amide derivative of trans-(R, R)-2-aminocyclohexanesulfonic acid was applied to subcritical fluid chromatography (SFC) for separation of various chiral basic drugs and their analogues. Mobile phase systems consisting of aliphatic alcohols as polar modifiers and a broad range of amines with different substitution patterns and lipophilicity were employed to evaluate the impact on the SFC retention and selectivity characteristics. The observed results point to the existence of carbonic and carbamic acid salts formed as a consequence of reactions occurring between carbon dioxide, the alcoholic modifiers and the amine species present in the sub/supercritical fluid medium, respectively. Evidence is provided that these species are essential for affecting ion exchange between the strongly acidic chiral selector units and the basic analytes, following the well-established stoichiometric displacement mechanisms. Specific trends were observed when different types of amines were used as basic additives. While ammonia gave rise to the formation of the most strongly eluting carbonic and carbamic salt species, simple tertiary amines consistently provided superior levels of enantioselectivity. Furthermore, trends in the chiral SFC separation characteristics were investigated by the systematic variation of the modifier content and temperature. Different effects of additives are interpreted in terms of changes in the relative concentration of the transient ionic species contributing to analyte elution, with ammonia-derived carbamic salts being depleted at elevated temperatures by decomposition. Additionally, in an effort to optimize SFC enantiomer separation conditions for selected analytes, the impact of the type of the organic modifier, temperature, flow rate and active back pressure were also investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

Study on synthesis, application and mechanism of benzophenone/amine initiator

International Nuclear Information System (INIS)

Xiong Wei; Liu Jinshui; Wen Yinjun; Wan Qizhong; Zhou Xianyan; Xiao Hanling; Yang Jianwen

1999-01-01

Through Michael addition reaction of trimethylolpropane triacrylate (TMPTA) with diethylamine (DEA), a new kind of tertiary amine derivative was synthesized and its structure was identified by 'H-NMR. When used in combination with benzophenone, this amine presented excellent curing speed and could be a substitute for initiator Darocur R 1173, which is effective but expensive. If so, the cost of UV-curable coatings can descend apparently. The functioning mechanism of benzophenone/amine bimolecular initiator was studied

Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

Science.gov (United States)

Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

2014-04-01

Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

Synthesis of Tertiary and Quaternary Amine Derivatives from Wood Resin as Chiral NMR Solvating Agents

Directory of Open Access Journals (Sweden)

Tiina Laaksonen

2015-11-01

Full Text Available Chiral tertiary and quaternary amine solvating agents for NMR spectroscopy were synthesized from the wood resin derivative (+-dehydroabietylamine (2. The resolution of enantiomers of model compounds [Mosher’s acid (3 and its n-Bu4N salt (4] (guests by (+-dehydroabietyl-N,N-dimethylmethanamine (5 and its ten different ammonium salts (hosts was studied. The best results with 3 were obtained using 5 while with 4 the best enantiomeric resolution was obtained using (+-dehydroabietyl-N,N-dimethylmethanaminium bis(trifluoromethane-sulfonimide (6. The compounds 5 and 6 showed a 1:1 complexation behaviour between the host and guest. The capability of 5 and 6 to recognize the enantiomers of various α-substituted carboxylic acids and their n-Bu4N salts in enantiomeric excess (ee determinations was demonstrated. A modification of the RES-TOCSY NMR pulse sequence is described, allowing the enhancement of enantiomeric discrimination when the resolution of multiplets is insufficient.

Investigations on organogermanium compounds; III. N-tributylgermyl-substituted aliphatic and heterocyclic amines

NARCIS (Netherlands)

Rijkens, F.; Janssen, M.J.; Kerk, G.J.M. van der

1965-01-01

A series of new organogermanium compounds containing a germanium‐nitrogen bond, in many of which the nitrogen atom forms part of an heterocyclic ring, are prepared, in some cases by new methods: transamination reactions and reactions of germoxanes with heterocyclic amines. Striking differences in

Berkelium (4) and cerium (4) extraction with tertiary amines

International Nuclear Information System (INIS)

Milyukova, M.S.; Malikov, D.A.; Myasoedov, B.V.

1978-01-01

Oxidation of indicator quantities of berkelium and cerium by a mixture of silver nitrate and ammonium persulfate in the solutions of nitric and sulfuric acid has been examined. The stability of the elements in a tetravalent state and their extraction by the solutions of ternary amines have been investigated. It has been established that berkelium and cerium oxidation under these conditions occurs under the effect of ions of divalent silver which is formed owing to oxidation of monovalent silver by peroxide sulfate ions. The following supposition has been put forward: a difference in the behaviour of tetravalent berkelium and cerium during their extraction by ternary amines is explained by their different stability in this state, but not by the formation of complex compounds with nitrate ions

Ni-Catalyzed Carbon-Carbon Bond-Forming Reductive Amination.

Science.gov (United States)

Heinz, Christoph; Lutz, J Patrick; Simmons, Eric M; Miller, Michael M; Ewing, William R; Doyle, Abigail G

2018-02-14

This report describes a three-component, Ni-catalyzed reductive coupling that enables the convergent synthesis of tertiary benzhydryl amines, which are challenging to access by traditional reductive amination methodologies. The reaction makes use of iminium ions generated in situ from the condensation of secondary N-trimethylsilyl amines with benzaldehydes, and these species undergo reaction with several distinct classes of organic electrophiles. The synthetic value of this process is demonstrated by a single-step synthesis of antimigraine drug flunarizine (Sibelium) and high yielding derivatization of paroxetine (Paxil) and metoprolol (Lopressor). Mechanistic investigations support a sequential oxidative addition mechanism rather than a pathway proceeding via α-amino radical formation. Accordingly, application of catalytic conditions to an intramolecular reductive coupling is demonstrated for the synthesis of endo- and exocyclic benzhydryl amines.

Ultrasound accelerated sulfonylation of amines by p-acetamidobenzenesulfonyl chloride using Mg–Al hydrotalcite as an efficient green base catalyst

DEFF Research Database (Denmark)

Truong, Binh Nhat; Le, Luong Huu; Chau, Duy-Khiem Nguyen

2016-01-01

The sulfonylation reaction of various aliphatic, alicyclic, aromatic, and hetero-aromatic amines with p-acetamidobenzenesulfonyl chloride has been investigated using different types of base catalysis under varied reaction conditions. Mg–Al hydrotalcite, characterizable as an inexpensive, reusable...

Efficient 'One Pot' Nitro Reduction-Protection of γ-Nitro Aliphatic Methyl Esters

OpenAIRE

Díaz-Coutiño, Francisco D.; Escalante, Jaime

2009-01-01

A simple and efficient protocol has been developed for the direct conversion of γ-nitro aliphatic methyl esters to N-(tert-butoxycarbonyl)amine methyl esters using NH4+HCO2- and Pd/C in the presence of (Boc)2O. There was a significant decrease in the reaction time under these conditions, increased yields and the purity of the products using this 'one pot' procedure. Un protocolo simple y eficiente de síntesis ha sido desarrollado para la conversión directa de metil ésteres de γ-nitro alifá...

Synthesis of Novel Aliphatic N-sulfonylamidino Thymine Derivatives by Cu(I)-catalyzed Three-component Coupling Reaction

OpenAIRE

Krstulović, Luka; Ismaili, Hamit; Višnjevac, Aleksandar; Glavaš-Obrovac, Ljubica; Žinić, Biserka

2012-01-01

A series of new aliphatic N-sulfonylamidino thymine derivatives containing nucleobase, N-sulfonyl and amidine pharmacophores in the structure were synthesized by Cu(I)-catalyzed threecomponent coupling of 1-propargyl thymine, benzenesulfonyl azides and amines or ammonium salts. Preliminary in vitro antitumor screening (human cervix adenocarcinoma -HeLa and leukemia cells - Jurkat) revealed promising activities of N,N-diethyl- (2) and N-4-cyanobenzyl- (6) derivatives of 4-acetamido...

Complementation of biotransformations with chemical C-H oxidation: copper-catalyzed oxidation of tertiary amines in complex pharmaceuticals.

Science.gov (United States)

Genovino, Julien; Lütz, Stephan; Sames, Dalibor; Touré, B Barry

2013-08-21

The isolation, quantitation, and characterization of drug metabolites in biological fluids remain challenging. Rapid access to oxidized drugs could facilitate metabolite identification and enable early pharmacology and toxicity studies. Herein, we compared biotransformations to classical and new chemical C-H oxidation methods using oxcarbazepine, naproxen, and an early compound hit (phthalazine 1). These studies illustrated the low preparative efficacy of biotransformations and the inability of chemical methods to oxidize complex pharmaceuticals. We also disclose an aerobic catalytic protocole (CuI/air) to oxidize tertiary amines and benzylic CH's in drugs. The reaction tolerates a broad range of functionalities and displays a high level of chemoselectivity, which is not generally explained by the strength of the C-H bonds but by the individual structural chemotype. This study represents a first step toward establishing a chemical toolkit (chemotransformations) that can selectively oxidize C-H bonds in complex pharmaceuticals and rapidly deliver drug metabolites.

Electrochemical and Quantum Chemical Study of Reactivity of Orthophthalaldehyde with Aliphatic Primary Amines

Czech Academy of Sciences Publication Activity Database

Donkeng Dazie, Joel; Liška, Alan; Ludvík, Jiří

2016-01-01

Roč. 163, č. 9 (2016), G127-G132 ISSN 0013-4651 R&D Projects: GA ČR GA13-21704S Institutional support: RVO:61388955 Keywords : electrochemistry * quantum chemical study * amines Subject RIV: CG - Electrochemistry Impact factor: 3.259, year: 2016

Using Amines and Alkanes as Thermal-Runaway Retardants for Lithium-Ion Battery

Science.gov (United States)

Shi, Yang

Thermal runaway imposes major challenges to large-scale lithium-ion batteries (LIBs). The working temperature of a LIB is usually around room temperature. However, upon mechanical abuse such as an impact or nail penetration, LIB cell components may fail and internal short circuits could be formed. As a result, a series of exothermic electrochemical reactions and decompositions would take place and the local temperature can rapidly increase. In this thesis, a few novel techniques are investigated to mitigate thermal runaway of LIBs. Mechanically triggered approach has been employed. Thermal-runaway retardant (TRR) is encapsulated in mechanically responsive packages made of materials inert to the battery environment, and upon external mechanical loadings the packages can be broken apart and release the TRR. This mechanism allows for the use of aggressive chemicals to suppress the short circuit discharge and reduce the subsequent exothermic phenomena, immediately after the battery is damaged even before temperature increase begins. The best TRR candidates are identified to be amines and alkanes. Among amines, secondary amines and tertiary amines perform better than primary amines. The reduction in electrolyte ionic conductivity and the displacement of electrolyte are the thermal-runaway-mitigation mechanisms of the secondary and the tertiary amines, respectively. Pentadecane is the best candidate among the alkanes under investigation, with the major working mechanism being electrolyte displacement. Impact tests on large pouch cells and high-energy battery chemistry were also performed; the results were quite encouraging.

Enrichment Mechanism of Semiconducting Single-walled Carbon Nanotubes by Surfactant Amines

Science.gov (United States)

Ju, Sang-Yong; Utz, Marcel; Papadimitrakopoulos, Fotios

2009-01-01

Utilization of single-walled carbon nanotubes (SWNTs) in high-end applications hinges on separating metallic (met-) from semiconducting (sem-) SWNTs. Surfactant amines, like octadecylamine (ODA) have proven instrumental for the selective extraction of sem-SWNTs from tetrahydrofuran (THF) nanotube suspensions. The chemical shift differences along the tail of an asymmetric, diacetylenic surfactant amine were used to probe the molecular dynamics in the presence and absence of nanotubes via NMR. The results suggest that the surfactant amine head is firmly immobilized onto the nanotube surface together with acidic water, while the aliphatic tail progressively gains larger mobility as it gets farther from the SWNT. X-ray and high-resolution TEM studies indicate that the sem-enriched sample is populated mainly by small nanotube bundles containing ca. three SWNTs. Molecular simulations in conjunction with previously determined HNO3/H2SO4 oxidation depths for met- and sem-SWNTs indicate that the strong pinning of the amine surfactants on the sem-enriched SWNTs bundles is a result of a well-ordered arrangement of nitrate/amine salts separated with a monomolecular layer of H2O. Such continuous 2D arrangement of nitrate/amine salts shields the local environment adjacent to sem-enriched SWNTs bundles and maintains an acidic pH that preserves nanotube oxidation (i.e. SWNTn+). This, in turn, results in strong interactions with charge-balancing NO3- counter ions that through their association with neutralized surfactant amines provide effective THF dispersion and consequent sem-enrichment. PMID:19397291

YCl3-Catalyzed Highly Selective Ring Opening of Epoxides by Amines at Room Temperature and under Solvent-Free Conditions

Directory of Open Access Journals (Sweden)

Wuttichai Natongchai

2017-11-01

Full Text Available A simple, efficient, and environmentally benign approach for the synthesis of β-amino alcohols is herein described. YCl3 efficiently carried out the ring opening of epoxides by amines to produce β-amino alcohols under solvent-free conditions at room temperature. This catalytic approach is very effective, with several aromatic and aliphatic oxiranes and amines. A mere 1 mol % concentration of YCl3 is enough to deliver β-amino alcohols in good to excellent yields with high regioselectivity.

Concentration, size distribution and dry deposition of amines in atmospheric particles of urban Guangzhou, China

Science.gov (United States)

Liu, Fengxian; Bi, Xinhui; Zhang, Guohua; Peng, Long; Lian, Xiufeng; Lu, Huiying; Fu, Yuzhen; Wang, Xinming; Peng, Ping'an; Sheng, Guoying

2017-12-01

Size-segregated PM10 samples were collected in Guangzhou, China during autumn of 2014. Nine amines, including seven aliphatic amines and two heterocyclic amines, were detected using a gas chromatography-mass spectrometer after derivatization by benzenesulfonyl chloride. The total concentration of the nine amines (Ʃamines) was 79.6-140.9 ng m-3 in PM10. The most abundant species was methylamine (MA), which had a concentration of 29.2-70.1 ng m-3. MA, dimethylamine (DMA), diethylamine (DEA) and dibutylamine (DBA) were the predominant amines in the samples and accounted for approximately 80% of Ʃamines in each size segment. Two heterocyclic amines, pyrrolidine (PYR) and morpholine (MOR), were detected in all samples and had average concentrations of 1.14 ± 0.37 and 1.89 ± 0.64 ng m-3, respectively, in particles with aerodynamic diameters ammonium ranged from 0.0068 to 0.0107 in particles with diameters <1.5 μm, and the maximum ratio occurred in the smallest particles (diameter< 0.49 μm). The average dry deposition flux and velocity of Ʃamines in PM10 were 7.9 ± 1.6 μg m-2 d-1 and 0.084 ± 0.0021 cm s-1, respectively. The results of this study provide essential information on the contribution of amines to secondary organic aerosols and dry removal mechanisms in urban areas.

Aqueous amine solution characterization for post-combustion CO_2 capture process

International Nuclear Information System (INIS)

El Hadri, Nabil; Quang, Dang Viet; Goetheer, Earl L.V.; Abu Zahra, Mohammad R.M.

2017-01-01

Highlights: • The CO_2 solubility of 30 aqueous amine solutions was measured at 30 wt% and 313.15 K. • The CO_2 loading of HMD is the highest, and that of TEA is the lowest. • 2DMAE, 3DMA1P, 1DMA2P, MDEA, TMPAD and 2EAE have a low heat of absorption with CO_2. • 2EAE can be used as an alternative to MEA in the CO_2 capture process. - Abstract: This article presents a thermodynamic and kinetic characterization of CO_2 absorption by 30 aqueous amine solutions. A solvent screening setup (S.S.S.) was used to find the CO_2 loading (α) for 30 different aqueous amine solutions (30 wt%) at a pressure of 1 bar with feed gas containing 15 vol% CO_2 and 85 vol% N_2 at 313.15 K to provide reliable absorber parameters. The structures of various amines (linear, non-linear, polyamines, sterically hindered, etc.) were tested and the S.S.S. results showed that hexamethylenediamine (HMD) has higher CO_2 loading at 1.35 moles of CO_2/mole of amine, and triethanolamine (TEA) has the lowest at 0.39 mole of CO_2/mole of amine. The heat of absorption indicates that MDEA has the lowest and HMD has the highest at −52.51 kJ/mole of CO_2 and −98.39 kJ/mole of CO_2, respectively. The combined data for the CO_2 loading and the absorption heat generated 6 amines that have good properties for the post-combustion CO_2 capture process in comparison with that of MEA. These amines are made up of one secondary amine (2-ethylaminoethanol, 2EAE) and 5 tertiary amines (N-methyldiethanolamine, MDEA, 1-dimethylamino-2-propanol, 1DMA2P, 2-dimethylaminoethanol, 2DMAE, 3-dimethylamino-1-propanol, 3DMA1P and N,N,N′,N′-tetramethyl-1,3-propanediamine, TMPDA). In comparison with the amine reference MEA (ΔH = −85.13 kJ/mole of CO_2 and α = 0.58 mole CO_2/mole of amine), the 6 amines have heats of absorption that are between −68.95 kJ/mole of CO_2 and −52.51 kJ/mole of CO_2, and their CO_2 loading is between 0.52 and 1.16 mole of CO_2/mole amine. The third important parameter, namely the

Fluorimetric determination of yttrium by methyl-bis(8-hydraxy--- 2-quinolyl)amine

International Nuclear Information System (INIS)

Golovina, A.P.; Kachin, S.V.; Runov, V.K.; Fakeeva, O.A.

1982-01-01

Using a method of mathematical Box-Wilson experiment planning the optimum conditions of yttrium fluorimetric determination by methyl-bis (8-hydroxy-2-quinolyl) amine (pH 7.5, csub(R)=1.4x10sup(-5) M) with the determination limit=0.05 μg/ml are found. An extraction-fluorimetric method of yttrium determination by methyl-bis (8-hydroxy-2-quinolyl) amine is developed. The extraction has been realized with aliphatic alcohols at pH > 11. The method is characteristic of the lowest determination limit (0.01 μg/ml) as compared with the known ones. The possibility is shown of yttrium determination in the presence of 5000-multiple aluminium contents, stoichiometric contents of La, Lu, Fe (3), U (6), tartrates, citrates

A study on the reactions of plant copper amine oxidase with C3 and C4 aliphatic diamines.

Science.gov (United States)

Sebela, M; Frébort, I; Lemr, K; Brauner, F; Pec, P

2000-12-01

The paper reports a study on the reactions of grass pea (Lathyrus sativus) amine oxidase (GPAO) with several aliphatic diamines. The influence of the chain length and of unsaturations in the molecules was examined. Kinetic measurements confirmed that trans-, i.e., (E)-2-butene-1,4-diamine (TDABE) and cis-, i.e., (Z)-2-butene-1,4-diamine (CDABE) could be classified as good substrates. Propane-1,3-diamine (DAP) and propene-1,3-diamine (DAPE) were only weakly oxidized, whereas 1,3-diamino-2-propanol (DAPL) was not utilized as a substrate. Contrary to the inactivator 2-butyne-1,4-diamine (DABI), DAPE was shown to be only a competitive inhibitor. DAP itself did not inhibit the catalytic activity. Irreversible inhibition of the activity occurred only after the incubation of GPAO with DABI; other diamines were without this effect. Differential pulse polarography and chromatofocusing confirmed that the aminoaldehyde product of DABI oxidation binds to the enzyme. Activity assay of pea aminoaldehyde dehydrogenase enabled us to detect the products of the oxidation of TDABE, CDABE, and DAP by GPAO. As the product of DAP oxidation, 3-amino-propanal (APAL) was detected by mass spectrometry and confirmed to be a potent noncompetitive inhibitor of GPAO. The absorption changes that occurred in the course of the reaction of GPAO with the diamines were investigated using rapid-scanning spectrophotometry. DABI, TDABE, CDABE, DAP, and DAPE reacted with GPAO providing characteristic maxima of the Cu(I)-semiquinolamine species that is formed in the catalytic cycle. The results presented here confirm that with the exception of DAPL, all the studied diamines could be classified as GPAO substrates, but only DABI can be considered as a mechanism-based inhibitor.

Studies of interaction of amines with TOPO/TOP capped CdSe quantum dots: Role of crystallite size and oxidation potential

International Nuclear Information System (INIS)

Sharma, Shailesh N.; Sharma, Himani; Singh, Gurmeet; Shivaprasad, S.M.

2008-01-01

This work reports the interaction of aliphatic (triethyl amine, butyl amine) and aromatic amines (PPD, aniline) with CdSe quantum dots of varied sizes. The emission properties and lifetime values of CdSe quantum dots were found to be dependent on the oxidation potential of amines and crystallite sizes. Smaller CdSe quantum dots (size ∼5 nm) ensure better surface coverage of amines and hence higher quenching efficiency of amines could be realized as compared to larger CdSe quantum dots (size ∼14 nm). Heterogeneous quenching of amines due to the presence of accessible and inaccessible set of CdSe fluorophores is indicated. PPD owing to its lowest oxidation potential (∼0.26 V) has been found to have higher quenching efficiency as compared to other amines TEA and aniline having oxidation potentials ∼0.66 and >1.0 V, respectively. Butyl amine on the other hand, plays a dual role: its post-addition acts as a quencher for smaller and enhances emission for larger CdSe quantum dots, respectively. The beneficial effect of butyl amine in enhancing emission intensity could be attributed to enhance capping effect and better passivation of surface-traps

Kinetic analysis of the reactivity of aliphatic cyclic alcohols and carboxylic acids in the T-for-H exchange reaction

International Nuclear Information System (INIS)

Tamura, Kiyoshi; Imaizumi, Hiroshi; Kano, Naoki

2007-01-01

In order to quantitatively evaluate the influence of tritium ( 3 He or T) on various functional groups in environment, the hydrogen isotope exchange reaction (T-for-H exchange reaction) between tritium-labeled poly-(vinyl alcohol) and each aliphatic cyclic alcohol (or carboxylic acid) has been dynamically observed in the range of 50 to 90degC. Consequently, the activities of the aliphatic cyclic alcohol and carboxylic acid increased with increasing reaction time. Applying in A''-McKay plot method to the observed data, the rate constants (k) for these materials were obtained. Using the k, the relation between the number of carbon atoms in the ring in each alcohol and the reactivity of the alcohol was quantitatively compared. Then, to clarify the effect of relative atomic charge of O atom (connected with the H atom in the hydroxy (or carboxy) group in the material) on the reactivity of the material, the MOPAC method was used. From both the above-mentioned and the obtained previously, the following nine items were found as to aliphatic cyclic alcohols (and carboxylic acids) in the T-for-H exchange reaction. (1) The reactivity of aliphatic cyclic alcohols (and carboxylic acids) depends on the temperature. (2) The reactivity of the cyclic materials decreases with increasing number of carbon atoms in the ring. (3) The reactivity of the aliphatic cyclic carboxylic acid seems to be smaller than that of aliphatic cyclic alcohol, and be larger than that of aliphatic cyclic amine. (4) For aliphatic cyclic alcohols, correlation exists between k and relative atomic charges of O atom obtained by the MOPAC method, but the tendency for aliphatic cyclic carboxylic acid is not clear. (5) As to having the same number of carbon atoms in each ring, the reactivity of the aliphatic cyclic carboxylic acid including the side chain is smaller than of the aliphatic cyclic carboxylic acid including no side chain. (6) The reactivity of aliphatic cyclic carboxylic acid is larger than that of

Dimethylzinc-Initiated Radical Coupling of β-Bromostyrenes with Ethers and Amines

DEFF Research Database (Denmark)

Sølvhøj, Amanda Birgitte; Ahlburg, Andreas; Madsen, Robert

2015-01-01

A new coupling reaction has been developed in which β-bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α-position. The transformation is mediated by Me2Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition-elimination mechanism. The ether...... and the amine are employed as solvent and the coupling takes place through the most stable α radical for unsymmetrical substrates. The products are obtained in moderate to good yields as the pure E isomers. The coupling can be achieved with a range of smaller cyclic and acyclic ethers/amines as well as various...

Devulcanization of Waste Tire Rubber Using Amine Based Solvents and Ultrasonic Energy

Directory of Open Access Journals (Sweden)

Walvekar Rashmi

2018-01-01

Full Text Available This research project focuses on an alternative pathway of devulcanizing waste tire rubber by using amine based chemicals. Waste tire rubbers are known to be as toxic, non-degradable material due to their vulcanized crosslink carbon structure, and disposing of such waste could impose hazardous impacts on the environment. The current rubber recycling methods that are practiced today are rather uneconomical, non-environmentally friendly, and also producing recycled rubber with low quality due to the alteration in the main polymeric chains of waste rubber. This project aims to answer the question of whether the usage of amine can produce high quality rubber, where the properties of recycled rubber is almost the same as new/virgin rubber. With known potential of amine, it is a challenge for the chemical to selectively cleave the sulfur bonds without affecting the main carbon backbone chain in the rubber structure and diminishing much of the rubber properties. To study this research, amine-treated rubber must undergo devulcanisation process by applying heat and sonication energy. Then, the properties of the amine-treated rubber were determined through a set of characterization tests and analysis which are: gel content test to determine the weight of rubber before and after devulcanization, the thermogravimetric analysis (TGA to determine the thermal degradation and stability of rubber, and Fourier Transform Infrared Spectroscopy (FTIR to determine any structural change of the rubber. In this research so far, the first two preliminary analysis tests have been performed. The gel content test has shown that tertiary amine samples possessed a lower gel content (% of (77 – 63 %, compared to primary amine samples (falls within the range of 80%, as well as the TGA test in which tertiary amine samples degrade faster than primary amine samples (suggesting a higher degree of rubber structure breakdown. For each type of amine, the concertation of amine did

Aliphatic Nucleophilic Radio-fluorination

International Nuclear Information System (INIS)

Roeda, D.; Dolle, F.

2010-01-01

In this review we are looking at some aspects of nucleophilic aliphatic radio-fluorination, notably the labelled fluoride source, design aspects, the leaving group and the solvent. It should be clear that there is more to this branch of radiolabelling than one would suspect from the frequently used standard tosylate replacement with kryptofix/[ 18 F]fluoride in acetonitrile or DMSO. Competitive elimination can be a serious problem that can affect both yield and purification. De-protection of sensitive groups after radiolabelling and its possible side reactions can complicate purification. The right choice of leaving group and protecting groups may be crucial. Newer developments such as the use of tertiary alcohols or ionic liquids as solvents, long-chain poly-fluorinated sulphonate leaving groups facilitating fluorous solid phase extraction, or immobilisation of the precursor on a solid phase support may help to solve these problems, for example the longstanding problems with [ 18 F]FLT, whereas older concepts such as certain cyclic reactive entities for ring opening or even an abandoned reagent as [ 18 F]DAST should not be forgotten. (authors)

Efficient and selective N-alkylation of amines with alcohols catalysed by manganese pincer complexes

Science.gov (United States)

Elangovan, Saravanakumar; Neumann, Jacob; Sortais, Jean-Baptiste; Junge, Kathrin; Darcel, Christophe; Beller, Matthias

2016-01-01

Borrowing hydrogen (or hydrogen autotransfer) reactions represent straightforward and sustainable C–N bond-forming processes. In general, precious metal-based catalysts are employed for this effective transformation. In recent years, the use of earth abundant and cheap non-noble metal catalysts for this process attracted considerable attention in the scientific community. Here we show that the selective N-alkylation of amines with alcohols can be catalysed by defined PNP manganese pincer complexes. A variety of substituted anilines are monoalkylated with different (hetero)aromatic and aliphatic alcohols even in the presence of other sensitive reducible functional groups. As a special highlight, we report the chemoselective monomethylation of primary amines using methanol under mild conditions. PMID:27708259

Tunable differentiation of tertiary C-H bonds in intramolecular transition metal-catalyzed nitrene transfer reactions.

Science.gov (United States)

Corbin, Joshua R; Schomaker, Jennifer M

2017-04-13

Metal-catalyzed nitrene transfer reactions are an appealing and efficient strategy for accessing tetrasubstituted amines through the direct amination of tertiary C-H bonds. Traditional catalysts for these reactions rely on substrate control to achieve site-selectivity in the C-H amination event; thus, tunability is challenging when competing C-H bonds have similar steric or electronic features. One consequence of this fact is that the impact of catalyst identity on the selectivity in the competitive amination of tertiary C-H bonds has not been well-explored, despite the potential for progress towards predictable and catalyst-controlled C-N bond formation. In this communication, we report investigations into tunable and site-selective nitrene transfers between tertiary C(sp 3 )-H bonds using a combination of transition metal catalysts, including complexes based on Ag, Mn, Rh and Ru. Particularly striking was the ability to reverse the selectivity of nitrene transfer by a simple change in the identity of the N-donor ligand supporting the Ag(i) complex. The combination of our Ag(i) catalysts with known Rh 2 (ii) complexes expands the scope of successful catalyst-controlled intramolecular nitrene transfer and represents a promising springboard for the future development of intermolecular C-H N-group transfer methods.

Liquid chromatographic separation and indirect detection of non-absorbing aliphatic compounds using m-nitrophenol as a detection agent

International Nuclear Information System (INIS)

Lee, Seung Seok; Kang, Sam Woo; Moon, Young Ja

1991-01-01

m-Nitrophenol(m-NP) was a detection agent for the use of the detection and separation of non-absorbing compounds such as aliphatic acids, alcohols, amines and tetraalkylammonium salts by indirect photometric detection in reversed-phase liquid chromatography. Response of samples was investigated to the several factors such as pH, temperature, and concentration of MeOH as well as concentration of detection reagent in mobile phase. The separation of several mixtures were attempted under optimum condition. (Author)

Biotransformation and bioactivation reactions of alicyclic amines in drug molecules.

Science.gov (United States)

Bolleddula, Jayaprakasam; DeMent, Kevin; Driscoll, James P; Worboys, Philip; Brassil, Patrick J; Bourdet, David L

2014-08-01

Aliphatic nitrogen heterocycles such as piperazine, piperidine, pyrrolidine, morpholine, aziridine, azetidine, and azepane are well known building blocks in drug design and important core structures in approved drug therapies. These core units have been targets for metabolic attack by P450s and other drug metabolizing enzymes such as aldehyde oxidase and monoamine oxidase (MAOs). The electron rich nitrogen and/or α-carbons are often major sites of metabolism of alicyclic amines. The most common biotransformations include N-oxidation, N-conjugation, oxidative N-dealkylation, ring oxidation, and ring opening. In some instances, the metabolic pathways generate electrophilic reactive intermediates and cause bioactivation. However, potential bioactivation related adverse events can be attenuated by structural modifications. Hence it is important to understand the biotransformation pathways to design stable drug candidates that are devoid of metabolic liabilities early in the discovery stage. The current review provides a comprehensive summary of biotransformation and bioactivation pathways of aliphatic nitrogen containing heterocycles and strategies to mitigate metabolic liabilities.

Manganese-catalysed benzylic C(sp3)-H amination for late-stage functionalization.

Science.gov (United States)

Clark, Joseph R; Feng, Kaibo; Sookezian, Anasheh; White, M Christina

2018-06-01

Reactions that directly install nitrogen into C-H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Although selective intramolecular C-H amination reactions are known, achieving high levels of reactivity while maintaining excellent site selectivity and functional-group tolerance remains a challenge for intermolecular C-H amination. Here, we report a manganese perchlorophthalocyanine catalyst [MnIII(ClPc)] for intermolecular benzylic C-H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site selectivity. In the presence of a Brønsted or Lewis acid, the [MnIII(ClPc)]-catalysed C-H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies suggest that C-H amination likely proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C-H cleavage is the rate-determining step of the reaction. Collectively, these mechanistic features contrast with previous base-metal-catalysed C-H aminations and provide new opportunities for tunable selectivities.

"Nanorust"-catalyzed benign oxidation of amines for selective synthesis of nitriles.

Science.gov (United States)

Jagadeesh, Rajenahally V; Junge, Henrik; Beller, Matthias

2015-01-01

Organic nitriles constitute key precursors and central intermediates in organic synthesis. In addition, nitriles represent a versatile motif found in numerous medicinally and biologically important compounds. Generally, these nitriles are synthesized by traditional cyanation procedures using toxic cyanides. Herein, we report the selective and environmentally benign oxidative conversion of primary amines for the synthesis of structurally diverse aromatic, aliphatic and heterocyclic nitriles using a reusable "nanorust" (nanoscale Fe2 O3 )-based catalysts applying molecular oxygen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and Properties of Some Novel Poly benzoxazine Containing Pendent Aliphatic Chains

International Nuclear Information System (INIS)

Agag, T.; Akelah, A.; Rehaband, A.; Mostafa, S.

2005-01-01

Poly benzoxazine as a newly developed type of phenolic resin has an excellent properties-process ability-price balance. Despite having the usual characteristics of the typical phenolic resins, such as heat resistance, good electronic properties and flame retardance, poly benzoxazine have additional advantageous characteristics superior to the typical phenolic. These characteristics include low melt viscosity of the monomers, no strong acid or basic catalysts needed for the polymerization, and no by-products evolved during the polymerization as well as near-zero shrinkage or expansion upon curing. However, the brittleness is considered the main disadvantage of this new class of thermoset, like all the conventional resins. In the current study, we have prepared a series of new monofunctional and bifunctional benzoxazine monomers from different long chain aliphatic amines, paraformaldehyde and various phenols, using solventless method. The structure of the novel monomers was confirmed by IR and 1H-NMR, indicating the presence of cyclic benzoxazine structure. The thermoset obtained by the thermal cure of benzoxazine monomers showed improved toughness with lower glass transition temperatures than the typical known types of poly benzoxazine due to the flexibilizing effect of the long aliphatic chains in the novel poly benzoxazine

Amine Functionalization via Oxidative Photoredox Catalysis: Methodology Development and Complex Molecule Synthesis

Science.gov (United States)

2016-01-01

Conspectus While the use of visible light to drive chemical reactivity is of high importance to the development of environmentally benign chemical transformations, the concomitant use of a stoichiometric electron donor or acceptor is often required to steer the desired redox behavior of these systems. The low-cost and ubiquity of tertiary amine bases has led to their widespread use as reductive additives in photoredox catalysis. Early use of trialkylamines in this context was focused on their role as reductive excited state quenchers of the photocatalyst, which in turn provides a more highly reducing catalytic intermediate. In this Account, we discuss some of the observations and thought processes that have led from our use of amines as reductive additives to their use as complex substrates and intermediates for natural product synthesis. Early attempts by our group to construct key carbon–carbon bonds via free-radical intermediates led to the observation that some trialkylamines readily behave as efficient hydrogen atom donors under redox-active photochemical conditions. In the wake of in-depth mechanistic studies published in the 1970s, 1980s and 1990s, this understanding has in turn allowed for a systematic approach to the design of a number of photochemical methodologies through rational tuning of the amine component. Minimization of the C–H donicity of the amine additive was found to promote desired C–C bond formation in a number of contexts, and subsequent elucidation of the amine’s redox fate has sparked a reevaluation of the amine’s role from that of reagent to that of substrate. The reactivity of tertiary amines in these photochemical systems is complex, and allows for a number of mechanistic possibilities that are not necessarily mutually exclusive. A variety of combinations of single-electron oxidation, C–H abstraction, deprotonation, and β-scission result in the formation of reactive intermediates such as α-amino radicals and iminium ions

Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials: Synthesis, nanostructure and properties

International Nuclear Information System (INIS)

Zulfiqar, Sonia; Ahmad, Zahoor; Ishaq, Muhammad; Sarwar, Muhammad Ilyas

2009-01-01

New type of aromatic-aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (T g ) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability.

Aromatic-aliphatic polyamide/montmorillonite clay nanocomposite materials: Synthesis, nanostructure and properties

Energy Technology Data Exchange (ETDEWEB)

Zulfiqar, Sonia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ahmad, Zahoor [Department of Chemistry, Faculty of Science, Kuwait University, P. O. Box: 5969, Safat 13060 (Kuwait); Ishaq, Muhammad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Sarwar, Muhammad Ilyas, E-mail: ilyassarwar@hotmail.com [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716 (United States)

2009-11-15

New type of aromatic-aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (T{sub g}) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability.

A practical and catalyst-free trifluoroethylation reaction of amines using trifluoroacetic acid

Science.gov (United States)

Andrews, Keith G.; Faizova, Radmila; Denton, Ross M.

2017-06-01

Amines are a fundamentally important class of biologically active compounds and the ability to manipulate their physicochemical properties through the introduction of fluorine is of paramount importance in medicinal chemistry. Current synthesis methods for the construction of fluorinated amines rely on air and moisture sensitive reagents that require special handling or harsh reductants that limit functionality. Here we report practical, catalyst-free, reductive trifluoroethylation reactions of free amines exhibiting remarkable functional group tolerance. The reactions proceed in conventional glassware without rigorous exclusion of either moisture or oxygen, and use trifluoroacetic acid as a stable and inexpensive fluorine source. The new methods provide access to a wide range of medicinally relevant functionalized tertiary β-fluoroalkylamine cores, either through direct trifluoroethylation of secondary amines or via a three-component coupling of primary amines, aldehydes and trifluoroacetic acid. A reduction of in situ-generated silyl ester species is proposed to account for the reductive selectivity observed.

Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

Science.gov (United States)

Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

2016-02-01

The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines. Copyright © 2015 Elsevier Inc. All rights reserved.

Highly Chemoselective Reduction of Amides (Primary, Secondary, Tertiary) to Alcohols using SmI2/Amine/H2O under Mild Conditions

Science.gov (United States)

2014-01-01

Highly chemoselective direct reduction of primary, secondary, and tertiary amides to alcohols using SmI2/amine/H2O is reported. The reaction proceeds with C–N bond cleavage in the carbinolamine intermediate, shows excellent functional group tolerance, and delivers the alcohol products in very high yields. The expected C–O cleavage products are not formed under the reaction conditions. The observed reactivity is opposite to the electrophilicity of polar carbonyl groups resulting from the nX → π*C=O (X = O, N) conjugation. Mechanistic studies suggest that coordination of Sm to the carbonyl and then to Lewis basic nitrogen in the tetrahedral intermediate facilitate electron transfer and control the selectivity of the C–N/C–O cleavage. Notably, the method provides direct access to acyl-type radicals from unactivated amides under mild electron transfer conditions. PMID:24460078

Radiolytic crosslinking and chain scission in aliphatic and alkyl-aromatic polyamides: Pt. 2

International Nuclear Information System (INIS)

Lyons, B.J.; Glover, L.C. Jr.

1991-01-01

Regression analysis of the radiation parameters of nine aliphatic polyamides exposed to ionizing radiation leads to the conclusion that the decline in the ratio of chain scission to crosslinking in higher aliphatic polyamides is best related to the linear increase in the methylene content of, or the number of methylene groups in, the polyamide repeat unit. G(crosslink)[G(X)] and G(chain scission) [G(CS)] values, however, do not correlate well with either of these parameters. Rather it is found that the major determinant of yields [about 80-85% of the variation for G(X), 70% for G(CS)] is the number of hydrogen atoms or methylene groups in the amine residue. Although, logically, the yields of crosslinks and chain scissions in polyamides would be expected to tend to that of polyethylene as the number of methylene groups in the repeat unit increases, use of two models assuming an exponential trend to the G(X) value characteristic of polyethylene in the analysis did not provide better fits to the data than the simple linear model referred to above. Indeed, the assumption of a significant exponential trend factor led to a marked drop in the goodness of fit. (author)

Ozone Promotes Chloropicrin Formation by Oxidizing Amines to Nitro Compounds.

Science.gov (United States)

McCurry, Daniel L; Quay, Amanda N; Mitch, William A

2016-02-02

Chloropicrin formation has been associated with ozonation followed by chlorination, but the reaction pathway and precursors have been poorly characterized. Experiments with methylamine demonstrated that ozonation converts methylamine to nitromethane at ∼100% yield. Subsequent chlorination converts nitromethane to chloropicrin at ∼50% yield under the conditions evaluated. Similarly high yields from other primary amines were limited to those with functional groups on the β-carbon (e.g., the carboxylic acid in glycine) that facilitate carbon-carbon bond cleavage to release nitromethyl anion. Secondary amines featuring these reactive primary amines as functional groups (e.g., secondary N-methylamines) formed chloropicrin at high yields, likely by facile dealkylation to release the primary nitro compound. Chloropicrin yields from tertiary amines were low. Natural water experiments, including derivatization to transform primary and secondary amines to less reactive carbamate functional groups, indicated that primary and secondary amines were the dominant chloropicrin precursors during ozonation/chlorination. Ozonation followed by chlorination of the primary amine side chain of lysine demonstrated low yields (∼0.2%) of chloropicrin, but high yields (∼17%) of dichloronitrolysine, a halonitroalkane structural analogue to chloropicrin. However, chloropicrin yields increased and dichloronitrolysine yields decreased in the absence of hydroxyl radical scavengers, suggesting that future research should characterize the potential occurrence of such halonitroalkane analogues relative to natural radical scavenger (e.g., carbonate) concentrations.

Metal-free oxidative olefination of primary amines with benzylic C-H bonds through direct deamination and C-H bond activation.

Science.gov (United States)

Gong, Liang; Xing, Li-Juan; Xu, Tong; Zhu, Xue-Ping; Zhou, Wen; Kang, Ning; Wang, Bin

2014-09-14

An oxidative olefination reaction between aliphatic primary amines and benzylic sp(3) C-H bonds has been achieved using N-bromosuccinimide as catalyst and tert-butyl hydroperoxide as oxidant. The olefination proceeds under mild metal-free conditions through direct deamination and benzylic C-H bond activation, and provides easy access to biologically active 2-styrylquinolines with (E)-configuration.

Tris{2-[(2-aminobenzylideneamino]ethyl}amine

Directory of Open Access Journals (Sweden)

Perla Elizondo Martínez

2010-12-01

Full Text Available The title Schiff base, C27H33N7, is a tripodal amine displaying C3 symmetry, with the central tertiary N atom lying on the threefold crystallographic axis. The N—CH2—CH2—N conformation of the pendant arms is gauche [torsion angle = 76.1 (3°], which results in a claw-like molecule, with the terminal aniline groups wrapped around the symmetry axis. The lone pair of the apical N atom is clearly oriented inwards towards the cavity, and should thus be chemically inactive. The amine NH2 substituents lie in the plane of the benzene ring to which they are bonded. With such an arrangement, one amine H atom forms an S(6 motif through a weak N—H...N hydrogen bond with the imine N atom, while the other is engaged in an intermolecular N—H...π contact involving the benzene ring of a neighbouring molecule related by inversion. The benzene rings also participate in an intramolecular C—H...π contact of similar strength. In the crystal structure, molecules are separated by empty voids (ca 5% of the crystal volume, although the crystal seems to be unsolvated.

Ionic liquids as silica deactivating agents in gas chromatography for direct analysis of primary amines in water.

Science.gov (United States)

Krzyżaniak, Agnieszka; Weggemans, Wilko; Schuur, Boelo; de Haan, André B

2011-12-16

Analysis of primary amines in aqueous samples remains a challenging analytical issue. The preferred approach by gas chromatography is hampered by interactions of free silanol groups with the highly reactive amine groups, resulting in inconsistent measurements. Here, we report a method for direct analysis of aliphatic amines and diamines in aqueous samples by gas chromatography (GC) with silanol deactivation using ionic liquids (ILs). ILs including trihexyl(tetradecyl)phosphonium bis 2,4,4-(trimethylpentyl)phosphinate (Cyphos IL-104), 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide [pmim][Tf(2)N] and N″-ethyl-N,N,N',N'-tetramethylguanidinium tris(pentafluoroethyl)trifluorophosphate [etmg][FAP] were tested as deactivating media for the GC liner. Solutions of these ILs in methanol were injected in the system prior to the analysis of primary amines. Butane-1,4-diamine (putrescine, BDA) was used as a reference amine. The best results were obtained using the imidazolium IL [pmim][Tf(2)N]. With this deactivator, excellent reproducibility of the analysis was achieved, and the detection limit of BDA was as low as 1mM. The applicability of the method was proven for the analysis of two different primary amines (C4-C5) and pentane-1,5-diamine. Copyright © 2011 Elsevier B.V. All rights reserved.

Photochemical reactions of triplet benzophenone and anthraquinone molecules with amines in the gas phase

International Nuclear Information System (INIS)

Zalesskaya, G.A.; Sambor, E.G.; Belyi, N.N.

2004-01-01

The intermolecular photoinduced reactions between triplet ketone molecules and aliphatic amines and pyridine are studied by the quenching of delayed fluorescence of anthraquinone and benzophenone vapors by diethylamine, dibutylamine, cyclohexylamine, triethylamine, and pyridine. In the temperature range 423-573 K, the delayed fluorescence quenching rate constants k q are estimated from changes in the decay rate constant and the intensity of delayed fluorescence upon increasing pressure of bath gases. It is ascertained that, in the gas phase, the mixtures under study exhibit both a negative and a positive dependence of k q on temperature, which indicates that some photoinduced reactions do not have activation barriers. The rate constant k q is shown to increase with decreasing ionization potential of the electron donors. This points to the importance of interactions with charge transfer in the photoreaction of triplet ketone molecules with aliphatic amines and pyridine in the gas phase. The relationship between k q and the change in the free energy ΔG upon the photoinduced intermolecular electron transfer, which is the primary stage of the photochemical reaction, is studied. It is shown that the dependence k q (ΔG) for the donor-acceptor pairs under study is described well by the Marcus equation, in which the average vibrational energies of the donor and acceptor are taken into account for the estimate of ΔG

Aliphatic alkenes and alkynes

International Nuclear Information System (INIS)

Cserep, Gy.

1981-01-01

This chapter describes the decomposition of aliphatic alkenes and alkynes by radiolysis, concentrating on results published after 1968. The radiolysis of individual compounds, product yields and possible mechanisms of radiation chemical reactions are discussed in detail. The radiolysis of mixtures of aliphatic alkenes is also investigated. General information on decomposition and some condensation reactions is also presented. (Auth./C.F.)

The effect of amine protonation on the electrical properties of spin-assembled single-walled carbon nanotube networks

Energy Technology Data Exchange (ETDEWEB)

Opatkiewicz, Justin P; LeMieux, Melburne C; Bao Zhenan [Department of Chemical Engineering, Stanford University, Stanford, CA 94305 (United States); Patil, Nishant P; Wei Hai; Mitra, Subhasish, E-mail: zbao@stanford.edu [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)

2011-03-25

Amine-terminated self-assembled monolayers (SAMs) have been shown to selectively adsorb semiconducting single-walled carbon nanotubes (sc-SWNTs). Previous studies have shown that when deposited by spin coating, the resulting nanotube networks (SWNTnts) can be strongly influenced by the charge state of the amine (primary, secondary, and tertiary). When the amine surfaces were exposed to varying pH solutions, the conductivity and overall quality of the resulting fabricated networks were altered. Atomic force microscopy (AFM) topography had shown that the density of the SWNTnts was reduced as the amine protonation decreased, indicating that the electrostatic attraction between the SWNTs in solution and the surface influenced the adsorption. Simultaneously, {mu}-Raman analysis had suggested that when exposed to more basic conditions, the resulting networks were enhanced with sc-SWNTs. To directly confirm this enhancement, Ti/Pd contacts were deposited and devices were tested in air. Key device characteristics were found to match the enhancement trends previously observed by spectroscopy. For the primary and secondary amines, on/off current ratios were commensurate with the Raman trends in metallic contribution, while no trends were observed on the tertiary amine (due to weaker interactions). Finally, differing SWNT solution volumes were used to compensate for adsorption differences and yielded identical SWNTnt densities on the various pH-treated samples to eliminate the influence of network density. These results further the understanding of the amine-SWNT interaction during the spin coating process. Overall, we provide a convenient route to provide SWNT-based TFTs with highly tunable electronic charge transport through better understanding of the influence of these specific interactions.

The effect of amine protonation on the electrical properties of spin-assembled single-walled carbon nanotube networks

International Nuclear Information System (INIS)

Opatkiewicz, Justin P; LeMieux, Melburne C; Bao Zhenan; Patil, Nishant P; Wei Hai; Mitra, Subhasish

2011-01-01

Amine-terminated self-assembled monolayers (SAMs) have been shown to selectively adsorb semiconducting single-walled carbon nanotubes (sc-SWNTs). Previous studies have shown that when deposited by spin coating, the resulting nanotube networks (SWNTnts) can be strongly influenced by the charge state of the amine (primary, secondary, and tertiary). When the amine surfaces were exposed to varying pH solutions, the conductivity and overall quality of the resulting fabricated networks were altered. Atomic force microscopy (AFM) topography had shown that the density of the SWNTnts was reduced as the amine protonation decreased, indicating that the electrostatic attraction between the SWNTs in solution and the surface influenced the adsorption. Simultaneously, μ-Raman analysis had suggested that when exposed to more basic conditions, the resulting networks were enhanced with sc-SWNTs. To directly confirm this enhancement, Ti/Pd contacts were deposited and devices were tested in air. Key device characteristics were found to match the enhancement trends previously observed by spectroscopy. For the primary and secondary amines, on/off current ratios were commensurate with the Raman trends in metallic contribution, while no trends were observed on the tertiary amine (due to weaker interactions). Finally, differing SWNT solution volumes were used to compensate for adsorption differences and yielded identical SWNTnt densities on the various pH-treated samples to eliminate the influence of network density. These results further the understanding of the amine-SWNT interaction during the spin coating process. Overall, we provide a convenient route to provide SWNT-based TFTs with highly tunable electronic charge transport through better understanding of the influence of these specific interactions.

Comparison of several solid-phase extraction sorbents for continuous determination of amines in water by gas chromatography-mass spectrometry.

Science.gov (United States)

Jurado-Sánchez, Beatriz; Ballesteros, Evaristo; Gallego, Mercedes

2009-08-15

A semiautomatic method has been proposed for the determination of different types of amines in water samples including anilines, chloroanilines, N-nitrosamines and aliphatic amines. The analytes were retained on a solid-phase extraction sorbent column and after elution, 1 microL of the extract was analysed by gas chromatography coupled with electron impact ionization mass spectrometry. A systematic overview is given of the advantages and disadvantages of several sorbents (LiChrolut EN, Oasis HLB, RP-C(18), graphitized carbon black, fullerenes and nanotubes) in the retention of amine compounds and based on sensitivity, selectivity and reliability. The retention efficiency for the studied amines was higher (ca. 100%) with LiChrolut EN and Oasis HLB than it was with RP-C(18) and fullerenes (53 and 62%, respectively, on average). Detection limits of 0.5-16 ng L(-1) for the 27 amines studied were obtained when using a sorbent column containing 75 mg of LiChrolut EN for 100mL of sample, the RSD being lower than 6.5%. The method was applied with good accuracy and precision in the determination of amines in various types of water including river, pond, tap, well, drinking, swimming pool and waste.

Quantification of amine functional groups and their influence on OM/OC in the IMPROVE network

Science.gov (United States)

Kamruzzaman, Mohammed; Takahama, Satoshi; Dillner, Ann M.

2018-01-01

Recently, we developed a method using FT-IR spectroscopy coupled with partial least squares (PLS) regression to measure the four most abundant organic functional groups, aliphatic C-H, alcohol OH, carboxylic acid OH and carbonyl C=O, in atmospheric particulate matter. These functional groups are summed to estimate organic matter (OM) while the carbon from the functional groups is summed to estimate organic carbon (OC). With this method, OM and OM/OC can be estimated for each sample rather than relying on one assumed value to convert OC measurements to OM. This study continues the development of the FT-IR and PLS method for estimating OM and OM/OC by including the amine functional group. Amines are ubiquitous in the atmosphere and come from motor vehicle exhaust, animal husbandry, biomass burning, and vegetation among other sources. In this study, calibration standards for amines are produced by aerosolizing individual amine compounds and collecting them on PTFE filters using an IMPROVE sampler, thereby mimicking the filter media and collection geometry of ambient standards. The moles of amine functional group on each standard and a narrow range of amine-specific wavenumbers in the FT-IR spectra (wavenumber range 1 550-1 500 cm-1) are used to develop a PLS calibration model. The PLS model is validated using three methods: prediction of a set of laboratory standards not included in the model, a peak height analysis and a PLS model with a broader wavenumber range. The model is then applied to the ambient samples collected throughout 2013 from 16 IMPROVE sites in the USA. Urban sites have higher amine concentrations than most rural sites, but amine functional groups account for a lower fraction of OM at urban sites. Amine concentrations, contributions to OM and seasonality vary by site and sample. Amine has a small impact on the annual average OM/OC for urban sites, but for some rural sites including amine in the OM/OC calculations increased OM/OC by 0.1 or more.

Thermodynamic functions of hydrogen bonding of amines in methanol derived from solution calorimetry data and headspace analysis

International Nuclear Information System (INIS)

Zaitseva, Ksenia V.; Varfolomeev, Mikhail A.; Solomonov, Boris N.

2012-01-01

Highlights: ► Solution enthalpies and activity coefficients of amines in methanol were measured. ► Thermodynamic functions of H-bonding of amines with methanol were determined. ► Specific interaction entropy of amines in methanol can be about zero or positive. ► Cooperativity of H-bonds in methanol media is smaller than in water solutions. ► A new view on analysis of specific interaction of solute with methanol is presented. - Abstract: Reactivity and equilibrium properties of organic molecules in self-associated liquids greatly depend on the hydrogen bonding with solvent. This work contains comprehensive thermodynamic analysis of hydrogen bonding of aliphatic and aromatic amines in self-associated solvent methanol. Enthalpies of solution at infinite dilution and limiting activity coefficients for the studied systems were measured experimentally. Enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol were determined. These values were found to be decreased compared with hydrogen bond energy in equimolar complexes “methanol–amine” determined in inert solvent or base media. A linear dependence between enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol was observed. It was firstly revealed that the entropy of specific interactions of amines with neat methanol can be about zero or positive. Disruption of solvent–solvent hydrogen bonds can be regarded as the most important step during dissolution of amine in methanol. It was found that the cooperative effect influences on the Gibbs energies of hydrogen bonding of amines in methanol, but in a lesser extent than in aqueous solutions. The new results show that the hydrogen bonding process in the self-associated solvents differs significantly from equimolar complexation in aprotic media.

Extraction and purification of plutonium by a tertiary amine; Extraction et purification du plutonium par une amine tertiaire

Energy Technology Data Exchange (ETDEWEB)

Trentinian, M de; Chesne, A [Commissariat a l' Energie Atomique, Fontenay aux Roses, Section de Chimie des Actimides (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Trilaurylamine diluted with a paraffinic solvent (dodecane) was studied as part of the research dealing with the separation and purification of plutonium. The physical properties (solubility of nitrates in the amine as a function of temperature) and the resistance to radiations of this substance were examined. The extraction characteristics of nitric solutions of plutonium, uranium and certain fission products are given as a function of the following factors: concentration of the various ions in solution, valency states. A method of plutonium purification based on these results is presented. (author) [French] La trilaurylamine diluee par un solvant paraffinique (dodecane) a ete etudiee dans le cadre des recherches concernant la separation et la purification du plutonium. Une etude des caracteres physiques (solubilite des nitrates dans l'amine en fonction de la temperature) s'ajoute a celle de la tenue aux radiations de ce corps. Les caracteristiques d'extraction de solutions nitriques de plutonium, uranium, et certains produits de fission, sont donnes en fonction des facteurs suivants: concentration des differents ions en solution, etats de valence. On presente une methode de purification du plutonium basee sur ces resultats. (auteur)

Chemical and Molecular Descriptors for the Reactivity of Amines with CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Lee, Anita S.; Kitchin, John R.

2012-10-24

Amine-based solvents are likely to play an important role in CO{sub 2} capture applications in the future, and the identification of amines with superior performance will facilitate their use in CO{sub 2} capture. While some improvements in performance will be achieved through process modifications, modifying the CO{sub 2} capture performance of an amine also implies in part an ability to modify the reactions between the amine and CO{sub 2} through development of new functionalized amines. We present a computational study of trends in the reactions between CO{sub 2} and functionalized amines with a focus on identifying molecular descriptors that determine trends in reactivity. We examine the formation of bicarbonate and carbamate species on three classes of functionalized amines: alkylamines, alkanolamines, and fluorinated alkylamines including primary, secondary and tertiary amines in each class. These functional groups span electron-withdrawing to donating behavior, hydrogen-bonding, extent of functionalization, and proximity effects of the functional groups. Electron withdrawing groups tend to destabilize CO{sub 2} reaction products, whereas electron-donating groups tend to stabilize CO{sub 2} reaction products. Hydrogen bonding stabilizes CO{sub 2} reaction products. Electronic structure descriptors based on electronegativity were found to describe trends in the bicarbonate formation energy. A chemical correlation was observed between the carbamate formation energy and the carbamic acid formation energy. The local softness on the reacting N in the amine was found to partially explain trends carbamic acid formation energy.

Thermodynamic functions of hydrogen bonding of amines in methanol derived from solution calorimetry data and headspace analysis

Energy Technology Data Exchange (ETDEWEB)

Zaitseva, Ksenia V., E-mail: zaitseva.ksenia@gmail.com [Chemical Institute, Kazan (Volga Region) Federal University, Kremlevskaya 18, Kazan 420008 (Russian Federation); Varfolomeev, Mikhail A., E-mail: vma.ksu@gmail.com [Chemical Institute, Kazan (Volga Region) Federal University, Kremlevskaya 18, Kazan 420008 (Russian Federation); Solomonov, Boris N., E-mail: boris.solomonov@ksu.ru [Chemical Institute, Kazan (Volga Region) Federal University, Kremlevskaya 18, Kazan 420008 (Russian Federation)

2012-05-10

Highlights: Black-Right-Pointing-Pointer Solution enthalpies and activity coefficients of amines in methanol were measured. Black-Right-Pointing-Pointer Thermodynamic functions of H-bonding of amines with methanol were determined. Black-Right-Pointing-Pointer Specific interaction entropy of amines in methanol can be about zero or positive. Black-Right-Pointing-Pointer Cooperativity of H-bonds in methanol media is smaller than in water solutions. Black-Right-Pointing-Pointer A new view on analysis of specific interaction of solute with methanol is presented. - Abstract: Reactivity and equilibrium properties of organic molecules in self-associated liquids greatly depend on the hydrogen bonding with solvent. This work contains comprehensive thermodynamic analysis of hydrogen bonding of aliphatic and aromatic amines in self-associated solvent methanol. Enthalpies of solution at infinite dilution and limiting activity coefficients for the studied systems were measured experimentally. Enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol were determined. These values were found to be decreased compared with hydrogen bond energy in equimolar complexes 'methanol-amine' determined in inert solvent or base media. A linear dependence between enthalpies and Gibbs energies of hydrogen bonding of amines with neat methanol was observed. It was firstly revealed that the entropy of specific interactions of amines with neat methanol can be about zero or positive. Disruption of solvent-solvent hydrogen bonds can be regarded as the most important step during dissolution of amine in methanol. It was found that the cooperative effect influences on the Gibbs energies of hydrogen bonding of amines in methanol, but in a lesser extent than in aqueous solutions. The new results show that the hydrogen bonding process in the self-associated solvents differs significantly from equimolar complexation in aprotic media.

Tris[2-(2H-indazol-2-ylethyl]amine

Directory of Open Access Journals (Sweden)

Saúl Ovalle

2012-06-01

Full Text Available The title tertiary amine, C27H27N7, a potential tripodal ligand for coordination chemistry, crystallizes with the central N atom located on a threefold axis of a trigonal cell. The gauche conformation of the N(amime—CH2—CH2—N(indazole chain [torsion angle = −64.2 (2°] places the pendant 2H-indazole heterocycles surrounding the symmetry axis, affording a claw-like shaped molecule. Two symmetry-related indazole planes in the molecule make an acute angle of 60.39 (4°. The lone pair of the tertiary N atom is located inside the cavity, and should thus be inactive (as a ligand. In the crystal, neither significant π–π nor C—H...π interactions between molecules are found.

Structural Influence on Excited State Dynamics in Simple Amines

DEFF Research Database (Denmark)

Klein, Liv Bærenholdt

experiments with calculations, provides new insight into the nature of the internal conversion processes that mediate the dynamical evolution between Rydberg states, and how structural variations in simple amine system have a large impact on the non-adiabatic processes. The experimental method of choice...... is femtosecond time-resolved photoelectron velocity map imaging (VMI), which is a newtechnique in the Copenhagen lab. The design, building and implementation of the VMI spectrometer has been a very substantial part of the thesis work. This techniques oers enhanced information content in the form of ecient...... and sensitive collection of photoelectron spectra. In particular, the angleresolved data available from the VMI approach provides highly detailed mechanistic insight about the relaxation pathways. One striking novel nding is that for tertiary amines, the critical factor driving the non-adiabatic dynamics...

RECOVERY OF CARBOXYLIC ACIDS FROM AQUEOUS SOLUTIONS BY LIQUID-LIQUID EXTRACTION WITH A TRIISOOCTYLAMINE DILUENT SYSTEM

Directory of Open Access Journals (Sweden)

G. Malmary

2001-12-01

Full Text Available Tertiary alkylamines in solution with organic diluents are attractive extractants for the recovery of carboxylic acids from dilute aqueous phases. The aim of this study was to investigate the mechanism for extraction of organic acids from water by a long-chain aliphatic tertiary amine. In order to attain this objective, we studied the liquid-liquid equilibria between the triisooctylamine + 1-octanol + n-heptane system as solvent and an aqueous solution of an individual carboxylic acid such as citric, lactic and malic acids. The experiments showed that the partition coefficient for a particular organic acid depends on the kind of solute, notably when the acid concentration in the aqueous phase is low. A mathematical model, where both chemical association and physical distribution are taken into consideration, is proposed. The model suggests that the various complexes obtained between amine and organic acids contribute to the distribution of the solute between the coexisting phases in equilibrium.

Aliphatic isocyanurates and polyisocyanurate networks

OpenAIRE

Driest, P. J.; Lenzi, V.; Marques, L.; Ramos, M. M. D.; Dijkstra, D. J.; Richter, F. U.; Stamatialis, D.; Grijpma, D. W.

2017-01-01

The production, processing, and application of aliphatic isocyanate (NCO)-based thermosets such as polyurethane coatings and adhesives are generally limited by the surprisingly high viscosity of tri-functionality and higher-functionality isocyanurates. These compounds are essential crosslinking additives for network formation. However, the mechanism by which these high viscosities are caused is not yet understood. In this work, model aliphatic isocyanurates were synthesized and isolated in hi...

N-hydroxysuccinimide-mediated photoelectrooxidation of aliphatic alcohols based on cadmium telluride nanoparticles decorated graphene nanosheets

International Nuclear Information System (INIS)

Navaee, Aso; Salimi, Abdollah

2013-01-01

A simple nonenzymatic electrochemical protocol is proposed for the oxidation of aliphatic alcohols using formed N-hydroxysuccinimide (NHS) radical cation on the graphene nanosheets/L-cysteine/cadmium telluride quantum dot (QD) nanocomposite (GNs/Cys/CdTe) modified glassy carbon (GC) electrode. At first, graphene oxide (GO) is chemically synthesized from graphite after which Cys is covalently functionalized to GO through formation of amide bonds between carboxylic acid groups of GO and amine groups of Cys. The resulting GNs/Cys is used as a capping agent to synthesize CdTe QD nanoparticles. After the characterization of the as-made nanocomposite which confirmed the successful attachment of CdTe nanoparticles to the GNs, the ability of the GNs/Cys/CdTe modified GC electrode toward the nonenzymatic ethanol electrooxidation is examined in the presence of NHS as an effective mediating system. Our results revealed that the proposed system possess a good activity to NHS electrooxidation and subsequently, ethanol oxidation. Moreover, the GNs/Cys/CdTe modified electrode displayed a significant photoelectrocatalytic activity toward the ethanol oxidation upon illumination by visible light. The photoactive GNs/Cys/CdTe nanohybrid presented here showing favorable photoelectrochemical features for nonenzymatic aliphatic alcohols oxidation may hold great promise to the development of electrochemical sensors and biofuel cells

Reaction constants, in cyclohexane, of lauryl-amines with tetrabromo-phenolphthalein magenta E acid

International Nuclear Information System (INIS)

Perez, J.J.

1966-11-01

Trilauryl amine is an extracting agent used for plutonium purification. Its main degradation product is di-laurylamine. The titration of this impurity is carried out by spectro-colorimetry in cyclohexane using bromophtalein Magenta E as coloured acid indicator. The reported dissociation constants for alcoylammonium salts are too closed to lead to a discrimination between secondary and tertiary amines. The present spectrophotometric study shows that the ratios of various dissociation constants for bromophtalein Magenta E salts are notably different from those for salts of simple coloured acids like 2,4 dinitro phenol. The structural changes accompanying the colorations are discussed in order to explain this phenomenon. (author) [fr

Supported polytertiary amines: highly efficient and selective SO2 adsorbents.

Science.gov (United States)

Tailor, Ritesh; Abboud, Mohamed; Sayari, Abdelhamid

2014-01-01

Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.

Cheminformatics Modeling of Amine Solutions for Assessing their CO2 Absorption Properties.

Science.gov (United States)

Kuenemann, Melaine A; Fourches, Denis

2017-07-01

As stricter regulations on CO 2 emissions are adopted worldwide, identifying efficient chemical processes to capture and recycle CO 2 is of critical importance for industry. The most common process known as amine scrubbing suffers from the lack of available amine solutions capable of capturing CO 2 efficiently. Tertiary amines characterized by low heats of reaction are considered good candidates but their absorption properties can significantly differ from one analogue to another despite high structural similarity. Herein, after collecting and curating experimental data from the literature, we have built a modeling set of 41 amine structures with their absorption properties. Then we analyzed their chemical composition using molecular descriptors and non-supervised clustering. Furthermore, we developed a series of quantitative structure-property relationships (QSPR) to assess amines' CO 2 absorption properties from their structural characteristics. These models afforded reasonable prediction performances (e. g., Q 2 LOO =0.63 for CO 2 absorption amount) even though they are solely based on 2D chemical descriptors and individual machine learning techniques (random forest and neural network). Overall, we believe the chemical analysis and the series of QSPR models presented in this proof-of-concept study represent new knowledge and innovative tools that could be very useful for screening and prioritizing hypothetical amines to be synthesized and tested experimentally for their CO 2 absorption properties. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidation of primary amines to oximes with molecular oxygen using 1,1-diphenyl-2-picrylhydrazyl and WO3/Al2O3 as catalysts.

Science.gov (United States)

Suzuki, Ken; Watanabe, Tomonari; Murahashi, Shun-Ichi

2013-03-15

The oxidative transformation of primary amines to their corresponding oximes proceeds with high efficiency under molecular oxygen diluted with molecular nitrogen (O2/N2 = 7/93 v/v, 5 MPa) in the presence of the catalysts 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungusten oxide/alumina (WO3/Al2O3). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various alicyclic amines and aliphatic amines can be converted to their corresponding oximes in excellent yields. It is noteworthy that the oxidative transformation of primary amines proceeds chemoselectively in the presence of other functional groups. The key step of the present oxidation is a fast electron transfer from the primary amine to DPPH followed by proton transfer to give the α-aminoalkyl radical intermediate, which undergoes reaction with molecular oxygen and hydrogen abstraction to give α-aminoalkyl hydroperoxide. Subsequent reaction of the peroxide with WO3/Al2O3 gives oximes. The aerobic oxidation of secondary amines gives the corresponding nitrones. Aerobic oxidative transformation of cyclohexylamines to cyclohexanone oximes is important as a method for industrial production of ε-caprolactam, a raw material for Nylon 6.

Mechanism of the extraction of nitric acid and water by organic solutions of tertiary alkyl-amines

International Nuclear Information System (INIS)

Gourisse, D.

1966-06-01

The micellar aggregation of tri-alkyl-ammonium nitrates in low polarity organic solvents has been verified by viscosity, conductivity and sedimentation velocity measurements. The aggregation depends upon the polarity of solvent, the length of the alkyl radicals and the organic concentration of the various constituents (tri-alkyl-ammonium nitrate, tri-alkyl-amine, nitric acid, water). The amine salification law has been established and the excess nitric acid and water solubilities in the organic solutions have been measured. Nitric acid and water are slightly more soluble in micellar organic solutions than in molecular organic solutions. A description of excess nitric acid containing tri-alkyl-ammonium nitrate solutions is proposed. (author) [fr

40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aliphatic polycarboxylic acid metal... Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical... as an aliphatic polycarboxylic acid metal salt (PMN P-01-7) is subject to reporting under this...

Gold recovery from acidic leach solutions using as extractants trialkylamines of N,N'-di-alkyl-aliphatic amides

Energy Technology Data Exchange (ETDEWEB)

Baroncelli, F.; Carlini, D.; Gasparini, G.M.; Simonetti, E.

1988-07-01

TriOctylAmine (TOA) and a di-substituted aliphatic amide, N,N-Di-N-ButylOctanamide (DBOA), were examined in batch and in mini mixer-settler experiments using leachates of Peruvian and Bolivian concentrates. With these minerals, very rich in sulfur (pyrites, stybine), 90-95% gold recovery in 12-24 hours was reached by leaching with 4M aqua regia (HCl 3M nitric acid 1M) at room temperature and with 1/3 solid/liquid ratio. With these leachate solutions (2-3M total acidity, 10-60 ppm ao Au), the two processes with TOA (GAMEX PROCESS) and with DBOA (AUMIDEX PROCESS) were tested and compared. Experimental results strongly support the possibility of using TOA and DBOA on an industrial scale.

Bioconversion of Airborne Methylamine by Immobilized Recombinant Amine Oxidase from the Thermotolerant Yeast Hansenula polymorpha

Directory of Open Access Journals (Sweden)

Sasi Sigawi

2014-01-01

Full Text Available Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health. The primary amine oxidase (primary amine : oxygen oxidoreductase (deaminating or amine oxidase, AMO; EC 1.4.3.21, a copper-containing enzyme from the thermotolerant yeast Hansenula polymorpha which was overexpressed in baker’s yeast Saccharomyces cerevisiae, was tested for its ability to oxidize airborne methylamine. A continuous fluidized bed bioreactor (CFBR was designed to enable bioconversion of airborne methylamine by AMO immobilized in calcium alginate (CA beads. The results demonstrated that the bioreactor with immobilized AMO eliminates nearly 97% of the airborne methylamine. However, the enzymatic activity of AMO causes formation of formaldehyde. A two-step bioconversion process was therefore proposed. In the first step, airborne methylamine was fed into a CFBR which contained immobilized AMO. In the second step, the gas flow was passed through another CFBR, with alcohol oxidase from the yeast H. polymorpha immobilized in CA, in order to decompose the formaldehyde formed in the first step. The proposed system provided almost total elimination of the airborne methylamine and the formaldehyde.

Iridium-Catalyzed Condensation of Primary Amines To Form Secondary Amines

DEFF Research Database (Denmark)

Lorentz-Petersen, Linda Luise Reeh; Jensen, Paw; Madsen, Robert

2009-01-01

Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields.......Symmetric secondary amines are readily obtained by heating a neat primary amine with 0.5 mol% of bis(dichloro[eta(5)-pentamethylcyclopentadienyl]iridium). The products are isolated by direct distillation in good yields....

Reaction of acid esters of methylenebis(phosphonous acid) with carbonyl compounds

International Nuclear Information System (INIS)

Novikova, Z.S.; Odinets, I.L.; Lutsenko, I.F.

1987-01-01

The reaction of methylenebis(phosphonites) containing two hydrophosphoryl groupings with aliphatic and aromatic aldehydes and ketones in the presence of alkali metal fluorides leads to methylenebis(α-hydroxyalkylphosphinates). The reaction of methylenebis(phosphonites) containing one hydrophosphoryl groupings with carbonyl compounds in the presence of alkali metal fluorides proceeds with the formation of a new type of heterocyclic phosphorus compound, viz., 1,2λ 3 ,4λ 5 -oxadiphospholanes. The reaction of acid esters of methylenebis(phosphonous) acid with carbonyl compounds in the presence of alkali metal alkoxides or a tertiary amine is accompanied by phosphinate-phosphonate rearrangement of the intermediately formed α-hydroxylalkylphosphinates

Shear bond strength of a self‑etched resin cement to an indirect ...

African Journals Online (AJOL)

2014-11-15

Nov 15, 2014 ... 3M ESPE, St. Paul, MN, USA Silane treated glass powder, substituted dimethacrylate 1‑benzyl‑5‑phenyl‑barbic‑acid, calcium salt, silane treated silica, sodium p‑toluenesulfinate, 1,12‑dodecane dimethycrylate calcium hydroxide methacrylated aliphatic amine methacrylated aliphatic amine titanium dioxide.

Structure, thermal and fracture mechanical properties of benzoxazine-modified amine-cured DGEBA epoxy resins

Directory of Open Access Journals (Sweden)

2011-03-01

Full Text Available First, traditional diamine hardeners of epoxy resins (EP were checked as potential accelerators for the benzoxazine (BOX homopolymerization. It was established that the acceleration effect depends on both the type and amount of the diamine compounds. In the follow-up work amine-curable diglycidyl ether bisphenol A (DGEBA type EP was modified with BOX keeping the EP/BOX ratio constant (75/25 wt.%. The amine hardeners, added in the EP in stoichiometric amounts, were of aliphatic and aromatic nature, viz. diethylenetriamine (DETA, 4,4'-diaminodiphenyl methane (DDM, and their 1/1 mixture. The thermal, viscoelastic, flexural and fracture mechanical properties of the EP/BOX hybrids were determined and compared to those of the reference EPs. Based on dynamic-mechanical thermal analysis and atomic force microscopy the formation of co-network between EP and BOX was concluded. Homopolymerized BOX was built in the network in nanoscaled inclusions and it was associated with internal antiplasticization. Incorporation of BOX improved the charring, enhanced the flexural modulus and strength, and reduced the glass transition of the parent EP. The fracture toughness and energy were not improved by hybridization with BOX.

Simultaneous analysis of fourteen tertiary amine stimulants in human urine for doping control purposes by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry

International Nuclear Information System (INIS)

Lu Jianghai; Wang San; Dong Ying; Wang Xiaobing; Yang Shuming; Zhang Jianli; Deng Jing; Qin Yang; Xu Youxuan; Wu Moutian; Ouyang Gangfeng

2010-01-01

A method for the simultaneous screening and confirmation of the presence of fourteen tertiary amine stimulants in human urine by gas chromatography-mass spectrometry (GC-MS) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed and validated. Solid phase extraction (SPE) and liquid-liquid extraction (LLE) approaches were utilized for the pre-treatment of the urine samples. The study indicated that the capillary temperature played a significant role in the signal abundances of the protonated molecules of cropropamide and crotethamide under positive ion electrospray ionization (ESI) conditions. In addition, comparison studies of two different pre-treatment approaches as well as the two ionization modes were conducted. The LODs of the developed method for all the analytes were lower than the minimum required performance limit (MRPL) as set forth in the World Anti-Doping Agency (WADA) technical document for laboratories. The human urine sample obtained after oral administration of prolintane.HCl was successfully analyzed by the developed method, which demonstrated the applicability and reliability of the method for routine doping control analysis.

A Mild and Green Route for Regio-selective Amination of Oxiranes Using Nanomagnetic Supported Ferrous Ion as a Solid Lewis Acid Catalyst in Water

Directory of Open Access Journals (Sweden)

Fariborz Mansouri

2016-07-01

Full Text Available A mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of Mn(II, Fe(II, Co(II, Ni(II, Cu(II and Zn(II cations onto the surface of hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp. Among six magnetically recoverable catalytic systems denoted as [γ-Fe2O3@HAp-MII], the catalyst in which M designated as Fe(II showed the best efficiency as well as regio-selectivity in amination of oxiranes under an ambient reaction condition. A wide variety of aromatic and aliphatic amines were reacted with epoxides using magnetically separable iron catalyst to give the corresponding amino alcohols in excellent yields and selectivities in water as solvent at room temperature. In addition, recovery of the catalyst was successfully carried out in subsequent runs without any decrease in activity even after 5 runs. High regio-selectivity toward terminal ring-opening, efficient catalyst reusability using simple magnetic separation, high yields, simplicity in operation and diversity for various substrates are of advantages of this study.

Modulation of the genotoxicity of bleomycin by amines through noncovalent DNA interactions and alteration of physiological conditions in yeast

International Nuclear Information System (INIS)

Hoffmann, George R.; Gessner, Gabrielle S.; Hughes, Jennifer F.; Ronan, Matthew V.; Sylvia, Katelyn E.; Willett, Christine J.

2007-01-01

The effects of amines on the induction of mitotic gene conversion by bleomycin (BLM) were studied at the trp5 locus in Saccharomyces cerevisiae strain D7. BLM induces double-strand breaks in DNA and is a potent recombinagen in this assay. The polyamine spermidine causes concentration-dependent protection against the genotoxicity of BLM, reducing the convertant frequency by over 90% under the most protective conditions. Spermine, diethylenetriamine, ethylenediamine, putrescine, and ethylamine were also antigenotoxic in combined treatments with BLM. There was a general correspondence between the protective effect and the number of amino groups, suggesting that more strongly cationic amines tend to be stronger antirecombinagens. Electrostatic association of the amines with DNA probably hinders BLM access to the 4' position of deoxyribose where it generates a free radical. Other amines interact with BLM differently from these unbranched aliphatic amines. The aminothiol cysteamine inhibits the genotoxicity of BLM under hypoxic conditions but increases it under euoxic conditions. In contrast, pargyline potentiates the genotoxicity of BLM under hypoxic conditions but not under euoxic conditions. The antirecombinagenic effect of cysteamine apparently involves DNA binding and depletion of oxygen needed for BLM activity, whereas its potentiation of BLM entails its serving as an electron source for the activation of BLM. Pargyline may enhance BLM indirectly by preventing the depletion of oxygen by monoamine and polyamine oxidase. The planar 9-aminoacridine weakly induces gene conversion in strain D7, but it is strongly synergistic with BLM. Enhancement of BLM activity by this compound and by the related nitroacridine Entozon is apparently mediated by intercalation of the acridine ring system into DNA. Thus, the influence of amines on the genotoxicity of BLM in yeast encompasses antigenotoxic, potentiating, and synergistic interactions. The underlying mechanisms involve

Modulation of the genotoxicity of bleomycin by amines through noncovalent DNA interactions and alteration of physiological conditions in yeast

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, George R. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)], E-mail: ghoffmann@holycross.edu; Gessner, Gabrielle S.; Hughes, Jennifer F.; Ronan, Matthew V.; Sylvia, Katelyn E.; Willett, Christine J. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)

2007-10-01

The effects of amines on the induction of mitotic gene conversion by bleomycin (BLM) were studied at the trp5 locus in Saccharomyces cerevisiae strain D7. BLM induces double-strand breaks in DNA and is a potent recombinagen in this assay. The polyamine spermidine causes concentration-dependent protection against the genotoxicity of BLM, reducing the convertant frequency by over 90% under the most protective conditions. Spermine, diethylenetriamine, ethylenediamine, putrescine, and ethylamine were also antigenotoxic in combined treatments with BLM. There was a general correspondence between the protective effect and the number of amino groups, suggesting that more strongly cationic amines tend to be stronger antirecombinagens. Electrostatic association of the amines with DNA probably hinders BLM access to the 4' position of deoxyribose where it generates a free radical. Other amines interact with BLM differently from these unbranched aliphatic amines. The aminothiol cysteamine inhibits the genotoxicity of BLM under hypoxic conditions but increases it under euoxic conditions. In contrast, pargyline potentiates the genotoxicity of BLM under hypoxic conditions but not under euoxic conditions. The antirecombinagenic effect of cysteamine apparently involves DNA binding and depletion of oxygen needed for BLM activity, whereas its potentiation of BLM entails its serving as an electron source for the activation of BLM. Pargyline may enhance BLM indirectly by preventing the depletion of oxygen by monoamine and polyamine oxidase. The planar 9-aminoacridine weakly induces gene conversion in strain D7, but it is strongly synergistic with BLM. Enhancement of BLM activity by this compound and by the related nitroacridine Entozon is apparently mediated by intercalation of the acridine ring system into DNA. Thus, the influence of amines on the genotoxicity of BLM in yeast encompasses antigenotoxic, potentiating, and synergistic interactions. The underlying mechanisms involve

Automated determination of aliphatic primary amines in wastewater by simultaneous derivatization and headspace solid-phase microextraction followed by gas chromatography-tandem mass spectrometry.

Science.gov (United States)

Llop, Anna; Pocurull, Eva; Borrull, Francesc

2010-01-22

This paper presents a fully automated method for determining ten primary amines in wastewater at ng/L levels. The method is based on simultaneous derivatization with pentafluorobenzaldehyde (PFBAY) and headspace solid-phase microextraction (HS-SPME) followed by gas chromatography coupled to ion trap tandem mass spectrometry (GC-IT-MS-MS). The influence of main factors on the efficiency of derivatization and of HS-SPME is described in detail and optimized by a central composite design. For all species, the highest enrichment factors were achieved using a 85 microm polyacrylate (PA) fiber exposed in the headspace of stirred water samples (750 rpm) at pH 12, containing 360 g/L of NaCl, at 40 degrees C for 15 min. Under optimized conditions, the proposed method achieved detection limits ranging from 10 to 100 ng/L (except for cyclohexylamine). The optimized method was then used to determine the presence of primary amines in various types of wastewater samples, such as influent and effluent wastewater from municipal and industrial wastewater treatment plants (WWTPs) and a potable water treatment plant. Although the analysis of these samples revealed the presence of up to 1500 microg/L of certain primary amines in influent industrial wastewater, the concentration of these compounds in the effluent and in municipal and potable water was substantially lower, at low microg/L levels. The new derivatization-HS-SPME-GC-IT-MS-MS method is suitable for the fast, reliable and inexpensive determination of primary amines in wastewater in an automated procedure. Copyright 2009 Elsevier B.V. All rights reserved.

Monomer-to-polymer conversion and micro-tensile bond strength to dentine of experimental and commercial adhesives containing diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide or a camphorquinone/amine photo-initiator system.

Science.gov (United States)

Miletic, Vesna; Pongprueksa, Pong; De Munck, Jan; Brooks, Neil R; Van Meerbeek, Bart

2013-10-01

To compare the degree of conversion (DC) of adhesives initiated by diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) or a camphorquinone/tertiary amine system (CQ/Amine) as well as their 'immediate' micro-tensile bond strength (μTBS) to bur-cut dentine. DC of Scotchbond Universal ('SBU'; 3M ESPE), its experimental counterpart containing TPO as photo-initiator system, an experimental G-aenial Bond ('Ga-B'; GC) adhesive formulation, and an experimental LUB-102 adhesive formulation ('LUB', Kuraray Noritake), containing as photo-initiatior system either 2wt% CQ along with 2wt% tertiary amine ('SBU_CQ/Amine'; 'Ga-B_CQ/Amine'; 'LUB_CQ/Amine'), or 2wt% TPO ('SBU_TPO'; 'Ga-B_TPO'; 'LUB_TPO'), was determined using Fourier-transform infrared spectroscopy (FTIR), after being cured with a dual-wavelength light-curing unit (bluephase 20i, Ivoclar Vivadent). The same adhesive formulations were applied to bur-cut mid-coronal dentine of intact human molars, and subjected to a μTBS test after 1-week water storage. Besides being applied following a self-etch (SE) application mode, the adhesive formulations SBU_CQ/Amine and SBU_TPO were also applied following an etch-and-rinse (E&R) mode, this both for DS and μTBS measurement. No significant difference in DC was found for any of the adhesive formulations, except for SBU_CQ/Amine_SE and SBU_TPO_SE. For both SBU formulations, a significantly higher DC was reached for the E&R than the SE approach. Regarding μTBS, no significant differences were recorded, except for the significantly higher μTBS measured for SBU_CQ/Amine_E&R and SBU_TPO_E&R. In self-etch adhesives, the photo-initiator TPO may be used instead of CQ/Amine. The curing and 'immediate' bonding efficiency depended on the application protocol (E&R versus SE), but not on the photo-initiator system. The photo-initiator TPO may be used in self-etch adhesives instead of CQ/Amine with similar curing and 'immediate' bonding efficiency. Copyright © 2013 Elsevier Ltd. All

Theoretical investigation of some high-performance novel amine azide propellants

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Debasis [Computational Fluid Dynamics Research Corp., Huntsville, AL 35805 (United States); Raman, Sumathi [Department of Chemistry, Oakwood College, 2000 Adventist Blvd., Huntsville, AL 35896 (United States)

2007-08-15

Monomethylhydrazine (MMH) is currently the most widely used hypergolic propellant, due to its high performance and low ignition delay. However, its toxicity is a major concern. The present work aims at developing high-performance hypergolic fuels that are based on tertiary amine azide functionality. A number of potential amine azide candidates have been proposed, and some of their physical and chemical properties have been computed using state-of-the-art molecular modeling techniques. Gas-phase heats of formation have been calculated using the CBS-QB3 method, and the first-principle COSMO-RS method has been used to compute heats of vaporization and vapor pressures. A density correlation, based on molecular-volume calculation, has been established to predict the densities of the candidate molecules. Finally, the liquid-phase heats of formation and densities have been used to predict the specific and density impulses of the proposed candidate molecules. The results show that many of the molecules proposed here have much higher density impulse than that of MMH, and may be considered for experimental studies. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

STUDIES ON RADICAL POLYMERIZATION OF METHYL METHACRYLATE INITIATED WITH ORGANIC PEROXIDE-AMINE SYSTEMS

Institute of Scientific and Technical Information of China (English)

QIU Kunyuan; SHUI Li; FENG Xinde

1984-01-01

Radical polymerization of methyl methacrylate (MMA) initiated with various diacyl peroxideamine systems was studied. Benzoyl peroxide (BPO) and lauroyl peroxide (LPO) were used as diacyl peroxide component, N,N-dimethyl aniline (DMA) and its para substituted derivatives, i.e., N,N-dimethyl-p-toluidine (DMT), p-hydroxymethyl-N,N-dimethyl aniline (HDMA), p-nitro-N,N-dimethyl aniline (NDMA) and p-dimethylamino benzaldehyde (DMAB) were used as amine components. It was found that the peroxide-DMT systems give higher rates of bulk polymerization Rp of MMA than the organic hydroperoxide-DMT systems with the following descending order BPO-DMT＞LPO-DMT＞CHP (cumene hydroperoxide)-DMT＞TBH (tert-butyl hydroperoxide)-DMT.The aromatic tertiary amines possess obvious structural effect on the Rp values in the diacyl peroxideamine system. The overall activation energy of MMA polymerization was determined and the kinetics of polymerization of MMA initiated with BPO-DMT system was investigated.

Aliphatic alcohols in spirits inhibit phagocytosis by human monocytes.

Science.gov (United States)

Pál, László; Árnyas, Ervin M; Bujdosó, Orsolya; Baranyi, Gergő; Rácz, Gábor; Ádány, Róza; McKee, Martin; Szűcs, Sándor

2015-04-01

A large volume of alcoholic beverages containing aliphatic alcohols is consumed worldwide. Previous studies have confirmed the presence of ethanol-induced immunosuppression in heavy drinkers, thereby increasing susceptibility to infectious diseases. However, the aliphatic alcohols contained in alcoholic beverages might also impair immune cell function, thereby contributing to a further decrease in microbicidal activity. Previous research has shown that aliphatic alcohols inhibit phagocytosis by granulocytes but their effect on human monocytes has not been studied. This is important as they play a crucial role in engulfment and killing of pathogenic microorganisms and a decrease in their phagocytic activity could lead to impaired antimicrobial defence in heavy drinkers. The aim of this study was to measure monocyte phagocytosis following their treatment with those aliphatic alcohols detected in alcoholic beverages. Monocytes were separated from human peripheral blood and phagocytosis of opsonized zymosan particles by monocytes treated with ethanol and aliphatic alcohols individually and in combination was determined. It was shown that these alcohols could suppress the phagocytic activity of monocytes in a concentration-dependent manner and when combined with ethanol, they caused a further decrease in phagocytosis. Due to their additive effects, it is possible that they may inhibit phagocytosis in a clinically meaningful way in alcoholics and episodic heavy drinkers thereby contribute to their increased susceptibility to infectious diseases. However, further research is needed to address this question.

Chemistry of aliphatic sulfurpentafluoride derivatives

International Nuclear Information System (INIS)

Bissell, E.R.

1975-01-01

This report summarizes the literature through 1974 on aliphatic sulfurpentafluoride compounds. Methods of preparation and methods of transforming one pentafluorothio compound into another are briefly discussed. The physical properties of all known derivatives are tabulated

Degradation of biogenetic amines by gamma radiation process and identification by GC/MS

Energy Technology Data Exchange (ETDEWEB)

Cardozo, Monique; Souza, Stefania P. de; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME, Instituto Militar de Engenharia, RJ (Brazil)

2011-07-01

Biogenic amines are low molecular weight organic bases with aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structures that can be found in several foods, in which they are mainly produced by microbial decarboxylation of amino acids. The reasons to control amines in food are their potential toxicity and their use like food quality markers. The consumption of food containing large amounts of biogenic amines can result in allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Biogenic amines are also known as possible precursors of carcinogens, such as N-nitrosamines. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth. However, control measures to reduce their levels once formed need to be also considered. The biogenic amines are frequently found in high concentrations and not reduced by high-temperature treatment, which makes difficult to use conventional methods of food preservation for this purpose. Food irradiation has been used in many countries for inhibition of sprouting, destruction of food borne insects, extension of shelf life or improvement of the technological of food. Irradiation is also known as a good method for inactivating pathogens and reducing microorganisms in food materials. Furthermore, besides the sanitary purpose, irradiation technology in new trials can be applied to induce radiolysis of toxic contaminants in food products reducing their content. This study has the objective to evaluate the effect of different gamma irradiation doses (1, 3 and 5kGy) in methanol solutions of three different biogenic amines: tryptamine, tyramine and b-phenylethylamine. The solutions were prepared using standard biogenic amines purchased from Sigma-Aldrich Brazil and methanol HPLC grade with a concentration of 100 {mu}g/mL. They were irradiated in Centro Tecnologico do Exercito

Degradation of biogenetic amines by gamma radiation process and identification by GC/MS

International Nuclear Information System (INIS)

Cardozo, Monique; Souza, Stefania P. de; Lima, Keila dos S.C.; Lima, Antonio L. dos S.

2011-01-01

Biogenic amines are low molecular weight organic bases with aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethylamine) or heterocyclic (histamine, tryptamine) structures that can be found in several foods, in which they are mainly produced by microbial decarboxylation of amino acids. The reasons to control amines in food are their potential toxicity and their use like food quality markers. The consumption of food containing large amounts of biogenic amines can result in allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Biogenic amines are also known as possible precursors of carcinogens, such as N-nitrosamines. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth. However, control measures to reduce their levels once formed need to be also considered. The biogenic amines are frequently found in high concentrations and not reduced by high-temperature treatment, which makes difficult to use conventional methods of food preservation for this purpose. Food irradiation has been used in many countries for inhibition of sprouting, destruction of food borne insects, extension of shelf life or improvement of the technological of food. Irradiation is also known as a good method for inactivating pathogens and reducing microorganisms in food materials. Furthermore, besides the sanitary purpose, irradiation technology in new trials can be applied to induce radiolysis of toxic contaminants in food products reducing their content. This study has the objective to evaluate the effect of different gamma irradiation doses (1, 3 and 5kGy) in methanol solutions of three different biogenic amines: tryptamine, tyramine and b-phenylethylamine. The solutions were prepared using standard biogenic amines purchased from Sigma-Aldrich Brazil and methanol HPLC grade with a concentration of 100 μg/mL. They were irradiated in Centro Tecnologico do Exercito

Novel bioreducible poly(amido amine)s for highly efficient gene delivery

NARCIS (Netherlands)

Lin, C.; Zhong, Zhiyuan; Lok, Martin C.; Jiang, Xulin; Hennink, Wim E.; Feijen, Jan; Engbersen, Johannes F.J.

2007-01-01

A series of novel bioreducible poly(amido amine)s containing multiple disulfide linkages (SS-PAAs) were synthesized and evaluated as nonviral gene vectors. These linear SS-PAAs could be easily obtained by Michael-type polyaddition of various primary amines to the disulfide-containing cystamine

Amine-catalyzed direct aldol reactions of hydroxy- and dihydroxyacetone: biomimetic synthesis of carbohydrates.

Science.gov (United States)

Popik, Oskar; Pasternak-Suder, Monika; Leśniak, Katarzyna; Jawiczuk, Magdalena; Górecki, Marcin; Frelek, Jadwiga; Mlynarski, Jacek

2014-06-20

This article presents comprehensive studies on the application of primary, secondary, and tertiary amines as efficient organocatalysts for the de novo synthesis of ketoses and deoxyketoses. Mimicking the actions of aldolase enzymes, the synthesis of selected carbohydrates was accomplished in aqueous media by using proline- and serine-based organocatalysts. The presented methodology also provides direct access to unnatural L-carbohydrates from the (S)-glyceraldehyde precursor. Determination of the absolute configuration of all obtained sugars was feasible using a methodology consisting of concerted ECD and VCD spectroscopy.

Aliphatic isocyanurates and polyisocyanurate networks

NARCIS (Netherlands)

Driest, Pieter Job; Lenzi, V.; Marques, L.S.A.; Ramos, M.M.D; Dijkstra, D.J.; Richter, F.U.; Stamatialis, Dimitrios; Grijpma, Dirk W.

2016-01-01

The production, processing, and application of aliphatic isocyanate (NCO)-based thermosets such as polyurethane coatings and adhesives are generally limited by the surprisingly high viscosity of tri-functionality and higher-functionality isocyanurates. These compounds are essential crosslinking

Aliphatic isocyanurates and polyisocyanurate networks

NARCIS (Netherlands)

Driest, P. J.; Lenzi, V.; Marques, L. S. A.; Ramos, M. M. D.; Dijkstra, D. J.; Richter, F. U.; Stamatialis, D.; Grijpma, D. W.

2017-01-01

The production, processing, and application of aliphatic isocyanate (NCO)-based thermosets such as polyurethane coatings and adhesives are generally limited by the surprisingly high viscosity of tri-functionality and higher-functionality isocyanurates. These compounds are essential crosslinking

Fate of aliphatic compounds in nitric acid processing solutions

International Nuclear Information System (INIS)

Clark, W.E.; Howerton, W.B.

1975-01-01

The reaction of hyperazeotropic iodic acid-saturated nitric acid with short chain aliphatic iodides, nitrates, and acids was studied in order to determine the conditions for complete removal of organic materials from nitric acid systems. The aliphatic iodides are converted to the nitrates and the nitrates in strong HNO 3 are extensively converted into CO 2 and acids. The aliphatic acids are rather stable; acetic acid was unattacked by boiling in 20M HNO 3 and n-butyric acid was 80 percent unattacked. The dibasic acids oxalic and malonic are extensively attacked, but succinic acid is relatively stable. A wet oxidation method is successful in destroying acetic acid in 5 to 8M HNO 3 . (U.S.)

Tsuji-Trost N-allylation with allylic acetates using cellulose-Pd catalyst

Science.gov (United States)

Allylic amines are synthesized using heterogeneous cellulose-Pd catalyst via N-allylation of amines; aliphatic and benzyl amines undergo facile reaction with substituted and unsubstituted allyl acetates in high yields.

Combinations of Aromatic and Aliphatic Radiolysis.

Science.gov (United States)

LaVerne, Jay A; Dowling-Medley, Jennifer

2015-10-08

The production of H(2) in the radiolysis of benzene, methylbenzene (toluene), ethylbenzene, butylbenzene, and hexylbenzene with γ-rays, 2-10 MeV protons, 5-20 MeV helium ions, and 10-30 MeV carbon ions is used as a probe of the overall radiation sensitivity and to determine the relative contributions of aromatic and aliphatic entities in mixed hydrocarbons. The addition of an aliphatic side chain with progressively from one to six carbon lengths to benzene increases the H(2) yield with γ-rays, but the yield seems to reach a plateau far below that found from a simple aliphatic such as cyclohexane. There is a large increase in H(2) with LET (linear energy transfer) for all of the substituted benzenes, which indicates that the main process for H(2) formation is a second-order process and dominated by the aromatic entity. The addition of a small amount of benzene to cyclohexane can lower the H(2) yield from the value expected from a simple mixture law. A 50:50% volume mixture of benzene-cyclohexane has essentially the same H(2) yield as cyclohexylbenzene at a wide variation in LET, suggesting that intermolecular energy transfer is as efficient as intramolecular energy transfer.

Aliphatic alkenes and alkynes

International Nuclear Information System (INIS)

Serep, D.

1985-01-01

Papers on radiolysis of aliphatic alkenes and alkynes published after 1968 are analytically reviewed. Kinetics and mechanisms of radiolytic processes, dependences of yields of intermediate and final products on conditions of their procedure and molecular structure of compounds are considered. Certain attention is paid to problems of dimerization and oligomerization at radiolysis of the considered compounds

Nickel-catalysed retro-hydroamidocarbonylation of aliphatic amides to olefins

Science.gov (United States)

Hu, Jiefeng; Wang, Minyan; Pu, Xinghui; Shi, Zhuangzhi

2017-05-01

Amide and olefins are important synthetic intermediates with complementary reactivity which play a key role in the construction of natural products, pharmaceuticals and manmade materials. Converting the normally highly stable aliphatic amides into olefins directly is a challenging task. Here we show that a Ni/NHC-catalytic system has been established for decarbonylative elimination of aliphatic amides to generate various olefins via C-N and C-C bond cleavage. This study not only overcomes the acyl C-N bond activation in aliphatic amides, but also encompasses distinct chemical advances on a new type of elimination reaction called retro-hydroamidocarbonylation. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for late-stage olefination of amide groups in complex compounds.

Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil

International Nuclear Information System (INIS)

Serrano, Antonio; Gallego, Mercedes; Gonzalez, Jose Luis; Tejada, Manuel

2008-01-01

A diesel fuel spill at a concentration of 1 L m -2 soil was simulated on a 12 m 2 plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. - The effect of aliphatic hydrocarbons contamination on soil quality was monitored over a period of 400 days after a Diesel fuel spill

Aliphatic amine oxides as ligands

International Nuclear Information System (INIS)

Garla, L.C.; Betarello, V.H.; Chiericato Junior, G.; De Giovani, W.F.

1984-01-01

The reaction between some hydrated lanthanide perchlorates with trimethylamine oxide (TMAO) was studied. Compounds of general formula Ln(Cl 4 ) 3 : . 5,5 TMAO (Ln = La, Pr, Er and Y) were isolated. (Author) [pt

ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions

Institute of Scientific and Technical Information of China (English)

Saeed Farhadi; Kosar Jahanara

2014-01-01

A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhy-dride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with sub-strates having other functional groups and it is suitable for practical organic synthesis.

Cell Wall Amine Oxidases: New Players in Root Xylem Differentiation under Stress Conditions

Directory of Open Access Journals (Sweden)

Sandip A. Ghuge

2015-07-01

Full Text Available Polyamines (PAs are aliphatic polycations present in all living organisms. A growing body of evidence reveals their involvement as regulators in a variety of physiological and pathological events. They are oxidatively deaminated by amine oxidases (AOs, including copper amine oxidases (CuAOs and flavin adenine dinucleotide (FAD-dependent polyamine oxidases (PAOs. The biologically-active hydrogen peroxide (H2O2 is a shared compound in all of the AO-catalyzed reactions, and it has been reported to play important roles in PA-mediated developmental and stress-induced processes. In particular, the AO-driven H2O2 biosynthesis in the cell wall is well known to be involved in plant wound healing and pathogen attack responses by both triggering peroxidase-mediated wall-stiffening events and signaling modulation of defense gene expression. Extensive investigation by a variety of methodological approaches revealed high levels of expression of cell wall-localized AOs in root xylem tissues and vascular parenchyma of different plant species. Here, the recent progresses in understanding the role of cell wall-localized AOs as mediators of root xylem differentiation during development and/or under stress conditions are reviewed. A number of experimental pieces of evidence supports the involvement of apoplastic H2O2 derived from PA oxidation in xylem tissue maturation under stress-simulated conditions.

Preservation of peptide moieties in three Spanish sulfur-rich Tertiary kerogens

Energy Technology Data Exchange (ETDEWEB)

Rio, J.C. del [Consejo Superior de Investigaciones Cientificas, Seville (Spain). Inst. de Recursos Naturales y Agrobiologia; Olivella, M.A.; Heras, F.X.D. de las [Escola Universitaria Politecnica de Manresa, Catalonia (Spain); Knicker, H. [Technische Universitaet Muenchen (Germany). Lehrstuhl fuer Bodenkunde

2004-09-01

Thermochemolysis with tetramethylammonium hydroxide (TMAH) and solid-state {sup 15}N NMR were utilized for the characterization of refractory organic nitrogen in Tertiary Spanish kerogens. The samples included sulfur-rich oil shales from the Ribesalbes (Serravallian), Libros (Tortonian) and Cerdanya (Tortonian) basins. Analysis using solid state {sup 15}N NMR showed that part of the refractory nitrogen in the kerogens corresponds to amide groups. Moreover, the release of amino acid derivatives after pyrolysis in the presence of TMAH indicated that this amide-N arose from peptide moieties. The amino acids released from the kerogens were dominated by high amounts of glycine and alanine. Minor amounts of aspartic acid, serine, {alpha}-aminobutyric acid and other unidentified amino acids were also detected. Because proteinaceous structures, including small peptides, are generally considered as being highly sensitive to diagenetic degradation, encapsulation of labile peptide material into aliphatic structures in S-rich kerogens (probably via lipid sulfurization) has been proposed to explain the survival of these moieties. Substantial amounts of fatty acids (as methyl esters) were also released from all the kerogens after pyrolysis/TMAH, indicating their highly aliphatic character. The production of both fatty acids and amino acids from the kerogens supports the encapsulation process. (author)

Estimates of Gibbs free energies of formation of chlorinated aliphatic compounds

NARCIS (Netherlands)

Dolfing, Jan; Janssen, Dick B.

1994-01-01

The Gibbs free energy of formation of chlorinated aliphatic compounds was estimated with Mavrovouniotis' group contribution method. The group contribution of chlorine was estimated from the scarce data available on chlorinated aliphatics in the literature, and found to vary somewhat according to the

Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock

Energy Technology Data Exchange (ETDEWEB)

Akinlua, A., E-mail: geochemresearch@yahoo.com [Fossil Fuels and Environmental Geochemistry Group, Department of Chemistry, Obafemi Awolowo University, Ile-Ife (Nigeria); Jochmann, M.A.; Laaks, J.; Ewert, A.; Schmidt, T.C. [Instrumental Analytical Chemistry, University Duisburg-Essen, Universitaetsstr, 5, 45141 Essen (Germany)

2011-04-08

The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105 deg. C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock.

Microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock

International Nuclear Information System (INIS)

Akinlua, A.; Jochmann, M.A.; Laaks, J.; Ewert, A.; Schmidt, T.C.

2011-01-01

The extraction of aliphatic hydrocarbons from petroleum source rock using nonionic surfactants with the assistance of microwave was investigated and the conditions for maximum yield were determined. The results showed that the extraction temperatures and kinetic rates have significant effects on extraction yields of aliphatic hydrocarbons. The optimum temperature for microwave-assisted nonionic surfactant extraction of aliphatic hydrocarbons from petroleum source rock was 105 deg. C. The optimum extraction time for the aliphatic hydrocarbons was at 50 min. Concentration of the nonionic surfactant solution and irradiation power had significant effect on the yields of aliphatic hydrocarbons. The yields of the analytes were much higher using microwave assisted nonionic surfactant extraction than with Soxhlet extraction. The recoveries of the n-alkanes and acyclic isoprenoid hydrocarbons for GC-MS analysis from the extractant nonionic surfactant solution by in-tube extraction (ITEX 2) with a TENAX TA adsorbent were found to be efficient. The results show that microwave-assisted nonionic surfactant extraction (MANSE) is a good and efficient green analytical preparatory technique for geochemical evaluation of petroleum source rock.

A sensitive method using SPME pre-concentration for the quantification of aromatic amines in indoor air.

Science.gov (United States)

Lucaire, Vincent; Schwartz, Jean-Jacques; Delhomme, Olivier; Ocampo-Torres, Ruben; Millet, Maurice

2018-03-01

Monitoring the levels of aliphatic and aromatic amines (AA) in indoor air is important to protect human health because of exposure to these compounds through diet and inhalation. A sampling and analytical method using XAD-2 cartridges and gas chromatography coupled to mass spectrometry used for assessing 25 AA in different smoking and non-smoking indoor environment was developed. After sampling and delivering 1 m 3 of air (6-8 h sampling), an adsorbent was ultrasonically extracted with acetonitrile, concentrated to 1 mL and diluted in 25 mL of water (pH = 9; 5% NaCl), and then extracted for 40 min at 80 °C using a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and injected in a GC/MS system. With this method, 22 of the 25 AA can be analyzed with detection limits up to five times lower than that of classic liquid injection. Benzylamine, 3-aminophenol, and 4-aminophenol were not detected with the solid-phase micro-extraction (SPME) method. It can be assumed that aminophenols required a derivatization step for their analysis by GC as these molecules were not detected regardless of the injection mode used. Graphical abstract Analysis of aromatic amines in indoor air by SPME-GC/MS.

Bioreducible poly(amido amine)s for non-viral gene delivery

NARCIS (Netherlands)

Lin, C.

2008-01-01

This thesis describes the design and development of bioreducible poly(amido amine)s as non-viral vectors for gene delivery in vitro and in vivo. The structural influences of these polymers on their physico-chemical properties and gene delivery properties, transfection capability and cytotoxicity in

The influence of aliphatic side chain of anacardic acid on molecular ...

African Journals Online (AJOL)

Interestingly, the presence of the aliphatic side chain in AnMcr resulted in more uniform imprinted beads as compared to particle agglomerates obtained from SaMcr in the presence of propranolol template. Therefore, the aliphatic side chain of anacardic acid improves both molecular recognition of imprinted polymers as ...

A statistical approach to the interpretation of aliphatic hydrocarbon distributions in marine sediments

Science.gov (United States)

Rapp, J.B.

1991-01-01

Q-mode factor analysis was used to quantitate the distribution of the major aliphatic hydrocarbon (n-alkanes, pristane, phytane) systems in sediments from a variety of marine environments. The compositions of the pure end members of the systems were obtained from factor scores and the distribution of the systems within each sample was obtained from factor loadings. All the data, from the diverse environments sampled (estuarine (San Francisco Bay), fresh-water (San Francisco Peninsula), polar-marine (Antarctica) and geothermal-marine (Gorda Ridge) sediments), were reduced to three major systems: a terrestrial system (mostly high molecular weight aliphatics with odd-numbered-carbon predominance), a mature system (mostly low molecular weight aliphatics without predominance) and a system containing mostly high molecular weight aliphatics with even-numbered-carbon predominance. With this statistical approach, it is possible to assign the percentage contribution from various sources to the observed distribution of aliphatic hydrocarbons in each sediment sample. ?? 1991.

Substrate specific hydrolysis of aromatic and aromatic-aliphatic esters in orchid tissue cultures

Directory of Open Access Journals (Sweden)

Agnieszka Mironowicz

2014-01-01

Full Text Available We found that tissue cultures of higher plants were able, similarly as microorganisms, to transform low-molecular-weight chemical compounds. In tissue cultures of orchids (Cymbidium 'Saint Pierre' and Dendrobium phalaenopsis acetates of phenols and aromatic-aliphatic alcohols were hydrolyzed, whereas methyl esters of aromatic and aromatic-aliphatic acids did not undergo this reaction. Acetates of racemic aromatic-aliphatic alcohols were hydrolyzed with distinct enantiospecificity.

Oxidation of fluoroquinolone antibiotics and structurally related amines by chlorine dioxide: Reaction kinetics, product and pathway evaluation.

Science.gov (United States)

Wang, Pei; He, Yi-Liang; Huang, Ching-Hua

2010-12-01

Fluoroquinolones (FQs) are a group of widely prescribed antibiotics and have been frequently detected in the aquatic environment. The reaction kinetics and transformation of seven FQs (ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR), ofloxacin (OFL), lomefloxacin (LOM), pipemidic acid (PIP) and flumequine (FLU)) and three structurally related amines (1-phenylpiperazine (PP), N-phenylmorpholine (PM) and 4-phenylpiperidine (PD)) toward chlorine dioxide (ClO(2)) were investigated to elucidate the behavior of FQs during ClO(2) disinfection processes. The reaction kinetics are highly pH-dependent, can be well described by a second-order kinetic model incorporating speciation of FQs, and follow the trend of OFL > ENR > CIP ∼ NOR ∼ LOM > > PIP in reactivity. Comparison among FQs and related amines and product characterization indicate that FQs' piperazine ring is the primary reactive center toward ClO(2). ClO(2) likely attacks FQ's piperazinyl N4 atom followed by concerted fragmentation involving piperazinyl N1 atom, leading to dealkylation, hydroxylation and intramolecular ring closure at the piperazine moiety. While FQs with tertiary N4 react faster with ClO(2) than FQs with secondary N4, the overall reactivity of the piperazine moiety also depends strongly on the quinolone ring through electronic effects. The reaction rate constants obtained in clean water matrix can be used to model the decay of CIP by ClO(2) in surface water samples, but overestimate the decay in wastewater samples. Overall, transformation of FQs, particularly for those with tertiary N4 amines, could be expected under typical ClO(2) disinfection conditions. However, the transformation may not eliminate antibacterial activity because of little destruction at the quinolone ring. Copyright © 2010 Elsevier Ltd. All rights reserved.

Synthesis of vinyl phosphites

International Nuclear Information System (INIS)

Kabachnik, M.M.; Novikova, Z.S.; Neganova, E.G.; Lutsenko, I.F.

1986-01-01

The authors investigated the reactions of phosphoriodidites and phosphinous iodides with a number of aldehydes and ketones in presence of tertiary amines (triethylamine, pyridine, N,N-diethylaniline), and they have shown that as a result of the reactions the corresponding vinyl esters of phosphorus acids are formed. The reactions of phosphoriodidites (and phosphorodiamidous iodides) with aliphatic aldehydes (acetaldehyde, propionaldehyde, butyraldehyde, and isobutyraldehyde) go at a molar reactant ratio of 1:1 in either at room temperature and are practically complete in 5-6 h. The yields of the alkenyl phosphites (phosphorodiamidites) were 45-70%. The compositions and structures of the compounds obtained were confirmed by elemental analysis and the IR and 1 H and 31 P NMR spectra

Electrogenerated chemiluminescence of tris(2,2' bipyridine)ruthenium(II) using common biological buffers as co-reactant, pH buffer and supporting electrolyte.

Science.gov (United States)

Kebede, Noah; Francis, Paul S; Barbante, Gregory J; Hogan, Conor F

2015-11-07

A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.

Determination of airborne, volatile amines from polyurethane foams by sorption onto a high-capacity cation-exchange resin based on poly(succinic acid).

Science.gov (United States)

Seeber, G; Buchmeiser, M R; Bonn, G K; Bertsch, T

1998-06-05

A high-capacity carboxylic acid-functionalized resin prepared by ring-opening metathesis polymerization based on cross-linked endo,endo-poly(norborn-2-ene-5,6-dicarboxylic acid) was used for the sampling of volatile, airborne amines from polyurethane (PU) foams. Six tertiary amines which represent commonly used promotors for the formation of PUs from diisocyanates and polyols, namely pentamethyldiethylenetriamine, diazabicyclooctane, N-methylmorpholine, N-ethylmorphine, 1,4-dimethylpiperazine and N,N-dimethylethanolamine, were sorbed onto the new resin. The sorption behavior of the new material was investigated in terms of loading capacities, the influence of concentration, flow-rate as well as of the amount of resin. Breakthrough curves were recorded from each single component as well as of mixtures thereof. Finally, the resin was used for the sampling of amines evaporating from PU foams applied in buildings. Further information about time dependent concentration profiles were obtained using a combination of GC-MS and Fourier transform IR spectroscopy.

Trace amine-associated receptor 1-Family archetype or iconoclast?

Science.gov (United States)

Grandy, David K

2007-12-01

Interest has recently been rekindled in receptors that are activated by low molecular weight, noncatecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the "trace amines" (TA) beta-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of 2 publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers Borowsky et al. as TA1 and Bunzow et al. as TA receptor 1 (TAR1). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines, recombinant rodent and human TAR dose-dependently couple to the stimulation of adenosine 3',5'-monophosphate (cAMP) production. Structure-activity profiling based on this functional response has revealed that in addition to the TA, other biologically active compounds containing a 2-carbon aliphatic side chain linking an amino group to at least 1 benzene ring are potent and efficacious TA receptor agonists with amphetamine (AMPH), methamphetamine, 3-iodothyronamine, thyronamine, and dopamine (DA) among the most notable. Almost 100 years after the search for TAR began, numerous TA1/TAR1-related sequences, now called TA-associated receptors (TAAR), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TAR, a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCR. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast.

Elaboration of y-fanjasite catalysts containing radioactive elements such as uranyl ion in order to obtain aromatic solvents and heavy amines

International Nuclear Information System (INIS)

Nibou, D.

1990-06-01

The present work has shown the possibility of ammonia alkylation by n-octanol-l in gaseous phase, in presence of zeolitic catalysts. These catalysts are Y faujasitic types being used in waste water demineralization containing radioactive elements such as uranyl ion. This ion gives to the Y faujasite similar activity and selectivity as those of catalysts containing rare earths or transition metals. Toluene disproportionation has permitted to test beforehand catalysts destined to ammonia alkylation and to compare their mechanism. We have also proved the possibility to produce heavy amines such as tertiary amines which are used as uranium extractant agent. Some zeolites such as ZSM-5, beta, X, A, analcime, HS and Y faujasite type are prepared by hydrothermal synthesis method and characterized by some analysis techniques

The economics of amine usage

International Nuclear Information System (INIS)

Fountain, M.J.

1994-01-01

The EPRI computer programm, 'Aminemod', a PWR chemistry model, has been used to compare the technical advantages of the 'advanced' amines, ethanolamine, 1,2 diaminoethane and 5 aminopentanol over morpholine in generating an elevated pH in the moisture separator and the economics of using these amines has been assessed by using an MS Excel spreadsheet in conjunction with Aminemod. The advanced amines are capable of achieving 1 pH unit above neutrality, the EPRI target for prevention of erosion-corrison, at acceptable cost and, compared with 'conventional' amines, at considerably reduced ionic load on the condensate polisher. The exercise demonstrates that it is essential to evaluate the effect of an amine dosing regime on the total operating cost and that it is not possible to prejudge the economic outcome on the basis of an amine's purchase price. (orig.)

Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

International Nuclear Information System (INIS)

Hafidz Yusoff; Zaini Assim; Samsur Mohamad

2012-01-01

Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C 31 / C 19 and C 29 / C 31 indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

Process for removing halogenated aliphatic and aromatic compounds from petroleum products

Science.gov (United States)

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1983-09-20

A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

Bacterial degradation of monocyclic aromatic amines

Directory of Open Access Journals (Sweden)

Pankaj Kumar Arora

2015-08-01

Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

Amine Measurements in Boreal Forest Air

Science.gov (United States)

Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

2015-04-01

Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

Iodine - catalyzed prins cyclization of aliphatic and aromatic ketones

International Nuclear Information System (INIS)

Kishore, K.R.; Reddy, K.; Silva Junior, Luiz F.

2013-01-01

Iodine-catalyzed Prins cyclization of homoallylic alcohols and ketones was investigated. Anhydrous conditions and inert atmosphere are not required in this metal-free protocol. The reaction of 2-(3,4-dihydronaphthalene-1-yl)propan-1-ol with six aliphatic symmetric ketones gave the desired products in 67-77% yield. Cyclization was performed with four aliphatic unsymmetric ketones, leading to corresponding pyrans in 66-76% yield. Prins cyclization was also accomplished with four aromatic ketones in 37-66% yield. Finally, Prins cyclization of the monoterpene isopulegol and acetone was successfully achieved. (author)

Iodine - catalyzed prins cyclization of aliphatic and aromatic ketones

Energy Technology Data Exchange (ETDEWEB)

Kishore, K.R.; Reddy, K.; Silva Junior, Luiz F., E-mail: luizfsjr@iq.usp.br [Universidade de Sao Paulo (IQ/USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

2013-09-15

Iodine-catalyzed Prins cyclization of homoallylic alcohols and ketones was investigated. Anhydrous conditions and inert atmosphere are not required in this metal-free protocol. The reaction of 2-(3,4-dihydronaphthalene-1-yl)propan-1-ol with six aliphatic symmetric ketones gave the desired products in 67-77% yield. Cyclization was performed with four aliphatic unsymmetric ketones, leading to corresponding pyrans in 66-76% yield. Prins cyclization was also accomplished with four aromatic ketones in 37-66% yield. Finally, Prins cyclization of the monoterpene isopulegol and acetone was successfully achieved. (author)

Marine ecotoxicity of nitramines, transformation products of amine-based carbon capture technology.

Science.gov (United States)

Coutris, Claire; Macken, Ailbhe L; Collins, Andrew R; El Yamani, Naouale; Brooks, Steven J

2015-09-15

In the context of reducing CO2 emissions to the atmosphere, chemical absorption with amines is emerging as the most advanced technology for post-combustion CO2 capture from exhaust gases of fossil fuel power plants. Despite amine solvent recycling during the capture process, degradation products are formed and released into the environment, among them aliphatic nitramines, for which the environmental impact is unknown. In this study, we determined the acute and chronic toxicity of two nitramines identified as important transformation products of amine-based carbon capture, dimethylnitramine and ethanolnitramine, using a multi-trophic suite of bioassays. The results were then used to produce the first environmental risk assessment for the marine ecosystem. In addition, the in vivo genotoxicity of nitramines was studied by adapting the comet assay to cells from experimentally exposed fish. Overall, based on the whole organism bioassays, the toxicity of both nitramines was considered to be low. The most sensitive response to both compounds was found in oysters, and dimethylnitramine was consistently more toxic than ethanolnitramine in all bioassays. The Predicted No Effect Concentrations for dimethylnitramine and ethanolnitramine were 0.08 and 0.18 mg/L, respectively. The genotoxicity assessment revealed contrasting results to the whole organism bioassays, with ethanolnitramine found to be more genotoxic than dimethylnitramine by three orders of magnitude. At the lowest ethanolnitramine concentration (1mg/L), 84% DNA damage was observed, whereas 100mg/L dimethylnitramine was required to cause 37% DNA damage. The mechanisms of genotoxicity were also shown to differ between the two compounds, with oxidation of the DNA bases responsible for over 90% of the genotoxicity of dimethylnitramine, whereas DNA strand breaks and alkali-labile sites were responsible for over 90% of the genotoxicity of ethanolnitramine. Fish exposed to >3mg/L ethanolnitramine had virtually no DNA

Contribution to the study of the mechanism of extraction of uranyl chloride by long chain aliphatic amines

International Nuclear Information System (INIS)

Rubinstein, G.R.

1965-06-01

After having studied and developed the mechanisms which may 'a priori' explain the extraction process (co-ordination, ion association or intermediate mechanism), experience shows that ion association only should be taken into consideration. The structure of the organic complex of uranyl chloride has been defined on the basis of the study of the variation of the distribution coefficient of uranium between the two phases at the equilibrium as a function of successively the activity of Cl - ions in the aqueous phase, the concentration of amine salt in the organic phase and finally of the concentration of uranium in the aqueous phase. The plotting of the results in bi-logarithmic co-ordinates enables us to propose the following formula for the extracted compound: UO 2 Cl 4 -- (NR 3 H + ) 2 . The calculation of the equilibrium constant of formation of the organic compound of uranyl chloride has been possible in the case of diluted solutions of uranium only. (author) [fr

Study of the degradation mechanisms of amines used for the capture of CO{sub 2} in industrial fumes; Etude des mecanismes de degradation des amines utilisees pour le captage du CO{sub 2} dans les fumees

Energy Technology Data Exchange (ETDEWEB)

Lepaumier, H

2008-10-15

Global warming leads to reduce greenhouse gas emissions. Post combustion CO{sub 2} capture with solvent is the most advanced technology to reduce CO{sub 2} emissions in industrial fumes. A major problem associated with chemical absorption of CO{sub 2} using the benchmark ethanolamine (MEA) is solvent degradation through irreversible side reactions with CO{sub 2} and O{sub 2} which leads to numerous harmful impacts to the process: corrosion, solvent loss, foaming, fouling, and viscosity increase. So, developing new amines with higher chemical stability is essential. This work is based on the chemical stability study of 17 different molecules. Their structures have been chosen in order to establish structure-property relationships: alkanolamines, known for gas treatment application (MEA, DEA, MDEA, AMP...), di-amines, and tri-amines without alcohol function. Impact of temperature, CO{sub 2}, and O{sub 2} on degradation has been studied. Strong experimental conditions have been used to observe significant degradation after a 15 days experiment. Separation, identification and quantification of degradation products have been performed by using different testing instructions such as gas chromatography, mass spectrometry, ionic chromatography and NMR. Different mechanisms are proposed to explain most of degradation compounds. Radical reactions (dealkylation, alkylation, ring-closure reactions and piperazinones formation) are involved under O{sub 2} pressure whereas CO{sub 2} induces ionic reactions (dealkylation, alkylation, addition, ring-closure reactions and oxazolidinones or imidazolidinones formation). Large discrepancies of stability are noticed among the different amines. Knowledge of degradation products and reaction mechanisms has thus permitted to establish some relationships between structure and chemical stability: for example, role of the amine function (primary, secondary, tertiary), impact of alkyl chain length between the two amino groups and steric

Study of the degradation mechanisms of amines used for the capture of CO2 in industrial fumes

International Nuclear Information System (INIS)

Lepaumier, H.

2008-10-01

Global warming leads to reduce greenhouse gas emissions. Post combustion CO 2 capture with solvent is the most advanced technology to reduce CO 2 emissions in industrial fumes. A major problem associated with chemical absorption of CO 2 using the benchmark ethanolamine (MEA) is solvent degradation through irreversible side reactions with CO 2 and O 2 which leads to numerous harmful impacts to the process: corrosion, solvent loss, foaming, fouling, and viscosity increase. So, developing new amines with higher chemical stability is essential. This work is based on the chemical stability study of 17 different molecules. Their structures have been chosen in order to establish structure-property relationships: alkanolamines, known for gas treatment application (MEA, DEA, MDEA, AMP...), di-amines, and tri-amines without alcohol function. Impact of temperature, CO 2 , and O 2 on degradation has been studied. Strong experimental conditions have been used to observe significant degradation after a 15 days experiment. Separation, identification and quantification of degradation products have been performed by using different testing instructions such as gas chromatography, mass spectrometry, ionic chromatography and NMR. Different mechanisms are proposed to explain most of degradation compounds. Radical reactions (dealkylation, alkylation, ring-closure reactions and piperazinones formation) are involved under O 2 pressure whereas CO 2 induces ionic reactions (dealkylation, alkylation, addition, ring-closure reactions and oxazolidinones or imidazolidinones formation). Large discrepancies of stability are noticed among the different amines. Knowledge of degradation products and reaction mechanisms has thus permitted to establish some relationships between structure and chemical stability: for example, role of the amine function (primary, secondary, tertiary), impact of alkyl chain length between the two amino groups and steric hindrance. (author)

Reactivity of group IV (100) semiconductor surfaces towards organic compounds

Science.gov (United States)

Wang, George T.

The reactions of simple and multifunctional organic compounds with the clean silicon, germanium, and diamond (100)-2 x 1 semiconductor surfaces have been investigated using a combination of multiple internal reflection infrared spectroscopy and quantum chemistry density functional theory calculations. From these studies, an improved understanding of the atomic level reactivity of these semiconductor surfaces has been obtained, along with insights into how to achieve their selective coupling with organics of desired and varied functionality. In addition to the Si(100) and Ge(100) surfaces, our results show that cycloaddition chemistry can also be extended to the diamond (100) surface. At room temperature, 1,3-butadiene was found to form a Diels-Alder product with the diamond (100) surface, as evidenced by isotopic substitution experiments and comparison of the surface adduct with its direct molecular analogue, cyclohexene. The reactions of other classes of molecules in addition to alkenes on the Si(100) and Ge(100) surfaces, including a series of five-membered cyclic amines, were also examined. For tertiary aliphatic amines on Si(100) and both secondary and tertiary aliphatic amines on Ge(100), a majority of the molecules were observed to become stably trapped in dative-bonded precursor states rather than form energetically favorable dissociation products. For pyrrole, aromaticity was found to play a defining role in its reactivity, and a comparison of its molecular and surface reactivity reveals interesting similarities. To probe the factors controlling the selectivity of organic reactions on clean semiconductor surfaces, the adsorption of acetone and a series of unsaturated ketones was also investigated. The reaction of acetone on Ge(100) was found to be under thermodynamic control at room temperature, resulting in the formation of an "ene" product rather than the kinetically favored [2+2] C=O cycloaddition product previously observed on the Si(100) surface. In

Rigid particle toughening of aliphatic polyketone

NARCIS (Netherlands)

Zuiderduin, W.C.J.; Huetink, Han; Gaymans, R.J.

2006-01-01

The influence of precipitated calcium carbonate particles on the toughening behaviour of aliphatic polyketone has been studied. The calcium carbonate particles had a particle size of 0.7 mm and a stearic acid coating (1%). Composites of 0e31.5 vol% CaCO3 content have been compounded and injection

The Azomethine Ylide Route to Amine C–H Functionalization: Redox-Versions of Classic Reactions and a Pathway to New Transformations

Science.gov (United States)

2016-01-01

Conspectus Redox-neutral methods for the functionalization of amine α-C–H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C–H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet–Spengler, and Kabachnik–Fields reactions, Friedel–Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C–H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic

The azomethine ylide route to amine C-H functionalization: redox-versions of classic reactions and a pathway to new transformations.

Science.gov (United States)

Seidel, Daniel

2015-02-17

Conspectus Redox-neutral methods for the functionalization of amine α-C-H bonds are inherently efficient because they avoid external oxidants and reductants and often do not generate unwanted byproducts. However, most of the current methods for amine α-C-H bond functionalization are oxidative in nature. While the most efficient variants utilize atmospheric oxygen as the terminal oxidant, many such transformations require the use of expensive or toxic oxidants, often coupled with the need for transition metal catalysts. Redox-neutral amine α-functionalizations that involve intramolecular hydride transfer steps provide viable alternatives to certain oxidative reactions. These processes have been known for some time and are particularly well suited for tertiary amine substrates. A mechanistically distinct strategy for secondary amines has emerged only recently, despite sharing common features with a range of classic organic transformations. Among those are such widely used reactions as the Strecker, Mannich, Pictet-Spengler, and Kabachnik-Fields reactions, Friedel-Crafts alkylations, and iminium alkynylations. In these classic processes, condensation of a secondary amine with an aldehyde (or a ketone) typically leads to the formation of an intermediate iminium ion, which is subsequently attacked by a nucleophile. The corresponding redox-versions of these transformations utilize identical starting materials but incorporate an isomerization step that enables α-C-H bond functionalization. Intramolecular versions of these reactions include redox-neutral amine α-amination, α-oxygenation, and α-sulfenylation. In all cases, a reductive N-alkylation is effectively combined with an oxidative α-functionalization, generating water as the only byproduct. Reactions are promoted by simple carboxylic acids and in some cases require no additives. Azomethine ylides, dipolar species whose usage is predominantly in [3 + 2] cycloadditions and other pericyclic processes, have been

Trace Amine-Associated Receptor 1 – Family Archetype or Iconoclast?

Science.gov (United States)

Grandy, David K.

2009-01-01

Interest has recently been rekindled in receptors that are activated by low molecular weight, non-catecholic, biogenic amines that are typically found as trace constituents of various vertebrate and invertebrate tissues and fluids. The timing of this resurgent focus on receptors activated by the ‘trace amines’ (TAs) β-phenylethylamine (PEA), tyramine (TYR), octopamine (OCT), synephrine (SYN), and tryptamine (TRYP) is the direct result of two publications that appeared in 2001 describing the cloning of a novel G protein-coupled receptor (GPCR) referred to by their discoverers as TA1 (Borowsky et al., 2001) and TAR1 (Bunzow et al., 2001). When heterologously expressed in Xenopus laevis oocytes and various eukaryotic cell lines recombinant rodent and human TA receptors dose-dependently couple to the stimulation of cAMP production. Structure-activity profiling based on this functional response has revealed that in addition to the TAs, other biologically active compounds containing a 2 carbon aliphatic side chain linking an amino group to at least one benzene ring are potent and efficacious TA receptor agonists with amphetamine, methamphetamine, 3-iodothyronamine, thyronamine, and dopamine among the most notable. Almost 100 years after the search for TA receptors began numerous TA1/TAR1-related sequences, now called Trace Amine-Associated Receptors (TAARs), have been identified in the genome of every species of vertebrate examined to date. Consequently, even though heterologously expressed TAAR1 fits the pharmacological criteria established for a bona fide TA receptor a major challenge for those working in the field is to discern the in vivo pharmacology and physiology of each purported member of this extended family of GPCRs. Only then will it be possible to establish whether TAAR1 is the family archetype or an iconoclast. PMID:17888514

Notch sensitivity of aliphatic polyketone terpolymers

NARCIS (Netherlands)

Zuiderduin, W.C.J.; Huetink, Han; Gaymans, R.J.

2004-01-01

The notch sensitivity of aliphatic polyketone (PK) terpolymers was investigated in this article. The notch-tip radius was varied between the size of an actual propagating crack tip of 1-2 m and the largest notch tip of 1000 m radius. The larger notch-tip radii (1000-15 m) were milled into the

New insight on aliphatic linkages in the macromolecular organic fraction of Orgueil and Murchison meteorites through ruthenium tetroxide oxidation

Science.gov (United States)

Remusat, Laurent; Derenne, Sylvie; Robert, François

2005-09-01

Ruthenium tetroxide oxidation was used to examine the macromolecular insoluble organic matter (IOM) from the Orgueil and Murchison meteorites and especially to characterize the aliphatic linkages. Already applied to various terrestrial samples, ruthenium tetroxide is a selective oxidant which destroys aromatic units, converting them into CO 2, and yields aliphatic and aromatic acids. In our experiment on chondritic IOM, it produces mainly short aliphatic diacids and polycarboxylic aromatic acids. Some short hydroxyacids are also detected. Aliphatic diacids are interpreted as aliphatic bridges between aromatic units in the chemical structure, and polycarboxylic aromatic acids are the result of the fusion of polyaromatic units. The product distribution shows that aliphatic links are short with numerous substitutions. No indigenous monocarboxylic acid was detected, showing that free aliphatic chains must be very short (less than three carbon atoms). The hydroxyacids are related to the occurrence of ester and ether functional groups within the aliphatic bridges between the aromatic units. This technique thus allows us to characterize in detail the aliphatic linkages of the IOMs, and the derived conclusions are in agreement with spectroscopic, pyrolytic, and degradative results previously reported. Compared to terrestrial samples, the aliphatic part of chondritic IOM is shorter and highly substituted. Aromatic units are smaller and more cross-linked than in coals, as already proposed from NMR data. Orgueil and Murchison IOM exhibit some tiny differences, especially in the length of aliphatic chains.

Sillica Gel-Amine from Geothermal Sludge

Science.gov (United States)

Muljani, S.; Pujiastuti, C.; Wicaksono, P.; Lutfianingrum, R.

2018-01-01

Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

Aliphatic semisynthetic amino terminal variants of myoglobin: enrichment with carbon-13, determination and interpretation of terminal pK values and motions

International Nuclear Information System (INIS)

Busch, M.R.

1985-01-01

The synthesis of a series of myoglobins substituted in the amino terminal residue to provide variation in the aliphatic nature of the side chain and enrichment in 13 C was accomplished by semisynthetic methods. The replacements of valine, the native first residue, included 13 C enriched glycine, alanine, valine, leucine, and isoleucine. The products were extensively characterized and found to be virtually indistinguishable by most physical methods. 13 C NMR spectroscopy showed significant differences in the amino terminal pK value, ranging from 7.72 for myoglobin to 7.15 for myoglobin. Consideration of the electrostatic effects of the charge array indicated a balance of interactions at this site not significantly altered by variations in the side chain. By examination of the crystal structure, consideration of earlier work regarding the interactions of the side chain of Leu-2, and data regarding the motions of the terminal residue, it was concluded that the interaction of the side chain of the first residue with the hydrophobic cluster formed primarily by close contact of invariant residues Leu-2 and Leu-137 was the primary cause for the reduction in the terminal pK values seen for the larger aliphatics. By restricting the freedom of the residue, this interaction limits the available hydration volume, and consequently favors the unprotonated form of the amine. The concurrent observation of both functional elements in the series of α amino terminal residues brings out the interrelated consequences for the two categories of solvent interactions controlling structural and functional properties in a graded way

The economics of amine usage

International Nuclear Information System (INIS)

Fountain, M.J.

1994-01-01

Research carried out over the past decade in the USA (funded by EPRI) and by the CEGB/Nuclear Electric in the UK has identified several thermally stable, low-toxicity 'advanced' amines with good high-temperature basicity and low steam-water distribution ratio. As a direct result of this work several US PWR stations are now evaluating monoethanolamine (ETA) and Nuclear Electric's Wylfa Power Station (magnox) now doses 5 aminopentanol (5AP) instead of AMP, which had successfully combated erosion-corrosion for the past nine years. It has recently been stated that the use of 5AP ''...could save Nuclear Electric up to 1.5M pounds per year''. To provide US power station chemists with a tool for tailoring amine dosage to their own plant requirements EPRI has developed a computer model, Aminmod, which can, with user-defined circuit parameters and amine feed concentrations, calculate amine concentrations and pH(t) values at various points around the circuit. To complement this model a user-friendly spreadsheet program is being developed which will work in conjunction with Aminmod, via active links, to calculate the total operating cost associated with the selected amine dosing regime and compare alternative scenarios. This paper discusses the relationship between the technical and economic aspects of choosing an amine dosing regime and draws on combined Aminmod/spreadsheet results to illustrate how differences in amine properties can influence the optimum economic solution for a typical PWR. (author). 3 figs., 2 tabs., 5 refs

Amines, Astrocytes and Arousal

OpenAIRE

Bazargani, N.; Attwell, D.

2017-01-01

Amine neurotransmitters, such as noradrenaline, mediate arousal, attention, and reward in the CNS. New data suggest that, from flies to mammals, a major mechanism for amine transmitter action is to raise astrocyte [Ca2+]i and release gliotransmitters that modulate neuronal activity and behavior.

Extraction of sulphates by long chain amines; Extraction des sulfates par les amines a longues chaines

Energy Technology Data Exchange (ETDEWEB)

Boirie, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-05-15

The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [French] L'extraction de l'acide sulfurique par des amines a longues chaines en solution organique a ete etudiee en vue de la determination de la valeur des constantes de stabilite des sulfates et bisulfates d'amines formes. Parmi les sulfates, nous nous sommes particulierement interesses au sulfate d'uranium et au sulfate de thorium. Nous avons determine les formules des complexes extractibles avec les amines, ainsi que les constantes de dissociation correspondantes. Nous avons remarque que pour le sulfate d'uranium, la formule du complexe ne depend que de la nature de l'amine, alors que pour le thorium cette formule varie avec la structure de l'amine. Les formules determinees et la valeur des constantes calculees, nous ont permis de decrire les meilleures conditions d'extraction de l'uranium et du thorium ainsi que celles d'une separation de ces deux elements. Nous proposons enfin une application de cette etude au dosage de l'uranium dans les minerais, ou la separation de l'uranium par cette methode est

Biodegradation of aliphatic vs. aromatic hydrocarbons in fertilized arctic soils

Science.gov (United States)

Braddock, J.F.

1999-01-01

A study was carried out to test a simple bioremediation treatment strategy in the Arctic and analyze the influence of fertilization the degradation of aliphatic and aromatic hydrocarbons, e.g., pristine, n-tetradecane, n-pentadecane, 2-methylnaphthalene, naphthalene, and acenaphthalene. The site was a coarse sand pad that once supported fuel storage tanks. Diesel-range organics concentrations were 250-860 mg/kg soil at the beginning of the study. Replicate field plots treated with fertilizer yielded final concentrations of 0, 50, 100, or 200 mg N/kg soil. Soil pH and soil-water potentials decreased due to fertilizer application. The addition of fertilizer considerably increased soil respiration potentials, but not the populations of microorganisms measured. Fertilizer addition also led to ??? 50% loss of measured aliphatic and aromatic hydrocarbons in surface and subsurface soils. For fertilized plots, hydrocarbon loss was not associated with the quantity of fertilizer added. Losses of aliphatic hydrocarbons were ascribed to biotic processes, while losses of aromatic hydrocarbons were due to biotic and abiotic processes.

Diamination by n-coupling using a commercial laccase

CSIR Research Space (South Africa)

Wellington, Kevin W

2010-02-01

Full Text Available Nuclear diamination of p-hydrobenzoquinones with aromatic and aliphatic primary amines was catalyzed by a immobilised commercial laccase, Denilite II Base, from Novozymes. The amine and the p-hydrobenzoquinone was reacted under mild conditions (at...

Oxidation of amines by flavoproteins.

Science.gov (United States)

Fitzpatrick, Paul F

2010-01-01

Many flavoproteins catalyze the oxidation of primary and secondary amines, with the transfer of a hydride equivalent from a carbon-nitrogen bond to the flavin cofactor. Most of these amine oxidases can be classified into two structural families, the D-amino acid oxidase/sarcosine oxidase family and the monoamine oxidase family. This review discusses the present understanding of the mechanisms of amine and amino acid oxidation by flavoproteins, focusing on these two structural families. Copyright 2009 Elsevier Inc. All rights reserved.

Hydrogenation of unactivated enamines to tertiary amines: rhodium complexes of fluorinated phosphines give marked improvements in catalytic activity

Directory of Open Access Journals (Sweden)

Sergey Tin

2015-05-01

Full Text Available In the hydrogenation of sluggish unactivated enamine substrates, Rh complexes of electron-deficient phosphines are demonstrated to be far more reactive catalysts than those derived from triphenylphosphine. These operate at low catalyst loadings (down to 0.01 mol % and are able to reduce tetrasubstituted enamines. The use of the sustainable and environmentally benign solvent (R-limonene for the reaction is also reported with the amine isolated by acid extraction.

Controlling Nitrosamines, Nitramines, and Amines in Amine-Based CO₂ Capture Systems with Continuous Ultraviolet and Ozone Treatment of Washwater.

Science.gov (United States)

Dai, Ning; Mitch, William A

2015-07-21

Formation of nitrosamines and nitramines from reactions between flue gas NOx and the amines used in CO2 capture units has arisen as a significant concern. Washwater scrubbers can capture nitrosamines and nitramines. They can also capture amines, preventing formation of nitrosamines and nitramines downwind by amine reactions with ambient NOx. The continuous application of UV alone, or a combination of UV and ozone to the return line of a washwater treatment unit was evaluated to control the accumulation of nitrosamines, nitramines and amines in a laboratory-scale washwater unit. With model secondary amine solvents ranging from nonvolatile diethanolamine to volatile morpholine, application of 272-537 mJ/cm(2) UV incident fluence alone reduced the accumulation of nitrosamines and nitramines by approximately an order of magnitude. Modeling indicated that the gains achieved by UV treatment should increase over time, because UV treatment converts the time dependence of nitrosamine accumulation from a quadratic to a linear function. Ozone (21 mg/L) maintained low steady-state concentrations of amines in the washwater. While modeling indicated that more than 80% of nitrosamine accumulation in the washwater was associated with reaction of washwater amines with residual NOx, a reduction in nitrosamine accumulation rates due to ozone oxidation of amines was not fully realized because the ozonation products of amines reduced nitrosamine photolysis rates by competing for photons.

Chemical modifications and applications of alternating aliphatic polyketones

NARCIS (Netherlands)

Zhang, Youchun

2008-01-01

Alternating aliphatic polyketones, produced by co- and terpolymerization of carbon monoxide and olefins (mixtures of ethylene and propylene) using palladium-based homogeneous catalysis represent a very promising class of polymers for a wide range of applications. Besides many interesting chemical

Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA).

Science.gov (United States)

Chatterjee, Nachiketa; Goswami, Avijit

2015-08-07

A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.

Catalytic Enantioselective Addition of Organometallic Reagents to N-Formylimines Using Monodentate Phosphoramidite Ligands

NARCIS (Netherlands)

Pizzuti, Maria Gabriella; Minnaard, Adriaan J.; Feringa, Bernard

2008-01-01

The asymmetric synthesis of protected amines via the copper/phosphoramidite-catalyzed addition of organozinc and organoaluminum reagents to N-acylimines, generated in situ from aromatic and aliphatic α-amidosulfones, is reported. High yields of optically active N-formyl-protected amines and

Cyano-containing ionic liquids for the extraction of aromatic hydrocarbons from an aromatic/aliphatic mixture

NARCIS (Netherlands)

Meindersma, G.W.; Haan, de A.B.

2012-01-01

Ionic liquids can replace conventional solvents in aromatic/aliphatic extractions, if they have higher aromatic distribution coefficients and higher or similar aromatic/aliphatic selectivities. Also physical properties, such as density and viscosity, must be taken into account if a solvent is

shape selective synthesis of alkylamines over acid catalysts

NARCIS (Netherlands)

Veefkind, V.A.

1998-01-01

Aliphatic amines are amongst the most important chemical intermediates. The worldwide annual production of these amines is estimated to be several hundreds of thousands of tons. The most practiced production route is the reaction of ammonia with alcohols to produce alkylamines of different

Nano-biocomposites based on synthetic aliphatic polyesters and nanoclay

CSIR Research Space (South Africa)

Ojijo, Vincent O

2014-05-01

Full Text Available This article gives an overview of the recent developments in the preparation, characterisation, properties, crystallisation behaviour, and melt rheology of clay-containing composites of biodegradable synthetic aliphatic polyesters such as poly...

Enantioselective Direct α-Amination of Aldehydes via a Photoredox Mechanism: A Strategy for Asymmetric Amine Fragment Coupling

OpenAIRE

Cecere, Giuseppe; Koenig, Christian M.; Alleva, Jennifer L.; MacMillan, David W. C.

2013-01-01

The direct, asymmetric α-amination of aldehydes has been accomplished via a combination of photoredox and organocatalysis. Photon-generated, nitrogen-centered radicals undergo enantioselective α-addition to catalytically formed chiral enamines to directly produce stable α-amino aldehyde adducts bearing synthetically useful amine substitution patterns. Incorporation of a photolabile group on the amine precursor obviates the need to employ a photoredox catalyst in this transformation. Important...

Terpenoid composition and class of Tertiary resins from India

Energy Technology Data Exchange (ETDEWEB)

Dutta, Suryendu; Mallick, Monalisa; Mathews, Runcie Paul [Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India); Bertram, Norbert [LTA-Labor fuer Toxikologie und Analytik, Friedrichshoeher Str. 28, D-53639 Koenigswinter (Germany); Greenwood, Paul F. [John De Laeter Mass Spectrometry and WA Biogeochemitry Centres (M090), The University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009 (Australia); WA - Organic and Isotope Geochemistry Centre, Curtin University of Technology, Kent St., Bentley 6102 (Australia)

2009-10-01

The terpenoid composition and class of Tertiary resins preserved within lignites of Cambay, Kutch and Cauvery Basins of India have been characterized using Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS) and Fourier Transform Infrared (FTIR) Spectroscopy. Major pyrolysis products include cadalene-based C{sub 15}-bicyclic sesquiterpenoids with some C{sub 30} and C{sub 31} bicadinanes and bicadinenes typical of Class II or dammar resin. The occurrence of these terpenoids in Early Eocene sediments may extend the first appearance of Dipterocarpaceae angiosperms, the predominant source of this resin class, back to the Early Eocene epoch in India. The same terpenoid biomarkers have been detected in many SE Asian oils reflecting a close source relationship with these resins. Strong CH{sub 3} (1377 cm{sup -} {sup 1}) and other CH{sub x} (3000-2800 and 1460-1450 cm{sup -} {sup 1}) aliphatic absorptions of much larger intensity than the aromatic C = C (1560-1650 cm{sup -} {sup 1}) absorption were detected in the Indian resins by FTIR Spectroscopy, confirming the quantitative significance of the terpenoid pyrolysates. (author)

Towards understanding the role of amines in the SO2 hydration and the contribution of the hydrated product to new particle formation in the Earth's atmosphere.

Science.gov (United States)

Lv, Guochun; Nadykto, Alexey B; Sun, Xiaomin; Zhang, Chenxi; Xu, Yisheng

2018-08-01

By theoretical calculations, the gas-phase SO 2 hydration reaction assisted by methylamine (MA) and dimethylamine (DMA) was investigated, and the potential contribution of the hydrated product to new particle formation (NPF) also was evaluated. The results show that the energy barrier for aliphatic amines (MA and DMA) assisted SO 2 hydration reaction is lower than the corresponding that of water and ammonia assisted SO 2 hydration. In these hydration reactions, nearly barrierless reaction (only a barrier of 0.1 kcal mol -1 ) can be found in the case of SO 2  + 2H 2 O + DMA. These lead us to conclude that the SO 2 hydration reaction assisted by MA and DMA is energetically facile. The temporal evolution for hydrated products (CH 3 NH 3 + -HSO 3 - -H 2 O or (CH 3 ) 2 NH 2 + -HSO 3 - -H 2 O) in molecular dynamics simulations indicates that these complexes can self-aggregate into bigger clusters and can absorb water and amine molecules, which means that these hydrated products formed by the hydration reaction may serve as a condensation nucleus to initiate the NPF. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prediction of anticancer activity of aliphatic nitrosoureas using ...

African Journals Online (AJOL)

Design and development of new anticancer drugs with low toxicity is a very challenging task and computer aided methods are being increasingly used to solve this problem. In this study, we investigated the anticancer activity of aliphatic nitrosoureas using quantum chemical quantitative structure activity relation (QSAR) ...

Applicability of the theory of thermodynamic similarity to predict the enthalpies of vaporization of aliphatic aldehydes

Science.gov (United States)

Esina, Z. N.; Korchuganova, M. R.

2015-06-01

The theory of thermodynamic similarity is used to predict the enthalpies of vaporization of aliphatic aldehydes. The predicted data allow us to calculate the phase diagrams of liquid-vapor equilibrium in a binary water-aliphatic aldehyde system.

General Dialdehyde Click Chemistry for Amine Bioconjugation.

Science.gov (United States)

Elahipanah, Sina; O'Brien, Paul J; Rogozhnikov, Dmitry; Yousaf, Muhammad N

2017-05-17

The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research. In particular, primary amines are a ubiquitous functional group found in biological systems as free amino acids, as key side chain lysines in proteins, and in signaling molecules and metabolites and are also present in many natural product classes. Due to its abundance, the primary amine is the most convenient functional group handle in molecules for ligation to other molecules for a broad range of applications that impact all scientific fields. Because of the primary amine's central importance in synthetic chemistry, acid-base chemistry, redox chemistry, and biology, many methods have been developed to efficiently react with primary amines, including activated carboxylic acids, isothiocyanates, Michael addition type systems, and reaction with ketones or aldehydes followed by in situ reductive amination. Herein, we introduce a new traceless, high-yield, fast click-chemistry method based on the rapid and efficient trapping of amine groups via a functionalized dialdehyde group. The click reaction occurs in mild conditions in organic solvents or aqueous media and proceeds in high yield, and the starting dialdehyde reagent and resulting dialdehyde click conjugates are stable. Moreover, no catalyst or dialdehyde-activating group is required, and the only byproduct is water. The initial dialdehyde and the resulting conjugate are both straightforward to characterize, and the reaction proceeds with high atom economy. To demonstrate the broad scope of this new click

Biogenic amines degradation by microorganisms isolated from cheese

Directory of Open Access Journals (Sweden)

Irena Butor

2017-01-01

Full Text Available The aim of this study was the isolation and characterization of microorganisms able to degrade biogenic amines and their identification. Individual microorganisms were obtained by isolation from commercially available foodstuffs and food produced in the technological laboratories of Faculty of Technology, Tomas Bata University in Zlín and subsequently identified by MALDI-TOF MS. The results of MALDI-TOF MS identification were verified by 16S rRNA sequenation. In this work was studied the ability of 5 bacterial strains positive to biogenic amines degradation isolated from dairy products to decrease biogenic amines content in vitro and quantified reduction in the concentration of biogenic amines tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine and tyramine. The level of degradation (decrease of biogenic amines was determined on the base of the ability to grow in media with biogenic amines as the sole source carbon and nitrogen. The isolated strains with the ability of degradation of one or more biogenic amines were cultured in medium supplemented with relevant biogenic amines, the media derivatized with dansyl chloride and these amines separated by HPLC at a wavelength of 254 nm. From five tested strains identified as Bacillus subtilis, Bacillus pumilus, Enterobacter cloacae, Rhizobium radiobacter and Acinetobacter pitii, isolated from gouda type cheese, the greatest ability of degradation was observed in Bacillus subtilis, which was capable to degrade almost all amount of histamine, cadaverine and putrescine. Other four strains showed a lower rate of degradation than Bacillus subtilis, but the ability to degrade biogenic amines with these microorganisms was still significant.

Metabolism and Biomarkers of Heterocyclic Aromatic Amines in Molecular Epidemiology Studies: Lessons Learned from Aromatic Amines

Science.gov (United States)

2011-01-01

Aromatic amines and heterocyclic aromatic amines (HAAs) are structurally related classes of carcinogens that are formed during the combustion of tobacco or during the high-temperature cooking of meats. Both classes of procarcinogens undergo metabolic activation by N-hydroxylation of the exocyclic amine group, to produce a common proposed intermediate, the arylnitrenium ion, which is the critical metabolite implicated in toxicity and DNA damage. However, the biochemistry and chemical properties of these compounds are distinct and different biomarkers of aromatic amines and HAAs have been developed for human biomonitoring studies. Hemoglobin adducts have been extensively used as biomarkers to monitor occupational and environmental exposures to a number of aromatic amines; however, HAAs do not form hemoglobin adducts at appreciable levels and other biomarkers have been sought. A number of epidemiologic studies that have investigated dietary consumption of well-done meat in relation to various tumor sites reported a positive association between cancer risk and well-done meat consumption, although some studies have shown no associations between well-done meat and cancer risk. A major limiting factor in most epidemiological studies is the uncertainty in quantitative estimates of chronic exposure to HAAs and, thus, the association of HAAs formed in cooked meat and cancer risk has been difficult to establish. There is a critical need to establish long-term biomarkers of HAAs that can be implemented in molecular epidemioIogy studies. In this review article, we highlight and contrast the biochemistry of several prototypical carcinogenic aromatic amines and HAAs to which humans are chronically exposed. The biochemical properties and the impact of polymorphisms of the major xenobiotic-metabolizing enzymes on the biological effects of these chemicals are examined. Lastly, the analytical approaches that have been successfully employed to biomonitor aromatic amines and HAAs, and

Amidation of single-walled carbon nanotubes by a hydrothermal process for the electrooxidation of nitric oxide

International Nuclear Information System (INIS)

Kan Kan; Xia Tingliang; Li Li; Bi Hongmei; Fu Honggang; Shi Keying

2009-01-01

Single-walled carbon nanotubes (SWCNTs) have been amidated by hydrothermal treatment with different aliphatic amines. The amido groups modified on the surface of the SWCNTs were characterized by Fourier transform infrared spectroscopy. The electrooxidation of nitric oxide (NO) at the modified electrodes of amidated SWCNTs was investigated. The modified electrodes of amidated SWCNTs exhibited different electrocatalytic activity for NO when different aliphatic amines were being used. The electrode amidated by ammonia has the highest activity, which is 1.8 times value of the SWCNT modified electrode. The electrocatalytic activity of the amidated SWCNT modified electrodes depends on the length of the alkyl groups. The results demonstrate that hydrothermal treatment is an efficient way to modify SWCNTs with amines, and the reaction rate of NO electrooxidation can be changed by the amidation of SWCNTs.

Amine promoted, metal enhanced degradation of Mirex under high temperature conditions

Energy Technology Data Exchange (ETDEWEB)

Jallad, Karim N. [American University of Sharjah, Department of Chemistry, P.O. Box 26666, Sharjah (United Arab Emirates)]. E-mail: kjallad@runbox.com; Lynn, Bert C. [University of Kentucky, Department of Chemistry, Lexington, KY 40506-055 (United States); Alley, Earl G. [Mississippi State University, Department of Chemistry, MS State, MS 39762 (United States)

2006-07-31

In this study, zero-valent metal dehalogenation of mirex was conducted with amine solvents at high temperatures. Mirex was treated with excess amine in sealed glass tube reactors under nitrogen. The amines used were n-butyl amine (l), ethyl amine (l), dimethyl amine (g), diethyl amine (l), triethyl amine (l), trimethyl amine (g) and ammonia (g). The metals used were copper, zinc, magnesium, aluminum and calcium. The most suitable amine solvent and metal were selected by running a series of reactions with different amines and different zero-valent metals, in order to optimize the conditions under which complete degradation of mirex takes place. These dehalogenation reactions illustrated the role of zero-valent metals as reductants, whereas the amine solvents acted as proton donors. In this study, we report that mirex was completely degraded with diethyl amine (l) in the presence of copper at 100 deg. C and the hydrogenated products accounted for more than 94 of the degraded mirex.

omega-Amino acid:pyruvate transaminase from Alcaligenes denitrificans Y2k-2: a new catalyst for kinetic resolution of beta-amino acids and amines.

Science.gov (United States)

Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

2004-04-01

Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed omega-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic beta-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for L-beta-amino-n-butyric acid (L-beta-ABA). The enzyme converts various beta-amino acids and amines to the corresponding beta-keto acids and ketones by using pyruvate as an amine acceptor. The apparent K(m) and V(max) for L-beta-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM L-beta-ABA, the apparent K(m) and V(max) for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM D,L-beta-ABA, producing optically pure D-beta-ABA (99% enantiomeric excess) with 53% conversion.

ω-Amino Acid:Pyruvate Transaminase from Alcaligenes denitrificans Y2k-2: a New Catalyst for Kinetic Resolution of β-Amino Acids and Amines

Science.gov (United States)

Yun, Hyungdon; Lim, Seongyop; Cho, Byung-Kwan; Kim, Byung-Gee

2004-01-01

Alcaligenes denitrificans Y2k-2 was obtained by selective enrichment followed by screening from soil samples, which showed ω-amino acid:pyruvate transaminase activity, to kinetically resolve aliphatic β-amino acid, and the corresponding structural gene (aptA) was cloned. The gene was functionally expressed in Escherichia coli BL21 by using an isopropyl-β-d-thiogalactopyranoside (IPTG)-inducible pET expression system (9.6 U/mg), and the recombinant AptA was purified to show a specific activity of 77.2 U/mg for l-β-amino-n-butyric acid (l-β-ABA). The enzyme converts various β-amino acids and amines to the corresponding β-keto acids and ketones by using pyruvate as an amine acceptor. The apparent Km and Vmax for l-β-ABA were 56 mM and 500 U/mg, respectively, in the presence of 10 mM pyruvate. In the presence of 10 mM l-β-ABA, the apparent Km and Vmax for pyruvate were 11 mM and 370 U/mg, respectively. The enzyme exhibits high stereoselectivity (E > 80) in the kinetic resolution of 50 mM d,l-β-ABA, producing optically pure d-β-ABA (99% enantiomeric excess) with 53% conversion. PMID:15066855

Effects of a thirteen-week inhalation exposure to ethyl tertiary butyl ether on fischer-344 rats and CD-1 mice.

Science.gov (United States)

Medinsky, M A; Wolf, D C; Cattley, R C; Wong, B; Janszen, D B; Farris, G M; Wright, G A; Bond, J A

1999-09-01

The 1990 Clean Air Act Amendments require that oxygenates be added to automotive fuels to reduce emissions of carbon monoxide and hydrocarbons. One potential oxygenate is the aliphatic ether ethyl tertiary butyl ether (ETBE). Our objective was to provide data on the potential toxic effects of ETBE. Male and female Fisher 344 rats and CD-1 mice were exposed to 0 (control), 500, 1750, or 5000 ppm of ETBE for 6 h/day and 5 days/wk over a 13-week period. ETBE exposure had no effect on mortality and body weight with the exception of an increase in body weights of the female rats in the 5000-ppm group. No major changes in clinical pathology parameters were noted for either rats or mice exposed to ETBE for 6 (rats only) or 13 weeks. Liver weights increased with increasing ETBE-exposure concentration for both sexes of rats and mice. Increases in kidney, adrenal, and heart (females only) weights were noted in rats. Degenerative changes in testicular seminiferous tubules were observed in male rats exposed to 1750 and 5000 ppm but were not seen in mice. This testicular lesion has not been reported previously for aliphatic ethers. Increases in the incidence of regenerative foci, rates of renal cell proliferation, and alpha2u-globulin containing protein droplets were noted in the kidneys of all treated male rats. These lesions are associated with the male rat-specific syndrome of alpha2u-globulin nephropathy. Increases in the incidence of centrilobular hepatocyte hypertrophy and rates of hepatocyte cell proliferation were seen in the livers of male and female mice in the 5000-ppm group, consistent with a mitogenic response to ETBE. These two target organs for ETBE toxicity, mouse liver and male rat kidney, have also been reported for methyl tertiary butyl ether and unleaded gasoline.

Electrooxidation of aliphatic alcohols on palladium oxide catalyst prepared by pulsed electrodeposition technique

International Nuclear Information System (INIS)

Casella, Innocenzo G.

2009-01-01

Palladium film can be deposited on gold polycrystalline electrodes, from a deoxygenated alkaline solution containing 50 mM NaOH plus 0.5 mM K 2 Pd(CN) 4 . A multipulse sequence of potentials of equal amplitude and duration was used for the palladium deposition process. In particular, an optimized waveform of potentials of E 1 = 1.0 V vs. SCE and E 2 = -1.0 V vs. SCE for the relevant pulse duration of t 1 = 0.05 s and t 2 = 0.05 s, for 30 s, was used. Cyclic voltammetry and scanning electron microscopy (SEM) were employed to characterize the gold-palladium modified electrode (Au-Pd) towards the electrooxidation of aliphatic alcohols in alkaline solutions. The voltammetric study suggests that the kinetics involved in the alcohol electrooxidation at the Pd-Au electrode are sensibly higher than those observed on the bare Pd and Au electrodes. In addition, the most interesting aspect of the electrooxidation of aliphatic alcohols at the Au-Pd electrode was that as the number of methylene groups on the homologous series of aliphatic alcohols increased, the molar response also increased. Under pulsed chronoamerometric conditions (PCC), using an optimized triple pulse waveform of potentials the modified electrode exhibits interesting catalytic currents without any apparent poisoning effects during the oxidation of aliphatic alcohols.

Synthesis and bioelectrochemical behavior of aromatic amines.

Science.gov (United States)

Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Bolte, Michael; McKee, Vickie

2017-12-01

Four aromatic amines 1-amino-4-phenoxybenzene (A 1 ), 4-(4-aminophenyloxy) biphenyl (A 2 ), 1-(4-aminophenoxy) naphthalene (A 3 ) and 2-(4-aminophenoxy) naphthalene (A 4 ) were synthesized and characterized by elemental, spectroscopic (FTIR, NMR), mass spectrometric and single crystal X-ray diffraction methods. The compounds crystallized in monoclinic crystal system with space group P2 1 . Intermolecular hydrogen bonds were observed between the amine group and amine/ether acceptors of neighboring molecules. Electrochemical investigations were done using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). CV studies showed that oxidation of aromatic amines takes place at about 0.9 V (vs. Ag/AgCl) and the electron transfer (ET) process has irreversible nature. After first scan reactive intermediate were generated electrochemically and some other cathodic and anodic peaks also appeared in the succeeding scans. DPV study revealed that ET process is accompanied by one electron. DNA binding study of aromatic amines was performed by CV and UV-visible spectroscopy. These investigations revealed groove binding mode of interaction of aromatic amines with DNA. Copyright © 2017 Elsevier Inc. All rights reserved.

Aliphatic amine cured PDMS–epoxy interpenetrating network ...

Indian Academy of Sciences (India)

Unknown

Tg, heat-distortion temperature and reduced the percentage weight loss with ... The siliconized epoxy IPN, with better impact and thermal resistance, ... However, these materials also deteriorate ... the method of compounding remains the state of the art. ... geneity and to ascertain any chemical change during storage.

Structure and properties of porous films based on aliphatic copolyamide developed for cellular technologies

Czech Academy of Sciences Publication Activity Database

Dobrovol`skaya, I.P.; Popryadukhin, P.V.; Yudin, V. E.; Ivankova, E.M.; Elokhovskiy, V.Y.; Weishauptová, Zuzana; Balík, Karel

2015-01-01

Roč. 26, č. 1 (2015), article number 46 ISSN 0957-4530 Institutional support: RVO:67985891 Keywords : porous film * aliphatic copolyamide * structure * properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.272, year: 2015 http://www.stem-art.com/Library/Science/Structure%20and%20properties%20of%20porous%20films%20based%20on%20aliphatic%20copolyamide%20developed%20for%20cellular%20technologies.pdf

Amine Swingbed Payload Project Management

Science.gov (United States)

Walsch, Mary; Curley, Su

2013-01-01

The International Space Station (ISS) has been designed as a laboratory for demonstrating technologies in a microgravity environment, benefitting exploration programs by reducing the overall risk of implementing such technologies in new spacecraft. At the beginning of fiscal year 2010, the ISS program manager requested that the amine-based, pressure-swing carbon dioxide and humidity absorption technology (designed by Hamilton Sundstrand, baselined for the Orion Multi-Purpose Crew Vehicle, and tested at the Johnson Space Center in relevant environments, including with humans, since 2005) be developed into a payload for ISS Utilization. In addition to evaluating the amine technology in a flight environment before the first launch of the Orion vehicle, the ISS program wanted to determine the capability of the amine technology to remove carbon dioxide from the ISS cabin environment at the metabolic rate of the full 6 ]person crew. Because the amine technology vents the absorbed carbon dioxide and water vapor to space vacuum (open loop), additional hardware needed to be developed to minimize the amount of air and water resources lost overboard. Additionally, the payload system would be launched on two separate Space Shuttle flights, with the heart of the payload-the swingbed unit itself-launching a full year before the remainder of the payload. This paper discusses the project management and challenges of developing the amine swingbed payload in order to accomplish the technology objectives of both the open -loop Orion application as well as the closed-loop ISS application.

Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey

Directory of Open Access Journals (Sweden)

Ling Yin

2017-06-01

Full Text Available Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28, the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology (BoaMYB28 was identified in Chinese kale (Brassica oleracea var. alboglabra Bailey. Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate

Molecular Characterization of MYB28 Involved in Aliphatic Glucosinolate Biosynthesis in Chinese Kale (Brassica oleracea var. alboglabra Bailey).

Science.gov (United States)

Yin, Ling; Chen, Hancai; Cao, Bihao; Lei, Jianjun; Chen, Guoju

2017-01-01

Glucosinolates are Brassicaceae-specific secondary metabolites that act as crop protectants, flavor precursors, and cancer-prevention agents, which shows strong evidences of anticarcinogentic, antioxidant, and antimicrobial activities. MYB28 , the R2R3-MYB28 transcription factor, directly activates genes involved in aliphatic glucosinolate biosynthesis. In this study, the MYB28 homology ( BoaMYB28 ) was identified in Chinese kale ( Brassica oleracea var. alboglabra Bailey). Analysis of the nucleotide sequence indicated that the cDNA of BoaMYB28 was 1257 bp with an ORF of 1020 bp. The deduced BoaMYB28 protein was a polypeptide of 339 amino acid with a putative molecular mass of 38 kDa and a pI of 6.87. Sequence homology and phylogenetic analysis showed that BoaMYB28 was most closely related to MYB28 homologs from the Brassicaceae family. The expression levels of BoaMYB28 varies across the tissues and developmental stages. BoaMYB28 transcript levels were higher in leaves and stems compared with those in cotyledons, flowers, and siliques. BoaMYB28 was expressed across all developmental leaf stages, with higher transcript accumulation in mature and inflorescence leaves. Over-expression and RNAi studies showed that BoaMYB28 retains the basic MYB28 gene function as a major transcriptional regulator of aliphatic glucosinolate pathway. The results indicated that over-expression and RNAi lines showed no visible difference on plant morphology. The contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes increased in over-expression lines and decreased in RNAi lines. In over-expression lines, aliphatic glucosinolate contents were 1.5- to 3-fold higher than those in the wild-type, while expression levels of aliphatic glucosinolate biosynthesis genes were 1.5- to 4-fold higher than those in the wild-type. In contrast, the contents of aliphatic glucosinolates and transcript levels of aliphatic glucosinolate biosynthesis genes in

Aliphatic alcohols of illegally produced spirits can act synergistically on superoxide-anion production by human granulocytes.

Science.gov (United States)

Arnyas, Ervin M; Pál, László; Kovács, Csilla; Adány, Róza; McKee, Martin; Szűcs, Sándor

2012-10-01

Aliphatic alcohols present in illegally produced spirits in a large number of low and middle income countries have been implicated in the etiology of chronic liver disease and cirrhosis. Previous studies have confirmed that chronic alcoholism can lead to increased susceptibility to infectious diseases. Reduced superoxide-anion (O(2)·(-)) production by granulocytes could provide a mechanism by which antimicrobial defense is impaired in alcoholics. In vitro experiments have also demonstrated that ethanol can inhibit granulocyte O(2)·(-) generation. Aliphatic alcohols consumed as contaminants of illicit spirits may also influence O(2)·(-) production thereby contributing to a decrease in microbicidal activity. The aim of this study was to investigate this possibility. It measured the O(2)·(-) production by human granulocytes following treatment of the cells with aliphatic alcohol contaminants found in illicit spirits. Granulocytes were isolated from human buffy coats with centrifugal elutriation and then treated with individual aliphatic alcohols and their mixture. The O(2)·(-) production was stimulated with phorbol-12-13-dibutyrate and N-formyl-methionyl-leucyl-phenylalanine (FMLP) and measured by superoxide dismutase inhibitable reduction of ferricytochrome c. Aliphatic alcohols of illegally produced spirits inhibited the FMLP-induced O(2)·(-) production in a concentration dependent manner. They suppressed O(2)·(-) generation at 2.5-40 times lower concentrations when combined than when tested individually. Aliphatic alcohols found in illegally produced spirits can inhibit FMLP-induced O(2)·(-) production by granulocytes in a concentration-dependent manner. Due to their synergistic effects, it is possible that, in combination with ethanol, they may inhibit O(2)·(-) formation in heavy episodic drinkers.

Palladium-catalyzed aryl C-H olefination with unactivated, aliphatic alkenes.

Science.gov (United States)

Deb, Arghya; Bag, Sukdev; Kancherla, Rajesh; Maiti, Debabrata

2014-10-01

Palladium-catalyzed coupling between aryl halides and alkenes (Mizoroki-Heck reaction) is one of the most popular reactions for synthesizing complex organic molecules. The limited availability, problematic synthesis, and higher cost of aryl halide precursors (or their equivalents) have encouraged exploration of direct olefination of aryl carbon-hydrogen (C-H) bonds (Fujiwara-Moritani reaction). Despite significant progress, the restricted substrate scope, in particular noncompliance of unactivated aliphatic olefins, has discouraged the use of this greener alternative. Overcoming this serious limitation, we report here a palladium-catalyzed chelation-assisted ortho C-H bond olefination of phenylacetic acid derivatives with unactivated, aliphatic alkenes in good to excellent yields with high regio- and stereoselectivities. The versatility of this operationally simple method has been demonstrated through drug diversification and sequential C-H olefination for synthesizing divinylbenzene derivatives.

Extraction of sulphates by long chain amines

International Nuclear Information System (INIS)

Boirie, Ch.

1959-05-01

The extraction of sulphuric acid by long chain amines in organic solution has been studied with a view to determining the value of the stability constants of the amine sulphates and bi-sulphates formed. We have concentrated chiefly on uranium sulphate and thorium sulphate. The formulae of the complexes extractable with amines have been established, as well as the corresponding dissociation constants. We have observed that for uranium sulphate the formula of the complex depends only on the nature of the amine, whereas for thorium this formula varies with the amine structure. From the formulae determined and the value of the constants calculated, we have been able to establish the best conditions for uranium and thorium extraction and also for a separation of these two elements. Finally we propose an application of this study to the determination of uranium in ores, where the separation of uranium by this method is particularly easy and complete. (author) [fr

Redox reactions of Cu(II)-amine complexes in aqueous solutions

International Nuclear Information System (INIS)

Kumbhar, A.G.; Kishore, Kamal

2003-01-01

A number of amines can be employed for all volatile treatment (AVT) of steam generator (SG) systems of nuclear power reactors. These amines form complexes with Cu 2+ and Ni 2+ ions which come into water due to corrosion. The redox reactions of a number of Cu(II)-AVT amine complexes and the stability of the transient species formed have been studied by pulse radiolysis technique. Rate constants for the reaction of e aq - with a number of Cu(II)-amine complexes have been determined by following the decay of e aq - absorption. Stability of Cu(I)-amine complexes was studied by following the kinetics of the bleaching signal formed at the λ max of the Cu(II) amine complex. Except for Cu(I)-triethanolamine complex all other Cu(I)-amine complexes were found to be stable. One-electron oxidation of Cu(II) amine complexes was studied using azidyl radicals for the oxidation reaction as OH radicals react with the alcohol groups present in the amines used in this study. Cu(III)-amine complexes were found to be unstable and decayed by second-order kinetics

Occurrence and Sources of Aliphatic Hydrocarbons in Soils within ...

African Journals Online (AJOL)

ADOWIE PERE

Keywords: Asphalt Plants; Soil; Aliphatic hydrocarbons; Pristane; Phytane. Hot mix asphalt (HMA) plant is an assemblage of mechanical equipment where aggregates or inert mineral materials such as sand, gravel, crushed stones, Slag, rock dust or powder are blended, heated, dried and mixed with bitumen in measured ...

Reductive amination with zinc powder in aqueous media

Directory of Open Access Journals (Sweden)

Giovanni B. Giovenzana

2011-08-01

Full Text Available Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

Synthesis, docking and in-vitro screening of mannich bases of thiosemicarbazide for anti-fungal activity

Directory of Open Access Journals (Sweden)

Sachin A. Pishawikar

2017-05-01

Analogs with aromatic and substituted aromatic aldehydes showed least activity, while analogs with aliphatic aldehyde, ketones and amines showed greater activity in C. albicans compared to A. niger. Analogs having morpholine as amine showed comparable activity in both. Compounds K17, K18, K19, and K20 have shown comparable highest activities.

Aracyl triflates for preparing fluorescent and UV absorbing derivatives of unreactive carboxylates, amines and other metabolites

Energy Technology Data Exchange (ETDEWEB)

Storer, Malina K. [Biochemistry Unit, Canterbury Health Laboratories, P.O. Box 151, Christchurch (New Zealand); Department of Pathology, Christchurch School of Medicine and Health Sciences, University of Otago, Christchurch (New Zealand); Lever, Michael [Biochemistry Unit, Canterbury Health Laboratories, P.O. Box 151, Christchurch (New Zealand) and Department of Pathology, Christchurch School of Medicine and Health Sciences, University of Otago, Christchurch (New Zealand)]. E-mail: michael.lever@chmeds.ac.nz

2006-02-03

Aracyl trifluoromethanesulfonate (triflate) reagents alkylate the unreactive carboxyl groups of betaines. The reagents also derivatise tertiary amines, amine oxides, phosphates and thioethers. A general derivatisation procedure is to dilute the sample with a polar aprotic organic solvent containing a trace of water, followed by adding an appropriate base and the aracyl triflate reagent. Limits of detection were 40 nM for glycine betaine (GB) and carnitine, 0.14 {mu}M for N,N-dimethylglycine, 70 nM for trimethylamine (TMA), and 5.9 {mu}M trimethylamine-N-oxide (TMAO). Limits of detection were improved when derivatisation yield was optimised for different analytes by changing solvent, base and water content of the reaction mixture. Solvents used include acetonitrile, acetone, butanone, dimethoxyethane and dimethoxyethyl ether, with the presence of some water or alcohol tolerated. Suitable bases include the inorganic bases magnesium hydroxide, silver oxide and lithium phosphate. These bases are sparingly soluble in the reaction solvent so sustain weakly basic conditions during derivatisation and can be removed by centrifugation to stop the reaction. This is particularly important for betaine assays since the derivatives are base-sensitive. The information presented here can be used to develop assays for many metabolites using these versatile reagents.

Aracyl triflates for preparing fluorescent and UV absorbing derivatives of unreactive carboxylates, amines and other metabolites

International Nuclear Information System (INIS)

Storer, Malina K.; Lever, Michael

2006-01-01

Aracyl trifluoromethanesulfonate (triflate) reagents alkylate the unreactive carboxyl groups of betaines. The reagents also derivatise tertiary amines, amine oxides, phosphates and thioethers. A general derivatisation procedure is to dilute the sample with a polar aprotic organic solvent containing a trace of water, followed by adding an appropriate base and the aracyl triflate reagent. Limits of detection were 40 nM for glycine betaine (GB) and carnitine, 0.14 μM for N,N-dimethylglycine, 70 nM for trimethylamine (TMA), and 5.9 μM trimethylamine-N-oxide (TMAO). Limits of detection were improved when derivatisation yield was optimised for different analytes by changing solvent, base and water content of the reaction mixture. Solvents used include acetonitrile, acetone, butanone, dimethoxyethane and dimethoxyethyl ether, with the presence of some water or alcohol tolerated. Suitable bases include the inorganic bases magnesium hydroxide, silver oxide and lithium phosphate. These bases are sparingly soluble in the reaction solvent so sustain weakly basic conditions during derivatisation and can be removed by centrifugation to stop the reaction. This is particularly important for betaine assays since the derivatives are base-sensitive. The information presented here can be used to develop assays for many metabolites using these versatile reagents

Trace Amines and the Trace Amine-Associated Receptor 1: Pharmacology, Neurochemistry and Clinical Implications

Directory of Open Access Journals (Sweden)

Yue ePei

2016-04-01

Full Text Available Biogenic amines are a collection of endogenous molecules that play pivotal roles as neurotransmitters and hormones. In addition to the classical biogenic amines resulting from decarboxylation of aromatic acids, including dopamine (DA, norepinephrine, epinephrine, serotonin (5-HT and histamine, other biogenic amines, present at much lower concentrations in the central nervous system (CNS, and hence referred to as trace amines (TAs, are now recognized to play significant neurophysiological and behavioural functions. At the turn of the century, the discovery of the trace amine-associated receptor 1 (TAAR1, a phylogenetically conserved G protein-coupled receptor that is responsive to both TAs, such as β-phenylethylamine, octopamine and tyramine, and structurally-related amphetamines, unveiled mechanisms of action for TAs other than interference with aminergic pathways, laying the foundations for deciphering the functional significance of TAs and its mammalian CNS receptor, TAAR1. Although its molecular interactions and downstream targets have not been fully elucidated, TAAR1 activation triggers accumulation of intracellular cAMP, modulates PKA and PKC signalling and interferes with the β-arrestin2-dependent pathway via G protein-independent mechanisms. TAAR1 is uniquely positioned to exert direct control over DA and 5-HT neuronal firing and release, which has profound implications for understanding the pathophysiology of, and therefore designing more efficacious therapeutic interventions for, a range of neuropsychiatric disorders that involve aminergic dysregulation, including Parkinson’s disease, schizophrenia, mood disorders and addiction. Indeed, the recent development of novel pharmacological tools targeting TAAR1 has uncovered the remarkable potential of TAAR1-based medications as new generation pharmacotherapies in neuropsychiatry. This review summarizes recent developments in the study of TAs and TAAR1, their intricate neurochemistry and

Tunable, chemoselective amination via silver catalysis.

Science.gov (United States)

Rigoli, Jared W; Weatherly, Cale D; Alderson, Juliet M; Vo, Brian T; Schomaker, Jennifer M

2013-11-20

Organic N-containing compounds, including amines, are essential components of many biologically and pharmaceutically important molecules. One strategy for introducing nitrogen into substrates with multiple reactive bonds is to insert a monovalent N fragment (nitrene or nitrenoid) into a C-H bond or add it directly to a C═C bond. However, it has been challenging to develop well-defined catalysts capable of promoting predictable and chemoselective aminations solely through reagent control. Herein, we report remarkable chemoselective aminations that employ a single metal (Ag) and a single ligand (phenanthroline) to promote either aziridination or C-H insertion by manipulating the coordination geometry of the active catalysts.

An additive for a petroleum coke and water suspension

Energy Technology Data Exchange (ETDEWEB)

Khiguti, K.; Igarasi, T.; Isimura, Y.; Kharaguti, S.; Tsudzina, T.

1983-03-04

The patent covers an additive for a petroleum coke and watersuspension which contains soap of an aliphatic acid (AM) and or a salt of a maleic acid copolymer (SMK). The aliphatic acid soap is a salt of an alkaline earth metal of C6 to C22 aliphatic acid, an ammonium salt or a salt of a lower amine. The maleic acid copolymer is a salt (sodium, NH4) of a lower amine of a maleic anhydride copolymer with a copolymerizing vinyl additive. Capric acid, lauric acid, palmatic acid, aleic and other acids may be used as the aliphatic acid, while methylamine, trimethylamine, diethanolamine, morpholine and so on may be used as the lower amine salt. Ethylene, vinylchloride, methyl(meta)acrylate and so on are used as the polymerizing vinyl compound. The molar ratio of the maleic anhydride to the polymerizing vinyl compound is in a range from 1 to 1 to 1 to 10 (preferably 1 to 1 to 1 to 3). The maleic acid copolymer has a mean molecular mass within 1,000 to 5,000. The additive with the optimal composition contains a solvent, a thickener, an anticorrosion substance, anticoagulants, surfacants (PAV) and so on. A highly concentrated suspension of oil coke and water with a 50 to 75 percent concentration of powder form petroleum coke may be produced using the patented additive. Such a suspension is characterized by low viscosity, high stability and forms no foam during processing.

CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis.

Science.gov (United States)

Chen, Sixue; Glawischnig, Erich; Jørgensen, Kirsten; Naur, Peter; Jørgensen, Bodil; Olsen, Carl-Erik; Hansen, Carsten H; Rasmussen, Hasse; Pickett, John A; Halkier, Barbara A

2003-03-01

Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer-preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant CYP79F1 and CYP79F2 expressed in Escherichia coli and Saccharomyces cerevisiae, respectively, we show that CYP79F1 metabolizes mono- to hexahomomethionine, resulting in both short- and long-chain aliphatic glucosinolates. In contrast, CYP79F2 exclusively metabolizes long-chain elongated penta- and hexahomomethionines. CYP79F1 and CYP79F2 are spatially and developmentally regulated, with different gene expression patterns. CYP79F2 is highly expressed in hypocotyl and roots, whereas CYP79F1 is strongly expressed in cotyledons, rosette leaves, stems, and siliques. A transposon-tagged CYP79F1 knockout mutant completely lacks short-chain aliphatic glucosinolates, but has an increased level of long-chain aliphatic glucosinolates, especially in leaves and seeds. The level of long-chain aliphatic glucosinolates in a transposon-tagged CYP79F2 knockout mutant is substantially reduced, whereas the level of short-chain aliphatic glucosinolates is not affected. Biochemical characterization of CYP79F1 and CYP79F2, and gene expression analysis, combined with glucosinolate profiling of knockout mutants demonstrate the functional role of these enzymes. This provides valuable insights into the metabolic network leading to the biosynthesis of aliphatic glucosinolates, and into metabolic engineering of altered aliphatic glucosinolate profiles to improve nutritional value and pest resistance.

Kinetics of Oxidation of Aliphatic Alcohols by Potassium Dichromate ...

African Journals Online (AJOL)

The kinetics of oxidation of four aliphatic alcohols in acidic aqueous and micellar media were investigated. The reaction was found to be first-order with respect to both alcohol and oxidant. Pseudo-first-order kinetics were found to be perfectly applicable with ethanol, 1-propanol and 2-propanol while deviation was observed ...

Development of I-123-labeled amines for brain studies: localization of I-123 iodophenylalkyl amines in rat brain

International Nuclear Information System (INIS)

Winchell, H.S.; Baldwin, R.M.; Lin, T.H.

1980-01-01

Localization in rat brain of forty iodophenylalkyl amines labeled with I-123 was evaluated in an attempt to develop I-123-labeled amines useful for brain studies. For the amines studied, the highest activity in brain and the brain-to-blood activity ratios ranked p > m > o as related to iodine position on the benzene ring: for alkyl groups the rank order was α-methylethyl > ethyl > methyl > none; for N additions it was single lipophilic group > H > two lipophilic groups. It is suggested that introduction of a halogen into the ring structure of many amines results in greater concentration of the agent in brain than is seen with the nonhalogenated parent compound. The agent N-isopropyl-p-iodoamphetamine was chosen for further study because, in the rat, it showed high brain activity (1.57%/g) and brain-blood ratio (12.6) at 5 min

Modification of Aliphatic Petroleum Resin by Peracetic Acid

OpenAIRE

Bondaletov, Vladimir Grigoryevich; Bondaletova, Lyudmila Ivanovna; Hamlenko, A.; Bondaletov, Oleg Vladimirovich; Starovoit, M.

2014-01-01

This work demonstrates the possibility of obtaining modified aliphatic resin (PRC5) by means of petroleum resin oxidation by peracetic acid. We have experimentally determined oxidation conditions that lead to producing resin with maximum epoxy and acid numbers. Ratio of "oxidative system: PRC5" is 0.5:1, process duration is 2 hours. The modified resin structure is determined by IR and NMR spectroscopy.

Kinetics and mechanism of oxidation of aliphatic primary alcohols by ...

Indian Academy of Sciences (India)

Unknown

Kinetics and mechanism of oxidation of aliphatic primary alcohols by quinolinium bromochromate. SONU SARASWAT, VINITA SHARMA and K K BANERJI*. Department of Chemistry, JNV University, Jodhpur 342 005, India e-mail: banerjikk@rediffmail.com. MS received 4 December 2001; revised 2 November 2002.

New insights into controlling tube-bundle fouling using alternative amines

Energy Technology Data Exchange (ETDEWEB)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K. [Atomic Energy of Canada Ltd. (Canada); Frattini, P.L. [Electric Power Research Inst. (United States)

2002-07-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

New insights into controlling tube-bundle fouling using alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Fruzzetti, K.; Frattini, P.L.

2002-01-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of deposit consolidation result in a low rate of deposit removal and a high fouling rate. Conversely, amines that tend to inhibit deposit consolidation produce a higher rate of deposit removal and a lower fouling rate. Dimethyl-amine and dodecyl-amine have been identified as two amines that inhibit the rate of deposit consolidation and, consequently, result in fouling rates that are up to 5 times lower than rates measured for amines that promote consolidation. A significant difference between morpholine (high fouling rate) and dimethyl-amine (low fouling rate) is that the latter desorbs more slowly from the surface of magnetite. How to account for a correlation between slow desorption kinetics and lower rate constants for deposition and

A systems biology approach identifies a R2R3 MYB gene subfamily with distinct and overlapping functions in regulation of aliphatic glucosinolates.

Directory of Open Access Journals (Sweden)

Ida Elken Sønderby

Full Text Available BACKGROUND: Glucosinolates are natural metabolites in the order Brassicales that defend plants against both herbivores and pathogens and can attract specialized insects. Knowledge about the genes controlling glucosinolate regulation is limited. Here, we identify three R2R3 MYB transcription factors regulating aliphatic glucosinolate biosynthesis in Arabidopsis by combining several systems biology tools. METHODOLOGY/PRINCIPAL FINDINGS: MYB28 was identified as a candidate regulator of aliphatic glucosinolates based on its co-localization within a genomic region controlling variation both in aliphatic glucosinolate content (metabolite QTL and in transcript level for genes involved in the biosynthesis of aliphatic glucosinolates (expression QTL, as well as its co-expression with genes in aliphatic glucosinolate biosynthesis. A phylogenetic analysis with the R2R3 motif of MYB28 showed that it and two homologues, MYB29 and MYB76, were members of an Arabidopsis-specific clade that included three characterized regulators of indole glucosinolates. Over-expression of the individual MYB genes showed that they all had the capacity to increase the production of aliphatic glucosinolates in leaves and seeds and induce gene expression of aliphatic biosynthetic genes within leaves. Analysis of leaves and seeds of single knockout mutants showed that mutants of MYB29 and MYB76 have reductions in only short-chained aliphatic glucosinolates whereas a mutant in MYB28 has reductions in both short- and long-chained aliphatic glucosinolates. Furthermore, analysis of a double knockout in MYB28 and MYB29 identified an emergent property of the system since the absence of aliphatic glucosinolates in these plants could not be predicted by the chemotype of the single knockouts. CONCLUSIONS/SIGNIFICANCE: It seems that these cruciferous-specific MYB regulatory genes have evolved both overlapping and specific regulatory capacities. This provides a unique system within which to

Hydrodeoxygenation of aliphatic and aromatic oxygenates on sulphided catalysts for production of second generation biofuels

Energy Technology Data Exchange (ETDEWEB)

Senol, O.I.

2007-07-01

Environmental concerns and diminishing petroleum reserves have increased the importance of biofuels for traffic fuel applications. Second generation biofuels produced from wood, vegetable oils and animal fats have been considered promising for delivering biofuels in large amount with low production cost. The abundance of oxygen in the form of various aliphatic and aromatic oxygenates decreases the quality of biofuels, however, and therefore the oxygen content of biofuels must be reduced. Upgrading of biofuels can be achieved by hydrodeoxygenation (HDO), which is similar to hydrodesulphurisation in oil refining. In HDO, oxygen-containing compounds are converted to hydrocarbons by eliminating oxygen in the form of water in the presence of hydrogen and a sulphided catalyst. Due to the low sulphur content of biofuels, a sulphiding agent is typically added to the HDO feed to maintain activity and stability of the catalyst. The aim of this work was to investigate HDO using aliphatic and aromatic oxygenates as model compounds on sulphided NiMo/gamma-Al{sub 2}O3 and CoMo/gamma-Al{sub 2}O3 catalysts. The effects of side product, water, and of sulphiding agents, H{sub 2}S and CS{sub 2}, on HDO were determined. The primary focus was on the HDO of aliphatic oxygenates, because a reasonable amount of data regarding the HDO of aromatic oxygenates already exists. The HDO of aliphatic esters produced hydrocarbons from intermediate alcohol, carboxylic acid, aldehyde and ether compounds. A few sulphur-containing compounds were also detected in trace amounts, and their formation caused desulphurisation of the catalysts. Hydrogenation reactions and acid-catalysed reactions (dehydration, hydrolysis, esterification, E{sub 2} elimination and SN{sub 2} nucleophilic substitution) played a major role in the HDO of aliphatic oxygenates. The NiMo catalyst showed a higher activity for HDO and hydrogenation reactions than the CoMo catalyst, but both catalysts became deactivated because of

BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

Directory of Open Access Journals (Sweden)

Attila Kántor

2015-02-01

Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

Biogenic amine formation and bacterial contribution in Natto products.

Science.gov (United States)

Kim, Bitna; Byun, Bo Young; Mah, Jae-Hyung

2012-12-01

Twenty-one Natto products currently distributed in Korea were analysed for biogenic amine contents and tested to determine physicochemical and bacterial contributions to biogenic amine formation. Among them, nine products (about 43%) had β-phenylethylamine or tyramine contents greater than the toxic dose (30mg/kg and 100mg/kg, respectively) of each amine, although no products showed total amounts of biogenic amines above the harmful level (1000mg/kg), which indicates that the amounts of biogenic amines in some Natto products are not within the safe level for human health. From four different Natto products, that contained noticeable levels of β-phenylethylamine and tyramine, 80 bacterial strains were isolated. All the strains were identified to be Bacillus subtilis and highly capable of producing β-phenylethylamine and tyramine. Therefore, it seems likely that the remarkable contents of β-phenylethylamine and tyramine in Natto predominantly resulted from the strains highly capable of producing those amines present in the food. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sodium Perborate Oxidation of an Aromatic Amine

Science.gov (United States)

Juestis, Laurence

1977-01-01

Describes an experiment involving the oxidation of aromatic primary amines to the corresponding azo compound; suggests procedures for studying factors that influence the yield of such a reaction, including the choice of solvent and the oxidant-amine ratio. (MLH)

A Catalyst-Free Amination of Functional Organolithium Reagents by Flow Chemistry.

Science.gov (United States)

Kim, Heejin; Yonekura, Yuya; Yoshida, Jun-Ichi

2018-04-03

Reported is the electrophilic amination of functional organolithium intermediates with well-designed aminating reagents under mild reaction conditions using flow microreactors. The aminating reagents were optimized to achieve efficient C-N bond formation without using any catalyst. The electrophilic amination reactions of functionalized aryllithiums were successfully conducted under mild reaction conditions, within 1 minute, by using flow microreactors. The aminating reagent was also prepared by the flow method. Based on stopped-flow NMR analysis, the reaction time for the preparation of the aminating reagent was quickly optimized without the necessity of work-up. Integrated one-flow synthesis consisting of the generation of an aryllithium, the preparation of an aminating reagent, and their combined reaction was successfully achieved to give the desired amine within 5 minutes of total reaction time. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aliphatic-aromatic separation using deep eutectic solvents as extracting agents

NARCIS (Netherlands)

Rodriguez Rodriguez, Nerea; Fernandez Requejo, Patricia; Kroon, Maaike

2015-01-01

The separation of aliphatic and aromatic compounds is a great challenge for chemical engineers. There is no efficient separation process for mixtures with compositions lower than 20 wt % in aromatics. In this work, the feasibility of two different deep eutectic solvents (DESs) as novel extracting

The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

Science.gov (United States)

Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

2017-06-01

Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

Dual C-H functionalization of N-aryl amines: synthesis of polycyclic amines via an oxidative Povarov approach.

Science.gov (United States)

Min, Chang; Sanchawala, Abbas; Seidel, Daniel

2014-05-16

Iminium ions generated in situ via copper(I) bromide catalyzed oxidation of N-aryl amines readily undergo [4 + 2] cycloadditions with a range of dienophiles. This method involves the functionalization of both a C(sp(3))-H and a C(sp(2))-H bond and enables the rapid construction of polycyclic amines under relatively mild conditions.

Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

KAUST Repository

Yue, Huifeng

2017-03-15

An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

Transition Metal Free C-N Bond Forming Dearomatizations and Aryl C-H Aminations by in Situ Release of a Hydroxylamine-Based Aminating Agent.

Science.gov (United States)

Farndon, Joshua J; Ma, Xiaofeng; Bower, John F

2017-10-11

We outline a simple protocol that accesses directly unprotected secondary amines by intramolecular C-N bond forming dearomatization or aryl C-H amination. The method is dependent on the generation of a potent electrophilic aminating agent released by in situ deprotection of O-Ts activated N-Boc hydroxylamines.

Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C−O and C−C Bond Activation

KAUST Repository

Yue, Huifeng; Guo, Lin; Liao, Hsuan-Hung; Cai, Yunfei; Zhu, Chen; Rueping, Magnus

2017-01-01

An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.

Intolerance to dietary biogenic amines: A review

NARCIS (Netherlands)

Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

2003-01-01

Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

Intolerance to dietary biogenic amines : a review

NARCIS (Netherlands)

Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

In vitro evaluation of aliphatic fatty alcohol metabolites of ...

African Journals Online (AJOL)

From the seeds of P. americana, five known 1, 2, 4-dihydroxy derivatives aliphatic alcohols, called avocadenols were isolated and identified by spectroscopic methodsincluding 1D- and 2D NMR, and comparison with reported data in literature. Antifungal activity for 1, 2, 4-Trihydroxyheptadec-6-en-16-yne (5)(IC50< 8 μg/mL) ...

Analysis of a Buchwald-Hartwig amination: reaction for pharmaceutical production

DEFF Research Database (Denmark)

Christensen, Henrik

The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

Analysis of a Buckwald-Hartwig amination: reaction for pharmaceutical production

DEFF Research Database (Denmark)

Christensen, Henrik; Kiil, Søren; Dam-Johansen, Kim

The Buchwald-Hartwig amination reaction is widely used in the production of N-arylated amines in the pharmaceutical industry. The reaction is betweenan aryl halogen and a primary or secondary amine in the presence of a base and a homogeneous catalyst giving the desired N-arylated amine. Due to mild...... is to increase the understanding of the chem­ical reaction mechanisms and kinetics for the Buchwald-Hartwig amination reaction. Also, to develop methods for application of these mechanisms and kinetics to optimize and scale up an organic synthesis to an industrial phar­maceutical production. The Buchwald...

Vapor Pressure of Selected Aliphatic Alcohols by Ebulliometry. Part 1

Czech Academy of Sciences Publication Activity Database

Čenský, M.; Roháč, V.; Růžička, K.; Fulem, M.; Aim, Karel

2010-01-01

Roč. 298, č. 2 (2010), s. 192-198 ISSN 0378-3812 R&D Projects: GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : vapor pressure * ebulliometry * aliphatic alcohols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.253, year: 2010

Functional electrospun nanofibers for multimodal sensitive detection of biogenic amines in food via a simple dipstick assay.

Science.gov (United States)

Yurova, Nadezhda S; Danchuk, Alexandra; Mobarez, Sarah N; Wongkaew, Nongnoot; Rusanova, Tatiana; Baeumner, Antje J; Duerkop, Axel

2018-01-01

Electrospun nanofibers (ENFs) are promising materials for rapid diagnostic tests like lateral flow assays and dipsticks because they offer an immense surface area while excluding minimal volume, a variety of functional surface groups, and can entrap functional additives within their interior. Here, we show that ENFs on sample pads are superior in comparison to standard polymer membranes for the optical detection of biogenic amines (BAs) in food using a dipstick format. Specifically, cellulose acetate (CA) fibers doped with 2 mg/mL of the chromogenic and fluorogenic amine-reactive chameleon dye Py-1 were electrospun into uniform anionic mats. Those extract cationic BAs from real samples and Py-1 transduces BA concentrations into a change of color, reflectance, and fluorescence. Dropping a BA sample onto the nanofiber mat converts the weakly fluorescent pyrylium dye Py-1 into a strongly red emitting pyridinium dye. For the first time, a simple UV lamp excites fluorescence and a digital camera acts as detector. The intensity ratio of the red to the blue channel of the digital image is dependent on the concentration of most relevant BAs indicating food spoilage from 10 to 250 μM. This matches the permitted limits for BAs in foods and no false positive signals arise from secondary and tertiary amines. BA detection in seafood samples was also demonstrated successfully. The nanofiber mat dipsticks were up to sixfold more sensitive than those using a polymer membrane with the same dye embedded. Hence, nanofiber-based tests are not only superior to polymer-based dipstick assays, but will also improve the performance of established tests related to food safety, medical diagnostics, and environmental testing. Graphical Absract ᅟ.

Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

Science.gov (United States)

Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

2013-11-10

Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

Directory of Open Access Journals (Sweden)

Valerie Vranova

2013-01-01

Full Text Available Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research.

Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

Science.gov (United States)

Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

2013-01-01

Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

Fluorinated Amine Stereotriads via Allene Amination.

Science.gov (United States)

Liu, Lu; Gerstner, Nels C; Oxtoby, Lucas J; Guzei, Ilia A; Schomaker, Jennifer M

2017-06-16

The incorporation of fluorine into organic scaffolds often improves the bioactivity of pharmaceutically relevant compounds. C-F/C-N/C-O stereotriad motifs are prevalent in antivirals, neuraminidase inhibitors, and modulators of androgen receptors, but are challenging to install. An oxidative allene amination strategy using Selectfluor rapidly delivers triply functionalized triads of the form C-F/C-N/C-O, exhibiting good scope and diastereoselectivity for all syn products. The resulting stereotriads are readily transformed into fluorinated pyrrolidines and protected α-, β-, and γ-amino acids.

Bulk gold catalyzed oxidation reactions of amines and isocyanides and iron porphyrin catalyzed N-H and O-H bond insertion/cyclization reactions of diamines and aminoalcohols

Energy Technology Data Exchange (ETDEWEB)

Klobukowski, Erik [Iowa State Univ., Ames, IA (United States)

2011-01-01

conditions, it was found that the oxidative dehydrogenation of dibenzylamine to Nbenzylidenebenzylamine, with N-methylmorpholine N-oxide (NMMO), was nearly quantitative (96%) within 24 h. However, the reaction with oxygen was much slower, with only a 52% yield of imine product over the same time period. Moreover, the rate of reaction was found to be influenced by the nature of the amine N-oxide. For example, the use of the weakly basic pyridine N-oxide (PyNO) led to an imine yield of only 6% after 24 h. A comparison of amine N-oxide and O2 was also examined in the oxidation of PhCH{sub 2}OH to PhCHO catalyzed by bulk gold. In this reaction, a 52% yield of the aldehyde was achieved when NMMO was used, while only a 7% product yield was afforded when O{sub 2} was the oxidant after 48 h. The bulk gold-catalyzed oxidative dehydrogenation of cyclic amines generates amidines, which upon treatment with Aerosil and water were found to undergo hydrolysis to produce lactams. Moreover, 5-, 6-, and 7-membered lactams could be prepared through a one-pot reaction of cyclic amines by treatment with oxygen, water, bulk gold, and Aerosil. This method is much more atom economical than industrial processes, does not require corrosive acids, and does not generate undesired byproducts. Additionally, the gold and Aerosil catalysts can be readily separated from the reaction mixture. The second project involved studying iron(III) tetraphenylporphyrin chloride, Fe(TPP)Cl, as a homogeneous catalyst for the generation of carbenes from diazo reagents and their reaction with heteroatom compounds. Fe(TPP)Cl, efficiently catalyzed the insertion of carbenes derived from methyl 2-phenyldiazoacetates into O-H bonds of aliphatic and aromatic alcohols. Fe(TPP)Cl was also found to be an effective catalyst for tandem N-H and O-H insertion/cyclization reactions when 1,2-diamines and 1,2-alcoholamines were treated with diazo reagents. This approach provides a one-pot process for synthesizing piperazinones and

Evaluation of amine inhibitors for suitability as crevice buffering agents

International Nuclear Information System (INIS)

Jayaweera, P.; Hettiarachchi, S.

1994-03-01

This report describes the results of a research effort to evaluate the suitability of some selected amines and amino acids as a crevice-buffering agents in pressurized water reactor (PWR) steam generators. The amines may be useful for buffering acid crevices, and the amino acids, because they contain both acidic and basic groups, may be useful for acidic and caustic crevices. Five commercially available amines and two amino acids were studied during this research. The study involved (1) the hydrolysis of these commercially available amines and amino acids, including measurement of their kinetics of decomposition, in simulated steam generator bulk water at 290 C, and (2) determination of their thermal stability in a simulated crevice environment. The study showed that, although the high-molecular-weight amines undergo hydrothermal decomposition, they have a better buffering capacity than their low-molecular-weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the crevice solution by as much as 2.84 and to 4.24 units in the experimental setup used in this program. It was concluded that polyamines provide excellent buffering of the simulated crevice environment at 290 C and morpholine remains the best low-molecular-weight amine investigated. However, detailed volatility studies of the amines were not considered in this work. Such data would be needed before in-plant testing to ensure that the amines can concentrate in steam generator crevices to the levels assumed in this study

In vivo genotoxicity of nitramines, transformation products of amine-based carbon capture technology

Directory of Open Access Journals (Sweden)

Claire Coutris

2015-05-01

Full Text Available In times where we need to reduce our CO2 emissions to the atmosphere, it is important to get a clearer picture of the environmental impacts associated with potential mitigation technologies. Chemical absorption with amines is emerging as the most advanced mitigation technology for post-combustion capture of CO2 from fossil fuel power stations. Although the amine solvent used in this technology is recycled during the capture process, degradation products are formed and released into the environment. Among these degradation products, the aliphatic nitramine compounds dimethylnitramine and ethanolnitramine have been identified, whose environmental impact was unknown. In addition to conducting survival, growth and reproduction tests in a range of marine species, we looked into the in vivo genotoxic potential of these two compounds to experimentally exposed fish (Coutris et al. 2015. DNA damage was analyzed in blood samples collected from the caudal vein of juvenile turbot Scophthalmus maximus after 28 day exposure to nitramines, using the 12 mini-gels version of the comet assay, with and without digestion with formamidopyrimidine DNA glycosylase. Although whole organism bioassays indicated that nitramine toxicity through necrosis was low, the genotoxicity assessment revealed contrasting results, with ethanolnitramine found to be more genotoxic than dimethylnitramine by three orders of magnitude. At the lowest ethanolnitramine concentration (1 mg/L, 84 % DNA damage was observed, whereas 100 mg/L dimethylnitramine was required to cause 37 % DNA damage. The mechanisms of genotoxicity were also shown to differ between the two compounds, with oxidation of the DNA bases responsible for over 90 % of the genotoxicity of dimethylnitramine, whereas DNA strand breaks and alkali-labile sites were responsible for over 90 % of the genotoxicity of ethanolnitramine. Fish exposed to > 3 mg/L ethanolnitramine had virtually no DNA left in their red blood cells. The

Chlorinated aliphatic and aromatic VOC decomposition in air mixture by using electron beam irradiation

International Nuclear Information System (INIS)

Chmielewski, A.G.; Sun Yongxia; Bulka, S.; Zimek, Z.

2004-01-01

Chlorinated aliphatic and aromatic hydrocarbons, which are emitted from coal power station and waste incinerators, are very harmful to the environment and human health. Recent studies show that chlorinated aliphatic and aromatic hydrocarbons are suspected to be the precursors of dioxin's formation. Dioxin's emission into atmosphere will cause severe environmental problems by ecology contamination. l,4-dichlorobenzene(l,4-DCB) and cis-dichloroethylene(cis-DCE) were chosen as representative chlorinated aromatic and aliphatic compounds, respectively. Their decomposition was investigated by electron beam irradiation. The experiments were carried out 'in batch' system. It is found that over 97% cis-DCE is decomposed having an initial concentration of 661 ppm. G-values of cis-DCE decomposition vary from 10 to 28 (molecules/100 eV) for initial concentration of 270-1530 ppm cis-DCE. The decomposition is mainly caused by secondary electron attachment and Cl addition reactions. Comparing with cis-DCE, 1,4-DCB decomposition needs higher absorbed dose. G-value of 1,4-DCB is below 4 molecules/100 eV

Poly(Amido Amine)s Containing Agmatine and Butanol Side Chains as Efficient Gene Carriers.

Science.gov (United States)

Won, Young-Wook; Ankoné, Marc; Engbersen, Johan F J; Feijen, Jan; Kim, Sung Wan

2016-04-01

A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of ABOL in the side chains have shown to improve the overall transfection efficiency of poly(amido amine)s, it is hypothesized that poly(CBA-ABOL/AGM) synthesized at the optimal ratio of both components would result in high transfection efficiency and minimal toxicity. In this study, a series of the poly(CBA-ABOL/AGM) copolymers is synthesized as gene carriers. The polymers are characterized and luciferase transfection efficiencies of the polymers in various cell lines are investigated to select the ideal ratio between AGM and ABOL. The poly(CBA-ABOL/AGM) containing 80% AGM and 20% ABOL has shown the best transfection efficiency with the lowest cytotoxicity, indicating that this polymer is very promising as a potent and nontoxic gene carrier. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fluorescence quenching of Rhodamine B base by two amines

Science.gov (United States)

Bakkialakshmi, S.; Selvarani, P.; Chenthamarai, S.

2013-03-01

Fluorescence quenching of Rhodamine B base (RhB) in DMF solution has been studied at different concentrations of the amine Triethyl amine (TEA) and n-butyl amine (NBA) at room temperature. It has been observed that the fluorescence intensity of RhB decrease with increase in the concentration of the TEA and NBA. It has been observed that the quenching due to amines proceeds via dynamic quenching process. The rate constants for the quenching process have been calculated using Stern-Volmer equation. Time resolved fluorescence study and 1H NMR spectral study have also been carried out and discussed.

Enzymatic degradation of aliphatic nitriles by Rhodococcus rhodochrous BX2, a versatile nitrile-degrading bacterium.

Science.gov (United States)

Fang, Shumei; An, Xuejiao; Liu, Hongyuan; Cheng, Yi; Hou, Ning; Feng, Lu; Huang, Xinning; Li, Chunyan

2015-06-01

Nitriles are common environmental pollutants, and their removal has attracted increasing attention. Microbial degradation is considered to be the most acceptable method for removal. In this work, we investigated the biodegradation of three aliphatic nitriles (acetonitrile, acrylonitrile and crotononitrile) by Rhodococcus rhodochrous BX2 and the expression of their corresponding metabolic enzymes. This organism can utilize all three aliphatic nitriles as sole carbon and nitrogen sources, resulting in the complete degradation of these compounds. The degradation kinetics were described using a first-order model. The degradation efficiency was ranked according to t1/2 as follows: acetonitrile>trans-crotononitrile>acrylonitrile>cis-crotononitrile. Only ammonia accumulated following the three nitriles degradation, while amides and carboxylic acids were transient and disappeared by the end of the assay. mRNA expression and enzyme activity indicated that the tested aliphatic nitriles were degraded via both the inducible NHase/amidase and the constitutive nitrilase pathways, with the former most likely preferred. Copyright © 2015 Elsevier Ltd. All rights reserved.

C-11-labeled octadecylamine, a potential agent for positron tomographic pulmonary metabolism studies

International Nuclear Information System (INIS)

Washburn, L.C.; Wallace, R.T.; Byrd, B.L.; Sun, T.T.; Coffey, J.L.; Hubner, K.F.

1984-01-01

C-11-Labeled straight-chain primary aliphatic amines are rapidly and selectively sequestered by lung endothelial cells, making these agents potentially useful for positron tomographic studies of the lung as a metabolic organ. However, because amines having straight chains containing 4 to 13 carbon atoms are rapidly catabolized in vivo with loss of radiolabel, quantitation of pulmonary concentration is difficult. The authors have studied the effect of structural changes on the uptake and retention of primary aliphatic amines in rat lung and found that the metabolic loss form the lung decreased with increasing length of the straight carbon chain. In fact, the lung concentration of octadecylamine, a straight-chain amine with 18 carbon atoms, was constant between 1 and 30 minutes after intravenous administration. This highly insoluble amine was solubilized using 3% aqueous human serum albumin. Unilateral, radiation-induced lung injury in the rat was used as a model to study the potential of C-11-labeled octadecylamine. Radiation-damaged (3000 and 5000 Rads) lungs had significantly lower 15-minute uptakes of the labeled amine than the corresponding nonirradiated lungs. However, at 8000 Rads the concentration in both lungs was greatly suppressed, indicating that the decrease in metabolism becomes systemic at high radiation doses. These results suggest that C-11-labeled octadecylamine is a potentially useful agent for quantitative evaluation of pulmonary metabolism by positron tomography

BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

Directory of Open Access Journals (Sweden)

Radka Flasarová

2012-02-01

Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

Biogenic amines in dry fermented sausages: a review.

Science.gov (United States)

Suzzi, Giovanna; Gardini, Fausto

2003-11-15

Biogenic amines are compounds commonly present in living organisms in which they are responsible for many essential functions. They can be naturally present in many foods such as fruits and vegetables, meat, fish, chocolate and milk, but they can also be produced in high amounts by microorganisms through the activity of amino acid decarboxylases. Excessive consumption of these amines can be of health concern because their not equilibrate assumption in human organism can generate different degrees of diseases determined by their action on nervous, gastric and intestinal systems and blood pressure. High microbial counts, which characterise fermented foods, often unavoidably lead to considerable accumulation of biogenic amines, especially tyramine, 2-phenylethylamine, tryptamine, cadaverine, putrescine and histamine. However, great fluctuations of amine content are reported in the same type of product. These differences depend on many variables: the quali-quantitative composition of microbial microflora, the chemico-physical variables, the hygienic procedure adopted during production, and the availability of precursors. Dry fermented sausages are worldwide diffused fermented meat products that can be a source of biogenic amines. Even in the absence of specific rules and regulations regarding the presence of these compounds in sausages and other fermented products, an increasing attention is given to biogenic amines, especially in relation to the higher number of consumers with enhanced sensitivity to biogenic amines determined by the inhibition of the action of amino oxidases, the enzymes involved in the detoxification of these substances. The aim of this paper is to give an overview on the presence of these compounds in dry fermented sausages and to discuss the most important factors influencing their accumulation. These include process and implicit factors as well as the role of starter and nonstarter microflora growing in the different steps of sausage production

Direct α-C-H bond functionalization of unprotected cyclic amines

Science.gov (United States)

Chen, Weijie; Ma, Longle; Paul, Anirudra; Seidel, Daniel

2018-02-01

Cyclic amines are ubiquitous core structures of bioactive natural products and pharmaceutical drugs. Although the site-selective abstraction of C-H bonds is an attractive strategy for preparing valuable functionalized amines from their readily available parent heterocycles, this approach has largely been limited to substrates that require protection of the amine nitrogen atom. In addition, most methods rely on transition metals and are incompatible with the presence of amine N-H bonds. Here we introduce a protecting-group-free approach for the α-functionalization of cyclic secondary amines. An operationally simple one-pot procedure generates products via a process that involves intermolecular hydride transfer to generate an imine intermediate that is subsequently captured by a nucleophile, such as an alkyl or aryl lithium compound. Reactions are regioselective and stereospecific and enable the rapid preparation of bioactive amines, as exemplified by the facile synthesis of anabasine and (-)-solenopsin A.

Sponges with covalently tethered amines for high-efficiency carbon capture

KAUST Repository

Qi, Genggeng

2014-12-12

© 2014 Macmillan Publishers Limited. All rights reserved. Adsorption using solid amine sorbents is an attractive emerging technology for energy-efficient carbon capture. Current syntheses for solid amine sorbents mainly based on physical impregnation or grafting-to methods (for example, aminosilane-grafting) lead to limited sorbent performance in terms of stability and working capacity, respectively. Here we report a family of solid amine sorbents using a grafting-from synthesis approach and synthesized by cationic polymerization of oxazolines on mesoporous silica. The sorbent with high amount of covalently tethered amines shows fast adsorption rate, high amine efficiency and sorbent capacity well exceeding the highest value reported to date for lowerature carbon dioxide sorbents under simulated flue gas conditions. The demonstrated efficiency of the new amine-immobilization chemistry may open up new avenues in the development of advanced carbon dioxide sorbents, as well as other nitrogen-functionalized systems.

Kinetic isotope effects and aliphatic diazo-compounds

International Nuclear Information System (INIS)

Albery, W.J.; Conway, C.W.; Hall, J.A.

1976-01-01

Results are reported for the variation of the rate of decomposition of ethyl diazomalonate (EDM) and diazomalonate anions with pH and for the deuterium solvent isotope effect for EDM. The shape of the pH profile is explained by successive protonations of the anions. Ethyl diazoacetate is observed as an intermediate in the decomposition of EDM. The degree of proton transfer in the EDM transition state is deduced from the solvent isotope effect and the results together with those for other aliphatic diazo-compounds are discussed in terms of the Marcus theory. (author)

Sequential metabolism of secondary alkyl amines to metabolic-intermediate complexes: opposing roles for the secondary hydroxylamine and primary amine metabolites of desipramine, (s)-fluoxetine, and N-desmethyldiltiazem.

Science.gov (United States)

Hanson, Kelsey L; VandenBrink, Brooke M; Babu, Kantipudi N; Allen, Kyle E; Nelson, Wendel L; Kunze, Kent L

2010-06-01

Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine > primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d(3)-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation.

Biogenic amines and radiosensitivity of solitary cells

International Nuclear Information System (INIS)

Goncharenko, E.N.

1978-01-01

Different stability of cells to ionizing radiation is considered from a position of the ''elevated biochemical radioresistance background'' concept. Experimental evidence presented indicates an important role of endogenic amines (serotonin and histamine) possessing radioprotector properties in the cell radioresistance formation. The concept about their effect as being solely a result of circulatory hypoxia is critically discussed. The experimental results favor the existence of a ''cellular'' component, along with the ''hypoxic'' one, in the mechanism of action of biogenic amines. These compounds can affect the initial stages of peroxide oxidation of lipids, thereby favoring a less intensive oxidation induced by radiation. Biogenic amines can also exert influence on the cyclic nucleotide system

Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

International Nuclear Information System (INIS)

Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

2006-01-01

Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

Potential occupational risk of amines in carbon capture for power generation.

Science.gov (United States)

Gentry, P Robinan; House-Knight, Tamara; Harris, Angela; Greene, Tracy; Campleman, Sharan

2014-08-01

While CO2 capture and storage (CCS) technology has been well studied in terms of its efficacy and cost of implementation, there is limited available data concerning the potential for occupational exposure to amines, mixtures of amines, or degradation of by-products from the CCS process. This paper is a critical review of the available data concerning the potential effects of amines and CCS-degradation by-products. A comprehensive review of the occupational health and safety issues associated with exposure to amines and amine by-products at CCS facilities was performed, along with a review of the regulatory status and guidelines of amines, by-products, and CCS process vapor mixtures. There are no specific guidelines or regulations regarding permissible levels of exposure via air for amines and degradation products that could form atmospheric oxidation of amines released from post-combustion CO2 capture plants. While there has been a worldwide effort to develop legal and regulatory frameworks for CCS, none are directly related to occupational exposures. By-products of alkanolamine degradation may pose the most significant health hazard to workers in CCS facilities, with several aldehydes, amides, nitramines, and nitrosamines classified as either known or potential/possible human carcinogens. The absence of large-scale CCS facilities; absence and unreliability of reported data in the literature from pilot facilities; and proprietary amine blends make it difficult to estimate potential amine exposures and predict formation and exposure to degradation products.

The chemistry of amine radical cations produced by visible light photoredox catalysis

Directory of Open Access Journals (Sweden)

Jie Hu

2013-10-01

Full Text Available Amine radical cations are highly useful reactive intermediates in amine synthesis. They have displayed several modes of reactivity leading to some highly sought-after synthetic intermediates including iminium ions, α-amino radicals, and distonic ions. One appealing method to access amine radical cations is through one-electron oxidation of the corresponding amines under visible light photoredox conditions. This approach and subsequent chemistries are emerging as a powerful tool in amine synthesis. This article reviews synthetic applications of amine radical cations produced by visible light photocatalysis.

Characterization of polyoxyethylene tallow amine surfactants in technical mixtures and glyphosate formulations using ultra-high performance liquid chromatography and triple quadrupole mass spectrometry

Science.gov (United States)

Tush, Daniel; Loftin, Keith A.; Meyer, Michael T.

2013-01-01

Little is known about the occurrence, fate, and effects of the ancillary additives in pesticide formulations. Polyoxyethylene tallow amine (POEA) is a non-ionic surfactant used in many glyphosate formulations, a widely applied herbicide both in agricultural and urban environments. POEA has not been previously well characterized, but has been shown to be toxic to various aquatic organisms. Characterization of technical mixtures using ultra-high performance liquid chromatography (UHPLC) and mass spectrometry shows POEA is a complex combination of homologs of different aliphatic moieties and ranges of ethoxylate units. Tandem mass spectrometry experiments indicate that POEA homologs generate no product ions readily suitable for quantitative analysis due to poor sensitivity. A comparison of multiple high performance liquid chromatography (HPLC) and UHPLC analytical columns indicates that the stationary phase is more important in column selection than other parameters for the separation of POEA. Analysis of several agricultural and household glyphosate formulations confirms that POEA is a common ingredient but ethoxylate distributions among formulations vary.

Cyclohexane/benzene organic glasses and ethylene/styrene copolymers behaviour under ionizing radiations: energy and species transfers between aliphatic and aromatic moieties

International Nuclear Information System (INIS)

Ferry, M.

2008-11-01

The aim of this study is to understand how aliphatic and aromatic groups interact under ionizing radiations. Three research orientations were explored: the determination of the relative contribution of energy and radical transfers, the determination of the intermolecular and intra-chain relative contribution, and the influence of the repartition of the aliphatic and aromatic units inside the polymer chain. Three systems composed of aromatic and aliphatic units were studied: the cyclohexane/benzene organic glasses (intermolecular reactions), the ethylene/styrene random copolymers (inter-chain and intra-chain reactions) and ethylene/styrene di-blocs copolymers (influence of the repartition of the aliphatic and aromatic units in the material). Considering the results obtained, we have concluded that energy transfers are important in the radiation protection effect of the aliphatic moiety by the aromatic one, although radical transfers are also contributing. Intermolecular transfers are efficient in the solid state and their efficiency seems equivalent to that of the intra-chain ones. Thanks to the use of infrared spectroscopy, we have shown an important effect of radiation sensitization of the aromatic moiety, whatever the irradiation temperature and the system studied: energy transfers to the aromatic moiety are carried out at the detriment of its stability. Finally, the repartition of the aliphatic and aromatic units in the polymer chain is not an important factor in the effects induced by the energy transfers. (author)

Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

Science.gov (United States)

Shah, Amisha D; Dai, Ning; Mitch, William A

2013-03-19

Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although amine destruction. Ozone achieved 90% amine removal in washwaters at 5-12 molar excess of ozone, indicating transferred dosage levels of ∼100 mg/L for 90% removal in a first-stage washwater unit, but likely only ∼10 mg/L if applied to a second-stage washwater. Accurate dosage and cost estimates would require pilot testing to capture synergies between UV and ozone treatments.

Swift Heavy Ion Induced Modification of Aliphatic Polymers

OpenAIRE

Hossain, Umme Habiba

2015-01-01

In this thesis, the high energy heavy ion induced modification of aliphatic polymers is studied. Two polymer groups, namely polyvinyl polymers (PVF, PVAc, PVA and PMMA) and fluoropolymers (PVDF, ETFE, PFA and FEP) were used in this work. Polyvinyl polymers were investigated since they will be used as insulating materials in the superconducting magnets of the new ion accelerators of the planned International Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz-Centre of Heavy I...

Mesoporous amine-bridged polysilsesquioxane for CO2 capture

KAUST Repository

Qi, Genggeng; Fu, Liling; Duan, Xiaonan; Choi, Brian Hyun; Abraham, Michael; Giannelis, Emmanuel P.

2011-01-01

A novel class of amine-supported sorbents based on amine-bridged mesoporous polysilsesquioxane was developed via a simple one-pot sol-gel process. The new sorbent allows the incorporation of a large amount of active groups without sacrificing

Enantioselective catalytic syntheses of alpha-branched chiral amines

DEFF Research Database (Denmark)

Brase, S.; Baumann, T.; Dahmen, S.

2007-01-01

Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials.......Chiral amines play a pivotal role in fine chemical and natural product syntheses and the design of novel materials....

Structure and isotopic ratios of aliphatic side chains in the insoluble organic matter of the Murchison carbonaceous chondrite

Science.gov (United States)

Huang, Yongsong; Alexandre, Marcelo R.; Wang, Yi

2007-07-01

We report in this paper the first molecular and isotopic characterization of individual aliphatic side chains from the insoluble organic matter (IOM) in the Murchison carbonaceous chondrite using a novel combined approach of RuO 4 oxidation and solid phase microextraction (SPME). The aliphatic side chains in the IOM of Murchison were first released by oxidizing aromatic structures using RuO 4. Because the IOM of carbonaceous chondrites contains predominantly short (C 1 to C 9) aliphatic substitutions, the resulting low molecular weight monocarboxylic acids (MCAs) are highly volatile and water-soluble. The conventional aqueous extraction and derivatization procedures following RuO 4 oxidation are unable to recover MCAs for subsequent analyses. We overcame this problem by employing SPME to directly capture the MCAs from the aqueous solution. We selected a SPME fiber with greater affinity for longer chain monoacids to compensate for the exponential decline of monoacid concentrations with increasing carbon numbers in meteorite IOM, allowing more accurate identification and quantification for the less abundant monoacids. We also determined the carbon and hydrogen isotopic ratios of individual MCAs derived from Murchinson IOM. Our results reveal significant similarity in both molecular structures and hydrogen isotopic ratios between the IOM aliphatic side chains and water-soluble MCAs in Murchison, suggesting that these compounds had common precursors. Our combined new approach of RuO 4 oxidation-SPME provides a new way to probe the molecular and isotopic characteristics of aliphatic side chains in carbonaceous chondrites.

Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

Science.gov (United States)

Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

2016-05-15

This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. Copyright © 2016 Elsevier B.V. All rights reserved.

Coal and biomass-based chemicals via carbonylation, hydroformylation and homologation reactions

Energy Technology Data Exchange (ETDEWEB)

Sunavala, P.D.; Raghunath, B.

The paper emphasizes the importance of carbonylation, hydroformylation and homologation reactions in the manufacture of organic chemicals (such as acetic acid, acetic anhydride, cellulose acetate, vinyl acetate monomer, aliphatic amines, isocyanates, methanol, ethanol, n-butanol, ethylene glycol, acrylic acid, etc.) from coal and biomass feedstocks. Topics covered are: synthesis of acetic acid; manufacture of acetic anhydride; synthesis of vinyl acetate monomer by carbonylation; synthesis of aliphatic amines by hydroformylation; synthesis of organic diisocyanates; ethanol synthesis by homologation of methanol; synthesis of ethylene glycol via hydroformylation of formaldehyde; synthesis of n- butanol and n-butyraldehyde by propylene formylation; synthesis of acrylic acid; homologation reaction of carboxylic acid esters with ruthenium catalysts; and synthesis of phenyl isocyanate from nitrobenzene by reductive carbonylation. 26 refs.

Cell Adhesion and Proliferation on Sulfonated and Non-Modified Chitosan Films.

Science.gov (United States)

Martínez-Campos, Enrique; Civantos, Ana; Redondo, Juan Alfonso; Guzmán, Rodrigo; Pérez-Perrino, Mónica; Gallardo, Alberto; Ramos, Viviana; Aranaz, Inmaculada

2017-05-01

Three types of chitosan-based films have been prepared and evaluated: a non-modified chitosan film bearing cationizable aliphatic amines and two films made of N-sulfopropyl chitosan derivatives bearing both aliphatic amines and negative sulfonate groups at different ratios. Cell adhesion and proliferation on chitosan films of C2C12 pre-myoblastic cells and B16 cells as tumoral model have been tested. A differential cell behavior has been observed on chitosan films due to their different surface modification. B16 cells have shown lower vinculin expression when cultured on sulfonated chitosan films. This study shows how the interaction among cells and material surface can be modulated by physicochemical characteristics of the biomaterial surface, altering tumoral cell adhesion and proliferation processes.

Effects of dietary amines on the gut and its vasculature.

Science.gov (United States)

Broadley, Kenneth J; Akhtar Anwar, M; Herbert, Amy A; Fehler, Martina; Jones, Elen M; Davies, Wyn E; Kidd, Emma J; Ford, William R

2009-06-01

Trace amines, including tyramine and beta-phenylethylamine (beta-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called 'friendly' bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and beta-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain.

Science.gov (United States)

Burchett, Scott A; Hicks, T Philip

2006-08-01

The trace amines are a structurally related group of amines and their isomers synthesized in mammalian brain and peripheral nervous tissues. They are closely associated metabolically with the dopamine, noradrenaline and serotonin neurotransmitter systems in mammalian brain. Like dopamine, noradrenaline and serotonin the trace amines have been implicated in a vast array of human disorders of affect and cognition. The trace amines are unique as they are present in trace concentrations, exhibit high rates of metabolism and are distributed heterogeneously in mammalian brain. While some are synthesized in their parent amine neurotransmitter systems, there is also evidence to suggest other trace amines may comprise their own independent neurotransmitter systems. A substantial body of evidence suggests that the trace amines may play very significant roles in the coordination of biogenic amine-based synaptic physiology. At high concentrations, they have well-characterized presynaptic "amphetamine-like" effects on catecholamine and indolamine release, reuptake and biosynthesis; at lower concentrations, they possess postsynaptic modulatory effects that potentiate the activity of other neurotransmitters, particularly dopamine and serotonin. The trace amines also possess electrophysiological effects that are in opposition to these neurotransmitters, indicating to some researchers the existence of receptors specific for the trace amines. While binding sites or receptors for a few of the trace amines have been advanced, the absence of cloned receptor protein has impeded significant development of their detailed mechanistic roles in the coordination of catecholamine and indolamine synaptic physiology. The recent discovery and characterization of a family of mammalian G protein-coupled receptors responsive to trace amines such as beta-phenylethylamine, tyramine, and octopamine, including socially ingested psychotropic drugs such as amphetamine, 3,4-methylenedioxymethamphetamine, N

Decomposition of some amines and amino acids in steam generator environments

International Nuclear Information System (INIS)

Jayaweera, P.; Hettiarachchi, S.; Millett, P.J.

1994-01-01

Hydrothermal decomposition rate constants and high temperature pH values of some selected high-molecular weight amines and amino acids were measured under simulated steam generator conditions. These amines and amino acids were evaluated as potential crevice buffering agents for steam generator applications in pressurized water reactors. The study showed that, although the high molecular weight amines undergo hydrothermal decomposition, they have a better buffer capacity than their low molecular weight counterparts at 290 C. The amines provide effective crevice buffering by increasing the pH of the simulated crevice solution by as much as 2.84 to 4.24 units. However, volatility data for the amines and amino acids are needed before in-plant testing to ensure that amines can concentrate sufficiently in steam generator crevices to provide effective buffering

Uranium diphosphonates templated by interlayer organic amines

International Nuclear Information System (INIS)

Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Albrecht-Schmitt, Thomas E.; Ewing, Rodney C.

2013-01-01

The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 °C results in the crystallization of a series of layered uranium diphosphonate compounds, [C 10 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Ubip2), [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} (UDAB), [C 2 H 10 N 2 ] 2 {(UO 2 ) 2 (H 2 O) 2 [CH 2 (PO 3 ) 2 ] 2 ·0.5H 2 O} (Uethyl), and [C 12 H 9 N 2 ]{UO 2 (H 2 O)[CH 2 (PO 3 )(PO 3 H)]} (Uphen). The crystal structures of the compounds are based on UO 7 units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C 6 H 14 N 2 ]{(UO 2 ) 2 [CH 2 (PO 3 )(PO 3 H)] 2 ·2H 2 O} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also shown. The structure is constructed from UO 7 pentagonal bipyramids (yellow), oxygen=red, phosphorus=magenta, carbon=black, and nitrogen=blue. Highlights: ► Organic amines act both as charge-balancing and as structure-directing agents. ► Extensive hydrogen bonding interactions with solvent water molecules and amines

Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

Science.gov (United States)

Googin, J.M.; Napier, J.M.; Travaglini, M.A.

1982-03-31

A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

Amine Functionalized Porous Network

KAUST Repository

Eddaoudi, Mohamed; Guillerm, Vincent; Weselinski, Lukasz Jan; Alkordi, Mohamed H.; Mohideen, Mohamed Infas Haja; Belmabkhout, Youssef

2015-01-01

Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

Amine Functionalized Porous Network

KAUST Repository

Eddaoudi, Mohamed

2015-05-28

Amine groups can be introduced in porous materials by a direct (one pot) or post-synthetic modification (PSM) process on aldehyde groups, and the resulting porous materials have increased gas affinity.

Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

Science.gov (United States)

Pratt, J. R.

1981-01-01

Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

Production of biogenic amines in "Salamini italiani alla cacciatora PDO".

Science.gov (United States)

Coı X0308 Sson, Jean Daniel; Cerutti, Caterina; Travaglia, Fabiano; Arlorio, Marco

2004-06-01

Various fermented and seasoned foods such as cheese, sauerkraut, wine, beer and meat products may contain biogenic amines. The aim of this paper was to describe the presence of some biogenic amines (histamine, tyramine, tryptamine, 2-phenylethylamine) in "Salamini italiani alla cacciatora PDO", a typical fermented-ripened dry sausage widely consumed in Italy. Total level of biogenic amines in commercial samples ranged from 71 to 586 mg kg(-1). The amine recovered in higher concentrations was tyramine (372 mg kg(-1)) followed by histamine (165 mg kg(-1)). The second aim of this work was the quality control of the production in order to determine the parameters influencing the presence of biogenic amines in ripened salami. Sausages sampled for analysis during production, manipulation and ripening showed the presence of tyramine (64.4 mg kg(-1)) only after 15 days of fermentation. All investigated biogenic amines were detected in "Salamini" after 21 days of fermentation. We suggest the control of biogenic as important tool to establish the better condition of preservation of "Salamini italiani alla cacciatore PDO" during their shelf-life.

Organic pollutants in the coastal environment off San Diego, California. 2: Petrogenic and biogenic sources of aliphatic hydrocarbons

International Nuclear Information System (INIS)

Tran, K.; Yu, C.C.; Zeng, E.Y.

1997-01-01

The results from the measurements of aliphatic hydrocarbons suggest that hydrocarbons suggest that hydrocarbons in the Point Loma Wastewater Treatment Plant (PLWTP) effluents are mainly petroleum derived; those in the Tijuana River runoff have largely originated from terrestrial plants with visible petroleum contamination; and those in the sea surface microlayer, sediment traps, and sediments at various coastal locations off San Diego have mostly resulted from biogenic contributions with enhanced microbial products in the summer season. Rainfall in the winter season appeared to amplify the inputs from terrestrial higher plants to the coastal areas. The PLWTP discharged approximately 3.85 metric tons of n-alkanes (C 10 -C 35 ) in 1994, well below the level (136 metric tons) estimated in 1979. The input of aliphatic hydrocarbons from the Tijuana River was about 0.101 metric tons in 1994. Diffusion, solubilization, evaporation, and microbial degradation seemed partially responsible for the difference in the concentrations and compositions of aliphatic hydrocarbons in different sample media, although the relative importance of each mechanism cannot be readily discerned from the available data. The results from analyses of aliphatic hydrocarbon compositional indices are generally consistent with those of polycyclic aromatic hydrocarbons

Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

Science.gov (United States)

Aleksandrova, Olga

2015-04-01

Among different classes of veterinary pharmaceuticals, Sulfadiazine (SDZ) is widely used in animal husbandry. Its residues were detected in different environmental compartments. However, soil is a hot spot for SDZ as it receives a large portion of excreted compounds through the application of manure during soil fertilization. Ample studies on the fate of SDZ in soils showed that a large portion forms nonextractable residues (NER) along with transformation products and a low mineralization (Mueller et al., 2013). A common observation was an initially fast formation of NER up to 10% of the applied amount promptly after the application of SDZ to soil, and this portion increased up to 50% within a few days (Mueller et al., 2013; Nowak et al., 2011). A common finding for SDZ, as for other sulfonamides, was biphasic kinetics of the formation of NER, which was attributed to the occurrence of two reaction processes: a rapid, often reversible process and a slower, irreversible process (Weber et al., 1996). A single-phase reaction process was also established under anaerobic treatment (Gulkowska et al., 2014). A major focus of this work is to elucidate a reaction mechanism of covalent binding of SDZ to soil that is currently required to estimate a risk of NER formed by SDZ in soils for human health. Taking into account a key role of the amine functional groups of SDZ on its reactivity in soil, nitroxide radicals with the sewed aromatic or aliphatic amines labeled soil samples and then, were investigated by means of ESR spectroscopy. 2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-yloxy and 4-amino-2,2,6,6-Tetramethylpiperidin-1-oxyl modeled decomposition products of SDZ with the aromatic and aliphatic amines, respectively. The application of the defined combination of both spin labels (SL) to different soils well simulated a change of a paramagnetic signal of soil organic radicals interacted with SDZ. After their application to soil, SL were found in soil sites characterized

Colorless triphenylamine-based aliphatic thermoset epoxy for multicolored and near-infrared electrochromic applications.

Science.gov (United States)

Chuang, Ya-Wen; Yen, Hung-Ju; Wu, Jia-Hao; Liou, Guey-Sheng

2014-03-12

In this study, two novel colorless thermoset epoxy resins with anodically electrochromism were prepared from the thermal curing of two triphenylamine-based diamine monomers, 4,4'-diamino-4″-methoxytriphenylamine (1) and N,N'-bis(4-aminophenyl)-N,N'-di(4-methoxylphenyl)-1,4-phenylenediamine (2) with aliphatic epoxy triglycidyl isocyanurate, respectively. The resulting thermoset epoxy resins showed excellent softening temperature (Ts, 270 and 280 °C) due to the rigid structure and highly crosslinking density. In addition, novel colorless epoxy resin films revealed good reversible electrochemical oxidation and interesting multi-electrochromic behavior with high contrast ratio both in visible and near-infrared regions. The aliphatic thermoset epoxy resins also exhibited high transparency in visible region as colorless and great potential for practical electrochromic applications.

New insights into controlling tube-bundle fouling using alternative amines

International Nuclear Information System (INIS)

Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Frattini, P.L.; Fruzzetti, K.

2002-01-01

A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. Atomic Energy of Canada Limited (AECL) and Electric Power Research Institute (EPRI) have been collaborating in an extensive investigation of the effectiveness of amines at controlling the rate of tube-bundle fouling under SG operating conditions. Tests have been performed using a radiotracing technique in a high-temperature fouling loop facility at Chalk River Laboratories operated by AECL. This investigation has provided new insights into the role played by the amine in determining the rate of tube-bundle fouling in the SG. These insights are being used by AECL and EPRI to develop criteria for the selection of an amine that has optimum properties for both corrosion control and deposit control in the secondary heat transport system. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

cobaloxime by aliphatic amine ligands · M Bhoopal N Ravi Kumar Reddy S Satyanarayana .... pp 129-134 Physical and Theoretical. Kinetics and mechanism of the oxidation of substituted benzylamines by cetyltrimethylammonium permanganate.

Production of Primary Amines by Reductive Amination of Biomass-Derived Aldehydes/Ketones.

Science.gov (United States)

Liang, Guanfeng; Wang, Aiqin; Li, Lin; Xu, Gang; Yan, Ning; Zhang, Tao

2017-03-06

Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO 2 , which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO 2 -containing multivalence Ru association species worked as a bifunctional catalyst, with RuO 2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extraction separation studies of uranium(VI) by amine oxides

International Nuclear Information System (INIS)

Ejaz, M.

1975-01-01

The extraction of uranium(VI) by two amine oxides, 4-(5-nonyl)pyridine oxide and trioctylamine oxide has been studied. The extraction behavior of these two N-oxides is compared. The dependence of extraction on the type of amine oxide and acid, nature of organic diluent, and amine oxide concentration has been investigated. The influence of the concentration of the metal and salting-out agents is described. The possible mechanism of extraction is discussed in the light of the results of extraction isotherms, loading radiodata, and log-log plots of amine oxide concentration vs distribution ratio. The separation factors for a number of metal ions are reported, and the separation of uranium from some fission elements has also been achieved

Effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch

International Nuclear Information System (INIS)

Silva, Leonardo G. Andrade e; Poveda, Patricia N.S.; Rezende, Maira L.; Rosa, Derval S.

2009-01-01

Biodegradable and green plastics have been studied in the last years. The aim of this paper is to study the effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch. The samples were irradiated at different doses 10 and 40 kGy in a linear accelerator. The biodegradability of the materials was evaluated by two methods: soil simulated and enzymatic. In the method enzymatic when it was used α-amylase, the irradiated samples presented faster biodegradation than the references non irradiated. The blend of aromatic aliphatic copolyester with corn starch (Ecobras R ) irradiated presented a bigger biodegradability than the aromatic aliphatic copolyester (Ecoflex R ) film in both methods studied. (author)

Metal-Mediated Couplings of Primary Alcohols with Amines and Carbohydrates

DEFF Research Database (Denmark)

Maggi, Agnese; Madsen, Robert

. The reaction is proposed to proceed by initial dehydrogenation of the alcohol to the aldehyde, which stays coordinated to the ruthenium centre. Then, nucleophilic attack of the amine affords the hemiaminal, which is released from ruthenium and converted into the imine. Project 2: Tin-mediated regioselective 6...... from alcohols and amines catalyzed by a ruthenium N-heterocyclic carbene complex. The successful method development and application of a convenient and direct (one step) synthesis of imines from alcohols and amines is described. The developed method provides quick andextended access to structurally...... and amines have been coupled in the presence of the catalyst to afford the corresponding imines in moderate to good yields. Optically pure amines gave the corresponding imines without any sign of racemization. Moreover, the one-pot diastereoselective addition of different organometallic reagents to the imine...

Chromosomal localization of the human vesicular amine transporter genes

Energy Technology Data Exchange (ETDEWEB)

Peter, D.; Finn, P.; Liu, Y.; Roghani, A.; Edwards, R.H.; Klisak, I.; Kojis, T.; Heinzmann, C.; Sparkes, R.S. (UCLA School of Medicine, Los Angeles, CA (United States))

1993-12-01

The physiologic and behavioral effects of pharmacologic agents that interfere with the transport of monoamine neurotransmitters into vesicles suggest that vesicular amine transport may contribute to human neuropsychiatric disease. To determine whether an alteration in the genes that encode vesicular amine transport contributes to the inherited component of these disorders, the authors have isolated a human cDNA for the brain transporter and localized the human vesciular amine transporter genes. The human brain synaptic vesicle amine transporter (SVAT) shows unexpected conservation with rat SVAT in the regions that diverge extensively between rat SVAT and the rat adrenal chromaffin granule amine transporter (CGAT). Using the cloned sequences with a panel of mouse-human hybrids and in situ hybridization for regional localization, the adrenal CGAT gene (or VAT1) maps to human chromosome 8p21.3 and the brain SVAT gene (or VAT2) maps to chromosome 10q25. Both of these sites occur very close to if not within previously described deletions that produce severe but viable phenotypes. 26 refs., 3 figs., 1 tab.

Gamma radiolysis of aliphatic sulfur compounds in aqueous solutions. A study to contribute to the analysis of the end products of the OH radical-induced oxidation of aliphatic mercaptanes, sulfides, and disulfides

International Nuclear Information System (INIS)

Weiss, J.

1982-01-01

By identifying and determining numerous hitherto unknown end products, the study in hand contributes to a better insight into the radiation chemical processes occurring in OH radical-induced oxidation of aliphatic sulfur compounds. An extraction method has been developed for the qualitative and quantitative analysis of end products in aqueous solution in order to determine these compounds down to the level of trace amounts. Separation of endproducts is achieved by means of gas chromatography and high-pressure liquid chromatography, subsequent identification by GC-MS analysis. Aliphatic mercaptanes are oxidized by OH radicals to thiyl radicals which after combination can be detected as disulfide. At high radiation doses, secondary reactions will lead to polysulfides of which the homologues could first be prepared as the pure substance. The end products of the γ-radiolysis of aliphatic thioethers are determined to be dithia compounds, symmetrical or asymmetrical disulfides, or polysulfides, depending on the thioethers. With some end products, the radiation chemical yield is found to be a function of the absorbed dose so that material balances are impossible. Intermediate thiyl, α-alkyl mercaptoalkyl or alkyl radicals can be captured by tetramethyl ethylene, cyclohexene or p-benzoquinone, and can then be identified as the relevant adducts. (orig./RB) [de

Characterization of particulate amines

International Nuclear Information System (INIS)

Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

1979-01-01

The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

Surfactants from petroleum paraffin wax

Energy Technology Data Exchange (ETDEWEB)

Kassem, T.M.; Hussein, M.H.; El Sayed, A.S.

Paraffin wax from Egyptian petroleum was purified and then oxidized to fatty acids which were esterified to form their methyl esters, fractionated and then hydrolysed. The obtained fatty acids were converted into the corresponding primary amines which were converted with ethylene oxide to form nonionic surfactants. The prepared primary amines were also converted into tertiary amines and then converted into cationic surfactants through condensation with benzyl chloride or 1-chloromethylnaphthalene. Also, amine oxide surfactants were prepared by oxidation of the tertiary amines with hydrogen peroxide. The surface active properties of all the prepared surfactants were determined, and the effect of their chemical structure on the surfactant properties are discussed in this paper.

N-nitroso compounds in the air environment

International Nuclear Information System (INIS)

Fine, D.H.; Edwards, G.S.; Krull, I.S.; Wolf, M.H.

1979-01-01

The measurement and chemistry of N-nitroso compounds, most of which are known carcinogens, in the air are discussed. Methods for the analysis of N-nitroso compounds in the ambient air usually employ a nitrosamine-specific detector, coupled to a gas chromatograph or a high-pressure liquid chromatograph, with structural confirmation by high-resolution mass spectroscopy and extensive artifact experiments required. Airborne N-nitrosamines have been detected at significant trace levels near leather tanneries, rocket fuel plants, tire factories, tobacco smoke, amine factories, cooking vapors and in the ambient air. Nitrosation of amines has been demonstrated with nitrogen oxides, certain C-nitro compounds and nitrous acid, and tertiary amines, tertiary amine oxides and primary amines have been nitrosated

Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part I. Regeneration of Amine-Carboxylic Acid Extracts

Energy Technology Data Exchange (ETDEWEB)

Poole, Loree Joanne [Univ. of California, Berkeley, CA (United States); King, C. Judson [Univ. of California, Berkeley, CA (United States)

1990-03-01

Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO₂ and H₂S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, succinic acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The

Amine-selective bioconjugation using arene diazonium salts.

Science.gov (United States)

Diethelm, Stefan; Schafroth, Michael A; Carreira, Erick M

2014-08-01

A novel bioconjugation strategy is presented that relies on the coupling of diazonium terephthalates with amines in proteins. The diazonium captures the amine while the vicinal ester locks it through cyclization, ensuring no reversibility. The reaction is highly efficient and proceeds under mild conditions and short reaction times. Densely functionalized, complex natural products were directly coupled to proteins using low concentrations of coupling partners.

STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

Institute of Scientific and Technical Information of China (English)

QIU Kunyuan; ZHANG Jingyi; FENG Xinde(S. T. Voong)

1983-01-01

Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET＞DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET＞DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp=K [DMT]1/2 [MEMA]3/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.

Base metal dehydrogenation of amine-boranes

Science.gov (United States)

Blacquiere, Johanna Marie [Ottawa, CA; Keaton, Richard Jeffrey [Pearland, TX; Baker, Ralph Thomas [Los Alamos, NM

2009-06-09

A method of dehydrogenating an amine-borane having the formula R.sup.1H.sub.2N--BH.sub.2R.sup.2 using base metal catalyst. The method generates hydrogen and produces at least one of a [R.sup.1HN--BHR.sup.2].sub.m oligomer and a [R.sup.1N--BR.sup.2].sub.n oligomer. The method of dehydrogenating amine-boranes may be used to generate H.sub.2 for portable power sources, such as, but not limited to, fuel cells.

Systems of cerium(3) nitrate-dimethyl amine nitrate-water and cerium(3) nitrate-dimethyl amine nitrate-water

International Nuclear Information System (INIS)

Mininkov, N.E.; Zhuravlev, E.F.

1976-01-01

Solubility of solid phases in the systems cerium(3)nitrate-water-dimethyl amine nitrate and cerium(3)nitrate-water-dimethyl amine nitrate has been st ed by the method of isothermal sections at 25 and 50 deo. C. It has been shown that one anhydrous compound is formed in each system with a ratio of cerium(3) nitrate to amine nitrate 1:5. The compounds formed in the systems have been separated from the corresponding solutions and studied by microcrystalloscopic, X-ray phase, thermal and infrared spectroscopic methods. On the basis of spectroscopic studies the following formula has been assigned to the compound: [(CH 3 ) 2 NH 2 + ] 5 x[Ce(NO 3 ) 8 ]. The thermal analysis of the compound has shown that its melting point is 106 deg C. The solubility isotherms in the system Ce(NO 3 ) 3 -H 2 O-(C 2 H 5 ) 2 NHxHNO 3 consist of three branches which intersect in two eutonic points

40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acid amine condensate... Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid salts. (a... a fatty acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject to reporting...

Development and application of bacterial cultures for the removal of chlorinated aliphatics

NARCIS (Netherlands)

Janssen, Dick B.; de Koning, Wim

1995-01-01

The possibility of obtaining microbial cultures for the degradation of halogenated aliphatic hydrocarbons is mainly determined by the diversity and activity of catabolic enzymes that exist in nature. If a suitable organism is available, applications for the treatment of different waste streams can

Critical properties of some aliphatic symmetrical ethers

International Nuclear Information System (INIS)

Nikitin, Eugene D.; Popov, Alexander P.; Bogatishcheva, Nataliya S.

2014-01-01

Highlights: • Critical properties of simple aliphatic ethers were measured. • The ethers decompose at near-critical temperatures. • Pulse-heating method with short residence times was used. -- Abstract: The critical temperatures T c and the critical pressures p c of dihexyl, dioctyl, and didecyl ethers have been measured. According to the measurements, the coordinates of the critical points are T c = (665 ± 7) K, p c = (1.44 ± 0.04) MPa for dihexyl ether, T c = (723 ± 7) K, p c = (1.19 ± 0.04) MPa for dioctyl ether, and T c = (768 ± 8) K, p c = (1.03 ± 0.03) MPa for didecyl ether. All the ethers studied degrade chemically at near-critical temperatures. A pulse-heating method applicable to measuring the critical properties of thermally unstable compounds has been used. The times from the beginning of a heating pulse to the moment of reaching the critical temperature were from 0.06 to 0.46 ms. The short residence times provide little decomposition of the substances in the course of the experiments. The critical properties of the ethers investigated in this work have been discussed together with those of methyl to butyl ethers. The experimental critical constants of the ethers have been compared with those estimated by the group-contribution methods of Wilson and Jasperson and Marrero and Gani. The Wilson/Jasperson method provides a better estimation of the critical temperatures and pressures of simple aliphatic ethers in comparison with the Marrero/Gani method if reliable normal boiling temperatures are used in the method of Wilson and Jasperson

Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids.

Science.gov (United States)

Fu, Ming-Chen; Shang, Rui; Cheng, Wan-Min; Fu, Yao

2015-07-27

A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient one-pot synthesis of indol-3-yl-glycines via uncatalyzed Friedel-Crafts reaction in water.

Science.gov (United States)

Ghandi, Mehdi; Taheri, Abuzar

2009-03-05

The three component reaction of primary aliphatic amines, glyoxalic acid and indole or N-methylindole in water at ambient temperature affords indol-3-yl or N-methylindol-3-yl-glycine in almost quantitative yields.

Effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch

Energy Technology Data Exchange (ETDEWEB)

Silva, Leonardo G. Andrade e; Poveda, Patricia N.S., E-mail: lgasilva@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rezende, Maira L.; Rosa, Derval S. [Universidade Sao Francisco, Itatiba, SP (Brazil)

2009-07-01

Biodegradable and green plastics have been studied in the last years. The aim of this paper is to study the effect of electron beam irradiation on the biodegradability of aromatic aliphatic copolyester film and their blend with corn starch. The samples were irradiated at different doses 10 and 40 kGy in a linear accelerator. The biodegradability of the materials was evaluated by two methods: soil simulated and enzymatic. In the method enzymatic when it was used alpha-amylase, the irradiated samples presented faster biodegradation than the references non irradiated. The blend of aromatic aliphatic copolyester with corn starch (Ecobras{sup R}) irradiated presented a bigger biodegradability than the aromatic aliphatic copolyester (Ecoflex{sup R}) film in both methods studied. (author)

Detection of cometary amines in samples returned by Stardust

Science.gov (United States)

Glavin, D. P.; Dworkin, J. P.; Sandford, S. A.

2008-02-01

The abundances of amino acids and amines, as well as their enantiomeric compositions, were measured in samples of Stardust comet-exposed aerogel and foil using liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC-FD/ToF-MS). A suite of amino acids and amines including glycine, L-alanine, β-alanine (BALA), γ-amino-n-butyric acid (GABA), ɛ-amino-n-caproic acid (EACA), ethanolamine (MEA), methylamine (MA), and ethylamine (EA) were identified in acid-hydrolyzed, hot-water extracts of these Stardust materials above background levels. With the exception of MA and EA, all other primary amines detected in cometexposed aerogel fragments C2054,4 and C2086,1 were also present in the flight aerogel witness tile that was not exposed to the comet, indicating that most amines are terrestrial in origin. The enhanced relative abundances of MA and EA in comet-exposed aerogel compared to controls, coupled with MA to EA ratios (C2054,4: 1.0 ± 0.2; C2086,1: 1.8 ± 0.2) that are distinct from preflight aerogels (E243-13C and E243-13F: 7 ± 3), suggest that these volatile amines were captured from comet Wild 2. MA and EA were present predominantly in an acid-hydrolyzable bound form in the aerogel, rather than as free primary amines, which is consistent with laboratory analyses of cometary ice analog materials. It is possible that Wild 2 MA and EA were formed on energetically processed icy grains containing ammonia and approximately equal abundances of methane and ethane. The presence of cometary amines in Stardust material supports the hypothesis that comets were an important source of prebiotic organic carbon and nitrogen on the early Earth.

Catalyst for hydrogen-amine D exchange

International Nuclear Information System (INIS)

Holtslander, W.J.; Johnson, R.E.

1976-01-01

A process is claimed for deuterium isotopic enrichment (suitable for use in heavy water production) by amine-hydrogen exchange in which the exchange catalyst comprises a mixture of alkyl amides of two metals selected from the group consisting of the alkali metals. Catalyst mixtures comprising at least one of the alkali amides of lithium and potassium are preferred. At least one of the following benefits are obtained: decreased hydride formation, decreased thermal decomposition of alkyl amide, increased catalyst solubility in the amine phase, and increased exchange efficiency. 11 claims

Influence of amine structure on the post-cured photo-yellowing of novel amine diacrylate terminated ultraviolet and electron beam cured coatings

International Nuclear Information System (INIS)

Allen, N.S.; Lo, D.

1990-01-01

The post ultraviolet (UV) and electron beam (EB) cured photo-yellowing of nine novel amine terminated diacrylate monomers has been compared with that of standard commercial diethylamine diacrylate monomer using second order derivative UV absorption spectroscopy. Whilst all the UV cured monomers exhibited an initial rapid growth in UV absorption followed by a rapid photo-bleaching, the EB cured monomers exhibited a very slow growth in absorption followed by a plateau and subsequent slow photo-bleaching. In the former case the residual benzophenone photo-initiator is sensitising the photo-yellowing reaction and its subsequent photo-bleaching. Differences in the rates may be determined by the nature of the exciplex between the terminal amine groups and the benzophenone initiator. With regard to the nature of the amine structure all the simple alkylamines exhibit the greatest degree of photo-yellowing whilst hydroxyl containing amines are generally lower. In the former case methylene hydrogen atoms alpha to the nitrogen atom are important for abstraction. Dicyclohexylamine provides the most stable monomer toward photo-yellowing due to the stability of the alpha methylene hydrogen atoms and steric hindrance by the two bulky cyclohexane rings towards the formation of conjugated chromophores. For the EB cured monomers the degree of photo-yellowing increases with increasing alkyl chain length of the amine group due to the increased possibility of the formation of conjugated chromophores. (author)

Structure and activity of Aspergillus nidulans copper amine oxidase

DEFF Research Database (Denmark)

McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

2011-01-01

Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

SEDIMENT-ASSOCIATED REACTIONS OF AROMATIC AMINES. 2. QSAR DEVELOPMENT

Science.gov (United States)

The fate of aromatic amines in soils and sediments is dominated by irreversible binding through nucleophilic addition and oxidative radical coupling. Despite the common occurrence of the aromatic amine functional group in organic chemicals, the molecular properties useful for pr...

Contribution to the study of the mechanism of extraction of uranyl chloride by long chain aliphatic amines; Contribution a l'etude du mecanisme d'extraction du chlorure d'uranyle par les amines aliphatiques a longues chaines

Energy Technology Data Exchange (ETDEWEB)

Rubinstein, G R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-06-01

After having studied and developed the mechanisms which may 'a priori' explain the extraction process (co-ordination, ion association or intermediate mechanism), experience shows that ion association only should be taken into consideration. The structure of the organic complex of uranyl chloride has been defined on the basis of the study of the variation of the distribution coefficient of uranium between the two phases at the equilibrium as a function of successively the activity of Cl{sup -} ions in the aqueous phase, the concentration of amine salt in the organic phase and finally of the concentration of uranium in the aqueous phase. The plotting of the results in bi-logarithmic co-ordinates enables us to propose the following formula for the extracted compound: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. The calculation of the equilibrium constant of formation of the organic compound of uranyl chloride has been possible in the case of diluted solutions of uranium only. (author) [French] Apres avoir expose et developpe les mecanismes qui a priori pouvaient expliquer le processus d'extraction (coordination, association d'ions ou mecanisme intermediaire), le recours a l'experience a finalement permis de ne retenir que l'association d'ions. La structure du complexe organique de chlorure d'uranyle a ete definie a partir de l'etude de la variation du coefficient de partage de l'uranium entre les deux phases a l'equilibre en fonction successivement de l'activite des ions Cl{sup -} en phase aqueuse, de la concentration de sel d'amine en phase organique et enfin de la concentration d'uranium de la phase aqueuse. La representation bilogarithmique des resultats de ces essais a permis de proposer la formule suivante pour le compose extrait: UO{sub 2}Cl{sub 4}{sup --}(NR{sub 3}H{sup +}){sub 2}. Le calcul de la constante d'equilibre de formation du compose organique de chlorure d'uranyle a ete seulement possible pour les solutions diluees en uranium. (auteur)

Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources : Enzymatic Synthesis, Characterization, and Properties

NARCIS (Netherlands)

Jiang, Yi; Alberda van Ekenstein, Gerhard; Woortman, Albert J. J.; Loos, Katja

2014-01-01

Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)-catalyzed polycondensations of succinate, itaconate, and 1,4-butanediol. The effects of monomer substrates and polymerization methods on enzymatic

Influence of molecular weight on the fracture properties of aliphatic polyketone terpolymers

NARCIS (Netherlands)

Zuiderduin, W.C.J.; Homminga, D.S.; Homminga, D.S.; Huetink, Han; Gaymans, R.J.

2003-01-01

The influence of polymer molecular weight on the mechanical properties of aliphatic polyketones was investigated. The molecular weight varied from 100,000 to 300,000 g mol21. The crystallinity was found to be independent of polymer molecular weight, as was the glass transition temperature. The yield

Dicationic and zwitterionic catalysts for the amine-initiated, immortal ring-opening polymerisation of rac-lactide: facile synthesis of amine-terminated, highly heterotactic PLA

NARCIS (Netherlands)

Clark, L.; Cushion, M.G.; Dyer, H.E.; Schwarz, A.D.; Duchateau, R.; Mountford, P.

2010-01-01

Dicationic, zwitterionic and conventional yttrium compounds act as catalysts for the primary or secondary amine-initiated immortal ROP of rac-lactide; amine-terminated, highly heterotactic poly(rac-lactides) with narrow polydispersities and well-controlled molecular weights are prepared in this

Non-hazardous organic solvents in the paraffin-embedding technique: a rational approach. Aliphatic monoesters for clearing and dewaxing: butyldecanoate

DEFF Research Database (Denmark)

Lyon, H; Holm, I; Prentø, P

1995-01-01

The aim of this study was to substitute hazardous compounds, used in tissue processing and dewaxing, with compounds having lowest possible toxicity and inflammability without impairing the morphology, staining characteristics, or diagnostic value of the tissue sections. All aromatic compounds...... and aliphatic hydrocarbons (e.g. alkanes, isoparaffins, petroleum distillates, etc.) were rejected, primarily due to their high vapour pressure. Based on a theoretical study of compounds used for clearing, a number of non-hazardous potential substitutes were chosen. The following experimental study narrowed...... the group to three unbranched, saturated, aliphatic monoesters containing 12-14 carbon atoms. On large-scale testing of these compounds, we found butyldecanoate to be the closest to an ideal substitute for aromatic and aliphatic hydrocarbons in the histology department: the section quality is at least equal...

Thermal properties of wood reacted with a phosphorus pentoxide–amine system

Science.gov (United States)

Hong-Lin Lee; George C. Chen; Roger M. Rowell

2004-01-01

The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

Extraction and separation of molybdenum and vanadium from acidic and alkaline media using tertiary and quaternary amines

International Nuclear Information System (INIS)

Stas, J.; Dahdouh, A.; Rizkallah, I.

2010-01-01

The extraction of vanadium and molybdenum from alkaline leaching solutions coming from the leaching of fly ash of fired electrical power stations by tri-n dodecylamine (TDA) and metyl trioctyl ammonium chloride (QA) in the presence of octanol-2 as modifier in kerosene has been investigated. Some parameters influencing the extraction process have been studied (agitation time, octanol-2 percentage in the organic phase, pH of the aqueous phase, concentration of TDA and QA, concentration of vanadium in the aqueous phase and temperature). It has been shown that the extraction capacity of both V and Mo by TDA increases by decreasing the pH of the aqueous phase and reaches a maximum extraction at pH=2. The concentration of TDA plays an important role on the separation selectivity between these two elements, where the selectivity of Mo vs V (S M o, v=[Mo] o rg/[V] o rg) increases with the decrease of TDA concentration to reach a maximum selectivity value of S M o, v = 0.37 for [TDA]=1.5 M. It has been also shown that, whatever vanadium concentration in the aqueous phase, molybdenum will be first extracted, then the remaining free TDA will be occupied by vanadium. Concerning the quaternary amine QA, the pH value of the aqueous phase plays an important role in the separation process between vanadium and molybdenum, where the value of the selectivity of V vs Mo (S v , Mo=[V] o rg/[Mo] o rg) is maximal for pH>8 and the pH=8.5 is the best value which permit a good separation between these two elements at QA concentration equal to 6%, especially at high vanadium concentration. It is very important to note that for low vanadium concentration and at pH=1.5 the value of the selectivity of Mo vs V (S M o,v) increases with increasing Mo concentration in the aqueous phase which enable us the separation between these two elements under these experimental conditions, where Mo will be much more extracted than vanadium. The stripping of vanadium and molybdenum from the loaded organic

Bioinspired organocatalytic aerobic C-H oxidation of amines with an ortho-quinone catalyst.

Science.gov (United States)

Qin, Yan; Zhang, Long; Lv, Jian; Luo, Sanzhong; Cheng, Jin-Pei

2015-03-20

A simple bioinspired ortho-quinone catalyst for the aerobic oxidative dehydrogenation of amines to imines is reported. Without any metal cocatalysts, the identified optimal ortho-quinone catalyst enables the oxidations of α-branched primary amines and cyclic secondary amines. Mechanistic studies have disclosed the origins of different performances of ortho-quinone vs para-quinone in biomimetic amine oxidations.

Impact of thiol and amine functionalization on photoluminescence properties of ZnO films

International Nuclear Information System (INIS)

Jayalakshmi, G.; Saravanan, K.; Balasubramanian, T.

2013-01-01

In the present study, we have investigated surface functionalization of ZnO films with dodecanethiol (Thiol) and trioctylamine (amine) by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle (CA) and photoluminescence (PL) measurements. The chemical bondings of thiol and amine with ZnO have been confirmed via the formation of Zn–S and Zn–N bonds by XPS measurements. AFM measurements on ZnO films before and after surface functionalization with thiol and amine provide evidence for the successful functionalization of thiol and amine on ZnO surfaces without any island formation. The CA measurements on ZnO films before and after surface functionalization with thiol and amine show the hydrophobic nature. PL measurements of thiol and amine functionalized ZnO show enhancements of UV emission and quenching of visible emission. The enhanced UV emissions in thiol and amine functionalized ZnO films suggest that the surface defects such as oxygen vacancies are passivated by thiol and amine functionalization. -- Highlights: ► Surface functionalization is a new approach to reduce surface dependent non-radiative process. ► Oxygen vacancies are passivated on surface functionalization. ► Thiol and amine functionalized ZnO show enhancements of UV emission

Intolerance to dietary biogenic amines: a review.

Science.gov (United States)

Jansen, Sophia C; van Dusseldorp, Marijke; Bottema, Kathelijne C; Dubois, Anthony E J

2003-09-01

To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and adverse. Additionally, the keywords histamine, tyramine, and phenylethylamine were combined with headache, migraine, urticaria, oral challenge, and oral provocation. Articles were also selected from references in relevant literature. Only oral challenge studies in susceptible patients were considered. Studies with positive results (ie, studies in which an effect was reported) were only eligible when a randomized, double-blind, placebo-controlled design was used. Eligible positive result studies were further evaluated according to a number of scientific criteria. Studies with negative results (ie, studies in which no effect was reported) were examined for factors in their design or methods that could be responsible for a false-negative outcome. Results of methodologically weak or flawed studies were considered inconclusive. A total of 13 oral challenge studies (5 with positive results and 8 with negative results) were found. Three of them (all with positive results) were considered ineligible. By further evaluation of the 10 eligible studies, 6 were considered inconclusive. The 4 conclusive studies all reported negative results. One conclusive study showed no relation between biogenic amines in red wine and wine intolerance. Two conclusive studies found no effect of tyramine on migraine. One conclusive study demonstrated no relation between the amount of phenylethylamine in chocolate and headache attacks in individuals with headache. The current scientific literature shows no relation between the oral ingestion of biogenic amines and food intolerance reactions. There is therefore no scientific basis for dietary recommendations concerning biogenic amines in such patients.

Tunable properties of novel tetra-functional fluorene-based benzoxazines from mixed amines: Synthesis, characterization and curing kinetics

International Nuclear Information System (INIS)

Feng, Tiantian; Wang, Jun; Pan, Lan; Derradji, Mehdi; Ramdani, Noureddine; Liu, Wenbin; Zhou, Haoran

2016-01-01

Highlights: • Synthesis of tetra-functional fluorene-based benzoxazines with tunable properties. • Cure reaction could be successfully described with the autocatalytic model. • The benzoxazines show an excellent heat resistance with T_g of 291–307 °C. • The benzoxazines exhibit good thermal stability with T_5 over 340 °C. - Abstract: A series of tetra-functional fluorene-based benzoxazines containing both flexible linear aliphatic chain and rigid aromatic structure in their backbones were synthesized using mixed amines such as aniline and n-octylamine, 2,7-dihydroxy-9,9-bis-(4-hydroxyphenyl)fluorene (THPF) and paraformaldehyde as raw materials via Mannich reaction. The prepared benzoxazine monomers were identified by fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance ("1H NMR). In addition, the curing behavior, curing kinetics and rheological properties of these monomers as well as the thermal and mechanical properties of their cured resins were studied using a rheometer, differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), and dynamic thermomechanical analyzer (DMA). The newly developed benzoxazines show good processibility, excellent thermal stability and high glass transition temperature (T_g) values ranging from 291 to 307 °C. By varying the proportion of n-octylamine to aniline, the properties of these resins are tuned.

PcMtr, an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum

NARCIS (Netherlands)

Trip, H; Evers, ME; Driessen, AJM

2004-01-01

The gene encoding an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum was cloned, functionally expressed and characterized in Saccharomyces cerevisiae M4276. The permease, designated PcMtr, is structurally and functionally homologous to Mtr of Neurospora crassa, and

Efficient One-Pot Synthesis of Indol-3-yl-Glycines via Uncatalyzed Friedel-Crafts Reaction in Water

Directory of Open Access Journals (Sweden)

Mehdi Ghandi

2009-03-01

Full Text Available The three component reaction of primary aliphatic amines, glyoxalic acid and indole or N-methylindole in water at ambient temperature affords indol-3-yl or N-methylindol-3-yl-glycine in almost quantitative yields.

Composition of amino acids and bioactive amines in common wines of Brazil

Directory of Open Access Journals (Sweden)

Bruna Carla Agustini

2014-10-01

Full Text Available Since most consumed wines in Brazil are common wines and since their representativeness is not accounted for in scientific research, current study quantifies bioactive amines and their precursors in Brazilian sweet and dry common wines, correlates the formation of amines with physical and chemical parameters and clusters studied areas by their amine and amino acid contents. Forty-seven wine samples varying in type, color and origin were analyzed simultaneously for seventeen amino acids, ammonium ion and five bioactive amines by reversed-phase high performance liquid chromatography and ultraviolet detection after the derivation phase. Physical and chemical analyses comprised titratable acidity, pH, organic acids, sugar and alcohol contents. Sweet wines had lower concentrations of amino acids and bioactive amines. Dry white wines had higher amino acid contents when compared to those in dry red wines. Since multivariate data analysis confirmed similarities between the studied regions, their unity as potential viniculture area was reinforced. Amine levels in Brazilian common wines were reported for the first time and results reinforced the importance of bioactive amines quantification and the use of suitable vinification practices to reduce their formation.

Conditions allowing the formation of biogenic amines in cheese

NARCIS (Netherlands)

Joosten, H.M.L.J.

1988-01-01

A study was undertaken to reveal the conditions that allow the formation of biogenic amines in cheese.

The starters most commonly used in the Dutch cheese industry do not have decarboxylative properties. Only if the milk or curd is contaminated with non-starter bacteria, amine

Blue Chitin columns for the extraction of heterocyclic amines from urine samples

DEFF Research Database (Denmark)

Bang, J.; Frandsen, Henrik Lauritz; Skog, K.

2004-01-01

During normal cooking of meat, a class of mutagenic/carcinogenic compounds called heterocyclic amines is formed. Heterocyclic amines are rapidly absorbed and metabolised in the human body, and for estimation of the intake of heterocyclic amines, it is useful to determinate their levels in the uri...

Analysis of Biogenic Amines by GC/FID and GC/MS

OpenAIRE

Nakovich, Laura

2003-01-01

Low levels of biogenic amines occur naturally, but high levels (FDA sets 50 ppm of histamine in fish as the maximum allowable level) can lead to scombroid poisoning. Amines in general are difficult to analyze by Gas Chromatography (GC) due to their lack of volatility and their interaction with the GC column, often leading to significant tailing and poor reproducibility. Biogenic amines need to be derivatized before both GC and HPLC analyses. The objective of this research was to devel...

Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

Science.gov (United States)

Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

2018-05-01

Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

Electrochemical degradation of aromatic amines on BDD electrodes

International Nuclear Information System (INIS)

Pacheco, M.J.; Santos, V.; Ciriaco, L.; Lopes, A.

2011-01-01

The electrochemical oxidation of four aromatic amines, with different substituent groups, 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid (A1), 5-amino-2-methoxybenzenesulfonic acid (A2), 2,4-dihydroxyaniline hydrochloride (A3) and benzene-1,4-diamine (A4), was performed using as anode a boron-doped diamond electrode, commercially available at Adamant Technologies. Tests were run at room temperature with model solutions of the different amines, with concentrations of 200 ppm, using as electrolyte 0.035 M Na 2 SO 4 aqueous solutions, in a batch cell with recirculation, at different current densities (200 and 300 A m -2 ). The following analyses were performed with the samples collected during the assays: UV-Vis spectrophotometry, chemical oxygen demand (COD), total organic carbon (TOC), total Kjeldahl nitrogen, ammonia nitrogen, nitrates and HPLC. Results have shown a good electrodegradation of all the amines tested, with COD removals, after 6 h assays, higher than 90% and TOC removals between 60 and 80%. Combustion efficiency (η C ), which measures the tendency to convert organic carbon to CO 2 , was also determined for all the amines, being η CA1 CA2 CA3 CA4 = 0.99.

Control of Biogenic Amines in Fermented Sausages: Role of Starter Cultures

Science.gov (United States)

Latorre-Moratalla, M.L.; Bover-Cid, Sara; Veciana-Nogués, M.T.; Vidal-Carou, M.C.

2012-01-01

Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed. PMID:22586423

Control of biogenic amines in fermented sausages: role of starter cultures

Directory of Open Access Journals (Sweden)

Mariluz eLatorre-Moratalla

2012-05-01

Full Text Available Biogenic amines show biological activity and exert undesirable physiological effects when absorbed at high concentrations. Biogenic amines are mainly formed by microbial decarboxylation of amino acids and thus are usually present in a wide range of foods, fermented sausages being one of the major biogenic amine sources. The use of selected starter cultures is one of the best technological measures to control aminogenesis during meat fermentation. Although with variable effectiveness, several works show the ability of some starters to render biogenic amine-free sausages. In this paper, the effect of different starter culture is reviewed and the factors determining their performance discussed.

Secondary and tertiary hyperparathyroidism.

Science.gov (United States)

Jamal, Sophie A; Miller, Paul D

2013-01-01

We reviewed the etiology and management of secondary and tertiary hyperparathyroidism. Secondary hyperparathyroidism is characterized by an increase in parathyroid hormone (PTH) that is appropriate and in response to a stimulus, most commonly low serum calcium. In secondary hyperparathyroidism, the serum calcium is normal and the PTH level is elevated. Tertiary hyperparathyroidism is characterized by excessive secretion of PTH after longstanding secondary hyperparathyroidism, in which hypercalcemia has ensued. Tertiary hyperparathyroidism typically occurs in men and women with chronic kidney disease usually after kidney transplant. The etiology and treatment of secondary hyperparathyroidism is relatively straightforward whereas data on the management of tertiary hyperparathyroidism is limited to a few small trials with short follow-up. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Aromatic-aliphatic copolyesters based on waste poly(ethylene terephthalate) and their biodegradability

Czech Academy of Sciences Publication Activity Database

Prokopová, I.; Vlčková, E.; Šašek, Václav; Náhlík, J.; Soukupová-Chaloupková, V.; Skolil, J.

-, 052 (2008), s. 1-9 ISSN 1618-7229 R&D Projects: GA ČR GA203/03/0508; GA ČR GA203/06/0528 Institutional research plan: CEZ:AV0Z50200510 Keywords : aromatic-aliphatic colpolyesters * rhodococcus erythropolis * biodegradability Subject RIV: EE - Microbiology, Virology Impact factor: 0.661, year: 2008

Amine oxidases as important agents of pathological processes of rhabdomyolysis in rats.

Science.gov (United States)

Gudkova, O O; Latyshko, N V; Shandrenko, S G

2016-01-01

In this study we have tested an idea on the important role of amine oxidases (semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase) as an additional source of oxidative/carbonyl stress under glycerol-induced rhabdomyolysis, since the enhanced formation of reactive oxygen species and reactive carbonyl species in a variety of tissues is linked to various diseases. In our experiments we used the sensitive fluorescent method devised for estimation of amine oxidases activity in the rat kidney and thymus as targeted organs under rhabdomyolysis. We have found in vivo the multiple rises in activity of semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase (2-4.5 times) in the corresponding cell fractions, whole cells or their lysates at the 3-6th day after glycerol injection. Aberrant antioxidant activities depended on rhabdomyolysis stage and had organ specificity. Additional treatment of animals with metal chelator ‘Unithiol’ adjusted only the activity of antioxidant enzymes but not amine oxidases in both organs. Furthermore the in vitro experiment showed that Fenton reaction (hydrogen peroxide in the presence of iron) products alone had no effect on semicarbazide-sensitive amine oxidase activity in rat liver cell fraction whereas supplementation with methylglyoxal resulted in its significant 2.5-fold enhancement. Combined action of the both agents had additive effect on semicarbazide-sensitive amine oxidase activity. We can assume that biogenic amine and polyamine catabolism by amine oxidases is upregulated by oxidative and carbonyl stress factors directly under rhabdomyolysis progression, and the increase in catabolic products concentration contributes to tissue damage in glycerol-induced acute renal failure and apoptosis stimulation in thymus.

Conformational dynamics of semiflexibly bridged electron donor-acceptor systems comprising long aliphatic tails

NARCIS (Netherlands)

Bleisteiner, B.; Marian, T.; Schneider, S.; Brouwer, A.M.; Verhoeven, J.W.

2001-01-01

In continuation of our previous work on the conformational dynamics (harpooning mechanism) of semiflexibly bridged electron donor-acceptor systems we have studied a derivative with two long aliphatic chains tethered to the donor and acceptor moieties, respectively. The fitting of the time- and

Using of mass spectrum for prognosis of melting temperature of monatomic aliphatic spirits

International Nuclear Information System (INIS)

Vazhev, V. V.

2004-01-01

In present article researching possibility of prediction of melting temperature (MT) of monatomic aliphatic spirits with using mass-spectra as descriptors structure of molecules. Mass-spectra of 84 aliphatic spirits were used. Mass-spectra were preliminarily transformed on special formula before calculations for receiving work dates of descriptors. Calculations fulfilled with help of the computer program PROGROC. Quality of prediction characterized by coefficient of R-correlation between predicted and experimental dates MT and standard s-deviation. Coefficient of R-correlation between experimental and calculated dates account for 0.9785, standard s-deviation = 11.25 deg. C. Singly R and S for training and control excerpt equally 0.9789 and 11.31 deg. C, 0,9789 and 8.87 deg. C accordingly. Advantage of workable by us method lie in that, what on comparable with literature data of accuracy for prediction property is enough to have only mass-spectrum of substance

Characterization of cure kinetics and physical properties of a high performance, glass fiber-reinforced epoxy prepreg and a novel fluorine-modified, amine-cured commercial epoxy

Science.gov (United States)

Bilyeu, Bryan

Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4'-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC) and by high speed DSC when the reaction rate is high. The changes in physical properties indicating increasing conversion are followed by shifts in glass transition temperature determined by DSC, temperature-modulated DSC (TMDSC), step scan DSC and high speed DSC, thermomechanical (TMA) and dynamic mechanical (DMA) analysis and thermally stimulated depolarization (TSD). Changes in viscosity, also indicative of degree of conversion, are monitored by DMA. Thermal stability as a function of degree of cure is monitored by thermogravimetric analysis (TGA). The parameters of the general kinetic equations, including activation energy and rate constant, are explained and used to compare results of various techniques. The utilities of the kinetic descriptions are demonstrated in the construction of a useful time-temperature-transformation (TTT) diagram and a continuous heating transformation (CHT) diagram for rapid determination of processing parameters in the processing of prepregs. Shrinkage due to both resin consolidation and fiber rearrangement is measured as the linear expansion of the piston on a quartz dilatometry cell using TMA. The shrinkage of prepregs was determined to depend on the curing temperature, pressure applied and the fiber orientation. Chemical modification of an epoxy was done by mixing a fluorinated aromatic amine (aniline) with a standard aliphatic amine as a curing agent for a commercial Diglycidylether of Bisphenol-A (DGEBA) epoxy. The resulting cured network

Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

Science.gov (United States)

Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

2016-06-01

We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination

KAUST Repository

Moulin, Solenne; Dentel, Hé lè ne; Pagnoux-Ozherelyeva, Anastassiya; Gaillard, Sylvain; Poater, Albert; Cavallo, Luigi; Lohier, Jean Franç ois; Renaud, Jean Luc

2013-01-01

. Festival of amination: Two series of modified Knölker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight

Hydrogen-transfer and charge-transfer in photochemical and radiation induced reactions. Progress report, November 1, 1975--October 31, 1976

International Nuclear Information System (INIS)

Cohen, S.G.

1976-10-01

The relative importance of light absorption, quenching of triplet, and hydrogen transfer repair has been examined in retardation by mercaptans of photoreduction of aromatic ketones by alcohols. In the reduction of benzophenone by 2-propanol, retardation is efficient and, after correction for the first two effects, is due entirely to hydrogen-transfer repair, as indicated by deuterium labeling. In reduction of acetophenone by α-methylbenzyl alcohol, repair by hydrogen transfer is also operative. In reduction of benzophenone by benzhydrol, retardation is less efficient and is due to quenching, as the ketyl radical does not abstract hydrogen from mercaptan rapidly in competition with coupling. Deuterium isotope effects are discussed in terms of competitive reactions. Photoreduction of benzophenone by 2-butylamine and by triethylamine is retarded by aromatic mercaptans and disulfides. Of the retardation not due to light absorption and triplet quenching by the sulfur compounds, half is due to hydrogen-transfer repair, as indicated by racemization and deuterium labeling. The remainder is attributed to quenching by the sulfur compound of the charge-transfer-complex intermediate. Photoreduction by primary and secondary amines, but not by tertiary amines, is accelerated by aliphatic mercaptans. The acceleration is attributed to catalysis of hydrogen transfer by the mercaptan in the charge-transfer complex. The effect is large in hydrocarbon solvent, less in polar organic solvents and absent in water

Clustering of amines and hydrazines in atmospheric nucleation

Science.gov (United States)

Li, Siyang; Qu, Kun; Zhao, Hailiang; Ding, Lei; Du, Lin

2016-06-01

It has been proved that the presence of amines in the atmosphere can enhance aerosol formation. Hydrazine (HD) and its substituted derivatives, monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH), which are organic derivatives of amine and ammonia, are common trace atmospheric species that may contribute to the growth of nucleation clusters. The structures of the hydrazine and amine clusters containing one or two common nucleation molecules (ammonia, water, methanol and sulfuric acid) have been optimized using density functional theory (DFT) methods. The clusters growth mechanism has been explored from the thermochemistry by calculating the Gibbs free energies of adding an ammonia, water, methanol or sulfuric acid molecule step by step at room temperature, respectively. The results show that hydrazine and its derivatives could enhance heteromolecular homogeneous nucleation in the earth's atmosphere.

A multi-purpose tool for food inspection: Simultaneous determination of various classes of preservatives and biogenic amines in meat and fish products by LC-MS.

Science.gov (United States)

Molognoni, Luciano; Daguer, Heitor; de Sá Ploêncio, Leandro Antunes; De Dea Lindner, Juliano

2018-02-01

This paper describes an innovative fast and multipurpose method for the chemical inspection of meat and fish products by liquid chromatography-tandem mass spectrometry. Solid-liquid extraction and low temperature partitioning were applied to 17 analytes, which included large bacteriocins (3.5kDa) and small molecules (organic acids, heterocyclic compounds, polyene macrolides, alkyl esters of the p-hydroxybenzoic acid, aromatic, and aliphatic biogenic amines and polyamines). Chromatographic separation was achieved in 10min, using stationary phase of di-isopropyl-3-aminopropyl silane bound to hydroxylated silica. Method validation was in accordance to Commission Decision 657/2002/CE. Linear ranges were among 1.25-10.0mgkg -1 (natamycin and parabens), 2.50-10.0mgkg -1 (sorbate and nisin), 25.0-200mgkg -1 (biogenic amines, hexamethylenetetramine, benzoic and lactic acids), and 50.0-400mgkg -1 (citric acid). Expanded measurement uncertainty (U) was estimated by single laboratory validation combined to modeling in two calculation approaches: internal (U = 5%) and external standardization (U = 24%). Method applicability was checked on 89 real samples among raw, cooked, dry fermented and cured products, yielding acceptable recoveries. Many regulatory issues were revealed, corroborating the need for enhancement of the current analytical methods. This simple execution method dispenses the use of additional procedures of extraction and, therefore, reduces costs over time. It is suitable for routine analysis as a screening or confirmatory tool for both qualitative and quantitative results, replacing many time consuming analytical procedures. Copyright © 2017 Elsevier B.V. All rights reserved.

Uranium diphosphonates templated by interlayer organic amines

Energy Technology Data Exchange (ETDEWEB)

Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, 52428 Juelich (Germany); Institut fuer Kristallographie, RWTH Aachen University, D-52066 Aachen (Germany); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556 (United States); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States)

2013-02-15

The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 Degree-Sign C results in the crystallization of a series of layered uranium diphosphonate compounds, [C{sub 10}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Ubip2), [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} (UDAB), [C{sub 2}H{sub 10}N{sub 2}]{sub 2}{l_brace}(UO{sub 2}){sub 2}(H{sub 2}O){sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sub 2}{center_dot}0.5H{sub 2}O{r_brace} (Uethyl), and [C{sub 12}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Uphen). The crystal structures of the compounds are based on UO{sub 7} units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also

Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

OpenAIRE

Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

1990-01-01

Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride),...

Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

Science.gov (United States)

Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

2011-01-01

Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers.

Science.gov (United States)

Sokolenko, Taras M; Dronkina, Maya I; Magnier, Emmanuel; Yagupolskii, Lev M; Yagupolskii, Yurii L

2017-05-14

The "chlorination/fluorination" technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

Factors influencing the regioselectivity of the oxidation of asymmetric secondary amines with singlet oxygen.

Science.gov (United States)

Ushakov, Dmitry B; Plutschack, Matthew B; Gilmore, Kerry; Seeberger, Peter H

2015-04-20

Aerobic amine oxidation is an attractive and elegant process for the α functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet-oxygen-mediated oxidation of 1° and 2° amines is sensitive to the strength of the α-C-H bond and steric factors. Estimation of the relative bond dissociation energy by natural bond order analysis or by means of one-bond C-H coupling constants allowed the regioselectivity of secondary amine oxidations to be explained and predicted. In addition, the findings were utilized to synthesize highly regioselective substrates and perform selective amine cross-couplings to produce imines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

78 FR 17656 - Certain New Chemicals; Receipt and Status Information

Science.gov (United States)

2013-03-22

... Corporation (G) Roof membrane (G) Amine adduct. hardener. P-13-0240 1/25/2013 4/24/2013 Carboline (G) Coating.... P-13-0244 1/30/2013 4/29/2013 CBI (S) Polymeric binder (G) Aliphatic for coatings. polyurethane. P...

Analysis of amines by pH-Metrie in organic media

International Nuclear Information System (INIS)

Hamidi, A.; Elias, Abdelhamid; Achache, M.; Didi, M.

1999-01-01

Amines with long hydro carbonic strength and principally Trioclkylamines, are characterised by an important complexation mechanism for certain metals. This is the case for trioctylamine (TOA) which is very used in purification and uranium recovery from certain ores (1,2). This substance is generally found mixed with mono and di-octyl amines in commercial products and in synthesis mixtures. The purpose of this work is to develop a pH titration method in an organic media for a mixture consisted of mono, di and tri octyl amines (MOA, DOA et TOA). Adequate operating analysis condition have been proposed, based on intrinsic chemical properties for each precipitated substances (3,4). The obtained results show that this technique is recommended for qualitative and quantitative analysis of precipitated amines mixtures. The method is reproducible and the detection limit can reach 0,0001 molar

Early Post-Irradiation Changes in the Metabolism of Biogenic Amines; Les Changements Precoces du Metabolisme des Amines Biogenes apres Irradiation

Energy Technology Data Exchange (ETDEWEB)

Deanovic, Z [Institut Rudjer Boskovic, Zagreb, Yugoslavia (Croatia)

1971-03-15

There is accumulating evidence for the radiation-induced release of biogenic amines from their body stores. Having in mind the high patho-physiological activity of these ''local'' hormones and ''neuro-hormones'', it is reasonable to assume that they play an important role in the pathogenesis of the acute radiation syndrome. Under these pathological conditions the possible synergic and antagonistic effects of biogenic amines due to their complex interactions must be taken into consideration. The extent and dose-dependence of post-irradiation changes in the metabolism of histamine, serotonin, catecholamines and acetylcholine will be examined regarding particularly the search for biochemical indicators of radiation injury. The determination of bio-amines and their metabolites in urine seems to be a suitable method for following up those metabolic changes which could be of a biodosimetrical and/or prognostical value. Data published on this subject, obtained in experimental animals as well as in man, have been reviewed and the applicability of these tests is discussed. (author) [French] Des preuves se sont accumulees, qui demontrent que les amines biogenes sont liberees de leurs depots sous l'effet des rayonnements ionisants. Etant donne la grande activite pathophysiologique de ces hormones 'locales' et 'neurohormones', il est raisonnable de considerer que ces substances biogenes jouent un role important dans la pathogenese du syndrome aigu d'irradiation. Dans ces conditions pathologiques il faut tenir compte des effets synergiques et antagonistes des bio-amines, lies a des interactions compliquees. Les changements metaboliques en fonction de la dose recue font l'objet d'un examen qui englobe les alterations quantitatives de .'histamine, de la serotonine, des catecholamines et de l'acetylcholine et dont l'objectif est la recherche sur des indicateurs biochimiques de la lesion provoquee par l'irradiation. L'analyse des bio-amines et de leurs metabolites dans les urines

Extraction of uranyl sulfate with primary amine

International Nuclear Information System (INIS)

Mrnka, M.; Bizek, V.; Nekovar, P.; Cizevska, S.; Schroetterova, D.

1984-01-01

PRIMENE JM-T was used for extraction. Its composition was found to approach the general formula C 21 H 43 NH 2 . It was found that the extraction of uranyl sulfate is lower in case of a higher steady-state concentration of sulfuric acid in the aqueous phase. Extraction is accompanied with coextraction of water. The results obtained showed that uranyl sulfate passes into the organic phase by two mechanisms: extraction with amine sulfate and extraction with free amine. A mathematical description of the process was made based on the obtained results. (E.S.)

In vitro lipofection with novel series of symmetric 1,3-dialkoylamidopropane-based cationic surfactants containing single primary and tertiary amine polar head groups.

Science.gov (United States)

Sheikh, Mohammad; Feig, Jennifer; Gee, Becky; Li, Song; Savva, Michalakis

2003-06-01

A novel series of symmetric double-chained primary and tertiary 1,3-dialkoylamido monovalent cationic lipids were synthesized and evaluated for their transfection activities. In the absence of the helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), only the primary and tertiary dioleoyl derivatives 1,3lmp5 and 1,3lmt5, respectively elicited transfection activity. This is a striking difference between symmetrical 1,2-diacyl glycerol-based monovalent cationic lipids that always found both dioleoyl and dimyristoyl analogues being efficient transfection reagents. In the presence of helper lipid, all cationic derivatives induced marker gene expression, except the dilauroyl analogues 1,3lmp1 and 1,3lmt1 that elicited no transfection activity. Combining electrophoretic mobility data of the lipoplexes at different charge ratios with transfection activity suggested two requirements for high transfection activity with monovalent double-chained cationic lipids, that is, binding/association of the lipid to the plasmid DNA and membrane fusion properties of the lipid layers surrounding the DNA.

Catalytic enantioselective addition of organometallic reagents to N-formylimines using monodentate phosphoramidite ligands

NARCIS (Netherlands)

Pizzuti, Maria Gabriella; Minnaard, Adriaan J.; Feringa, Ben L.

2008-01-01

[GRAPHICS] The asymmetric synthesis of protected amines via the copper/phosphoramidite-catalyzed addition of organozine and organoaluminum reagents to N-acylimines, generated in situ from aromatic and aliphatic alpha-amidosulfones, is reported. High yields of optically active N-formyl-protected

OCCUPATIONAL ASTHMA CAUSED BY A HARDENER CONTAINING AN ALIPHATIC AND A CYCLOALIPHATIC DIAMINE

NARCIS (Netherlands)

ALEVA, RM; AALBERS, R; KOETER, GH; DEMONCHY, JGR

An otherwise healthy 44-yr-old man experienced a serious attack of bronchial obstruction after working with resins and hardeners, releasing fumes of a mixture of an aliphatic and a cycloaliphatic diamine hardener. Eight hours after deliberate challenge with the hardener a large increase of airway

Poly(Amido Amine)s containing agmatine and butanol side chains as efficient gene carriers

NARCIS (Netherlands)

Won, Young-Wook; Ankone, Martinus J.K.; Engbersen, Johannes F.J.; Feijen, Jan; Kim, S.W.

2016-01-01

A new type of bioreducible poly(amido amine) copolymer is synthesized by the Michael addition polymerization of cystamine bisacrylamide (CBA) with 4-aminobutylguanidine (agmatine, AGM) and 4-aminobutanol (ABOL). Since the positively charged guanidinium groups of AGM and the hydroxybutyl groups of

Multi-Objective Optimization for Solid Amine CO2 Removal Assembly in Manned Spacecraft

Directory of Open Access Journals (Sweden)

Rong A

2017-07-01

Full Text Available Carbon Dioxide Removal Assembly (CDRA is one of the most important systems in the Environmental Control and Life Support System (ECLSS for a manned spacecraft. With the development of adsorbent and CDRA technology, solid amine is increasingly paid attention due to its obvious advantages. However, a manned spacecraft is launched far from the Earth, and its resources and energy are restricted seriously. These limitations increase the design difficulty of solid amine CDRA. The purpose of this paper is to seek optimal design parameters for the solid amine CDRA. Based on a preliminary structure of solid amine CDRA, its heat and mass transfer models are built to reflect some features of the special solid amine adsorbent, Polyethylenepolyamine adsorbent. A multi-objective optimization for the design of solid amine CDRA is discussed further in this paper. In this study, the cabin CO2 concentration, system power consumption and entropy production are chosen as the optimization objectives. The optimization variables consist of adsorption cycle time, solid amine loading mass, adsorption bed length, power consumption and system entropy production. The Improved Non-dominated Sorting Genetic Algorithm (NSGA-II is used to solve this multi-objective optimization and to obtain optimal solution set. A design example of solid amine CDRA in a manned space station is used to show the optimal procedure. The optimal combinations of design parameters can be located on the Pareto Optimal Front (POF. Finally, Design 971 is selected as the best combination of design parameters. The optimal results indicate that the multi-objective optimization plays a significant role in the design of solid amine CDRA. The final optimal design parameters for the solid amine CDRA can guarantee the cabin CO2 concentration within the specified range, and also satisfy the requirements of lightweight and minimum energy consumption.

Effect of foamability index of short chain alkyl amines on flotation of quartz

Directory of Open Access Journals (Sweden)

Szczerkowska Sabina

2016-01-01

Full Text Available Amines can be used for flotation of various minerals, especially quartz. The flotation efficiency of quartz depends on the amine type and dose. It was proved that the shorter alkyl amine, higher amine concentration has to be used to recover quartz at the same level. In flotation amines play a role of both collectors and frothers. The ability of a amine to collect particles can be expressed in the form of contact angle, while the foaming properties by different parameters including dynamic foamability index (DFI and critical coalescence concentration (CCC. Determination of DFI and CCC requires advanced techniques and methods. Therefore, in this paper a rapid and facile method for determination of foaming properties of amines and also other surfactants was used. It was based on measuring the initial foam and froth heights in a conventional flotation machine at different concentrations of surfactants. The foam height-concentration curve was described by utilizing an empirical equation which was based on one-adjustable parameter called the foamability index (FI. In this work the foamability index was determined for butylamine (ButNH2, hexylamine (HexNH2 and octylamine (OctNH2 as examples of short chain alkyl amines. The determined foamability indices were 92, 12 and 4 mg/dm3 for ButNH2, HexNH2 and OctNH2, respectively. It was shown that when the flotation results of quartz were presented in the form of recovery versus normalized amine concentration in relation to the foamability index (c/FI, all the experimental data points converged to one curve. It indicates that amines act similarly but at different concentrations expressed as FI. The foamability index seems to be a useful parameter for characterizing any flotation frother.

Facile and Green Synthesis of Saturated Cyclic Amines

Directory of Open Access Journals (Sweden)

Arruje Hameed

2017-10-01

Full Text Available Single-nitrogen containing saturated cyclic amines are an important part of both natural and synthetic bioactive compounds. A number of methodologies have been developed for the synthesis of aziridines, azetidines, pyrrolidines, piperidines, azepanes and azocanes. This review highlights some facile and green synthetic routes for the synthesis of unsubstituted, multisubstituted and highly functionalized saturated cyclic amines including one-pot, microwave assisted, metal-free, solvent-free and in aqueous media.

Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

Science.gov (United States)

Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

2018-02-14

The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

Amine terminated SAMs: Investigating why oxygen is present in these films

International Nuclear Information System (INIS)

Baio, J.E.; Weidner, T.; Brison, J.; Graham, D.J.; Gamble, Lara J.; Castner, David G.

2009-01-01

Self-assembled monolayers (SAMs) on gold prepared from amine-terminated alkanethiols have long been employed as model positively charged surfaces. Yet in previous studies significant amounts of unexpected oxygen containing species are always detected in amine terminated SAMs. Thus, the goal of this investigation was to determine the source of these oxygen species and minimize their presence in the SAM. The surface composition, structure, and order of amine-terminated SAMs on Au were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectroscopy (ToF-SIMS), sum frequency generation (SFG) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. XPS determined compositions of amine-terminated SAMs in the current study exhibited oxygen concentrations of 2.4 ± 0.4 atomic %, a substantially lower amount of oxygen than reported in previously published studies. High-resolution XPS results from the S 2p , C 1s and N 1s regions did not detect any oxidized species. Angle-resolved XPS indicated that the small amount of oxygen detected was located at or near the amine head group. Small amounts of oxidized nitrogen, carbon and sulfur secondary ions, as well as ions attributed to water, were detected in the ToF-SIMS data due to the higher sensitivity of ToF-SIMS. The lack of N-O, S-O, and C-O stretches in the SFG spectra are consistent with the XPS and ToF-SIMS results and together show that oxidation of the amine-terminated thiols alone can only account for, at most, a small fraction of the oxygen detected by XPS. Both the SFG and angle-dependent NEXAFS indicated the presence of gauche defects in the amine SAMs. However, the SFG spectral features near 2865 cm -1 , assigned to the stretch of the methylene group next to the terminal amine unit, demonstrate the SAM is reasonably ordered. The SFG results also show another broad feature near 3200 cm -1 related to hydrogen-bonded water. From this multi-technique investigation it is

Acid extraction by supported liquid membranes containing basic carriers

International Nuclear Information System (INIS)

Danesi, P.R.; Cianetti, C.; Horwitz, E.P.

1983-01-01

The extraction of HNO 3 (nitric acid) from aqueous solutions by permeation through a number of supported liquid membranes containing basic carriers dissolved in diethylbenzene has been studied. The results have shown that the best permeations are obtained with long chain aliphatic amines (TLA, Primene JM-T) followed by TOPO (trioctylphosphine oxide) and then by other monofunctional and bifunctional organophosphorous basic carriers. The influence of an aliphatic diluent on the permeability of HNO 3 through a supported liquid membrane containing TLA as carrier was also investigated. In this case the permeability to HNO 3 decreases as a result of the lower diffusion coefficient of the acid-carrier complex in the more vicous aliphatic solvent. 4 figures

Biogenic Amines in Insect Antennae

Directory of Open Access Journals (Sweden)

Marianna I. Zhukovskaya

2017-06-01

Full Text Available Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA and its metabolic precursor tyramine (TA affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA modulates gustatory neurons. Serotonin can serve as a neurotransmitter in some afferent mechanosensory neurons and both as a neurotransmitter and neurohormone in efferent fibers targeted at the antennal vessel and mechanosensory organs. As a neurohormone, serotonin affects the generation of the transepithelial potential by sensillar accessory cells. Other possible targets of biogenic amines in insect antennae are hygro- and thermosensory neurons and epithelial cells. We suggest that the insect antenna is partially autonomous in the sense that biologically active substances entering its hemolymph may exert their effects and be cleared from this compartment without affecting other body parts.

Evaluation of Efficient and Practical Methods for the Preparation of Functionalized Aliphatic Trifluoromethyl Ethers

Directory of Open Access Journals (Sweden)

Taras M. Sokolenko

2017-05-01

Full Text Available The “chlorination/fluorination” technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

Copper(II)-catalyzed electrophilic amination of quinoline N-oxides with O-benzoyl hydroxylamines.

Science.gov (United States)

Li, Gang; Jia, Chunqi; Sun, Kai; Lv, Yunhe; Zhao, Feng; Zhou, Kexiao; Wu, Hankui

2015-03-21

Copper acetate-catalyzed C-H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields. Electrophilic amination can also be performed in good yield on a gram scale.

Oxidative Degradation of Aminosilica Adsorbents Relevant to Postcombustion CO 2 Capture

KAUST Repository

Bollini, Praveen

2011-05-19

Coal-fired power plant flue gas exhaust typically contains 3-10% oxygen. While it is known that the monoethanolamine (MEA) oxidative degradation rate is a critical parameter affecting liquid amine absorption processes, the effect of oxygen on the stability of solid amine adsorbents remains unexplored. Here, oxidative degradation of aminosilica materials is studied under accelerated oxidizing conditions to assess the stability of different supported amine structures to oxidizing conditions. Adsorbents constructed using four different silane coupling agents are evaluated, three with a single primary, secondary, or tertiary amine at the end of a propyl surface linker, with the fourth having one secondary propylamine separated from a primary amine by an ethyl linker. Under the experimental conditions used in this study, it was found that both amine type and proximity had a significant effect on oxidative degradation rates. In particular, the supported primary and tertiary amines proved to be stable to the oxidizing conditions used, whereas the secondary amines degraded at elevated treatment temperatures. Because secondary amines are important components of many supported amine adsorbents, it is suggested that the oxidative stability of such species needs to be carefully considered in assessments of postcombustion CO2 capture processes based on supported amines. © 2011 American Chemical Society.

Oxidative Degradation of Aminosilica Adsorbents Relevant to Postcombustion CO 2 Capture

KAUST Repository

Bollini, Praveen; Choi, Sunho; Drese, Jeffrey H.; Jones, Christopher W.

2011-01-01

Coal-fired power plant flue gas exhaust typically contains 3-10% oxygen. While it is known that the monoethanolamine (MEA) oxidative degradation rate is a critical parameter affecting liquid amine absorption processes, the effect of oxygen on the stability of solid amine adsorbents remains unexplored. Here, oxidative degradation of aminosilica materials is studied under accelerated oxidizing conditions to assess the stability of different supported amine structures to oxidizing conditions. Adsorbents constructed using four different silane coupling agents are evaluated, three with a single primary, secondary, or tertiary amine at the end of a propyl surface linker, with the fourth having one secondary propylamine separated from a primary amine by an ethyl linker. Under the experimental conditions used in this study, it was found that both amine type and proximity had a significant effect on oxidative degradation rates. In particular, the supported primary and tertiary amines proved to be stable to the oxidizing conditions used, whereas the secondary amines degraded at elevated treatment temperatures. Because secondary amines are important components of many supported amine adsorbents, it is suggested that the oxidative stability of such species needs to be carefully considered in assessments of postcombustion CO2 capture processes based on supported amines. © 2011 American Chemical Society.

Synthesis and Characterization of Ethylene DiamineTetera Acetic Acid Polyester-amides polymer with Aminoalcohol

Directory of Open Access Journals (Sweden)

Dakhil Nasser Taha

2017-02-01

Full Text Available linear aromatic and aliphatic polyester-amides (PEAs have been synthesized by polycondensation of aliphatic and aromatic aminoalcohol (Ethanol amine, 2-amino-2-methyl-propan-1-ol, m-amino phenol with Ethylenediaminetetraacetic acid (EDTA as a favorable and combined complexing compound was joined into the polymer backbone with poly addition reactions. These polymers were characterized by FTIR, 1H NMR, solubility studies , elemental analysis, , Thermal analyses such as TGA were measured, intrinsic viscosity. The poly(ester-amides obtained show good thermal stability.

Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

Science.gov (United States)

Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

2009-01-01

The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

Enzymatic network for production of ether amines from alcohols

DEFF Research Database (Denmark)

Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

2016-01-01

We constructed an enzymatic network composed of three different enzymes for the synthesis of valuable ether amines. The enzymatic reactions are interconnected to catalyze the oxidation and subsequent transamination of the substrate and to provide cofactor recycling. This allows production...... of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

Ultrafast relaxation dynamics of amine-substituted bipyridyl ruthenium(II) complexes

Science.gov (United States)

Song, Hongwei; Wang, Xian; Yang, WenWen; He, Guiying; Kuang, Zhuoran; Li, Yang; Xia, Andong; Zhong, Yu-Wu; Kong, Fan'ao

2017-09-01

The excited state properties of a series of ruthenium(II) amine-substituted bipyridyl complexes, [Ru(bpy)n(NNbpy)3-n]2+, were investigated by steady-state and transient absorption spectroscopy, as well as quantum chemical calculations. The steady-state absorption spectra of these complexes in CH3CN show a distinct red-shift of the 1MLCT absorption with increasing numbers of amine substituent, whereas the emission spectra indicate an energy gap order of [Ru(bpy)3]2+ > [Ru(bpy)2(NNbpy)]2+ > [Ru(NNbpy)3]2+ > [Ru(bpy)(NNbpy)2]2+. Nanosecond, femtosecond transient absorption and electrochemical measurements suggest that NNbpy ligand has a strong influence on the electronic and emission properties of these complexes, due to electron-rich amine substituent. We illustrate how the numbers of amine substituent modulate the spectroscopic properties of transition metal complexes, which is related to the design of new electro-active systems with novel photoelectrochemical properties.

Nano ZnO/amine composites antimicrobial additives to acrylic paints

Directory of Open Access Journals (Sweden)

H.B. Kamal

2015-12-01

Full Text Available Nano ZnO has been widely used as an antimicrobial agent not only for food packaging purposes but also in many coating processes. The present work is meant to enhance such functions through the preparation of sustainable and safe conduct of nano ZnO composites with amine derivatives that are characterized by their antimicrobial and anti-fouling functional activities. The results obtained revealed a more comprehensive approach to the antimicrobial function based on the reported active oxide species role. The oxide/amine composites and the acrylic emulsion paint were characterized chemically and structurally through FT-IR, TGA and TEM supported by biological assessment of each ZnO/amine composite action. Results of the study concluded that equilibrium between the nano ZnO particles size, their dispersion form, and amine ability to stabilize the actively produced oxygen species responsible for the antimicrobial function, should all be accounted for when persistence of antimicrobial agent efficiency is regarded.

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

Energy Technology Data Exchange (ETDEWEB)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk [Kyung Hee Univ., Seoul (Korea, Republic of)

2012-11-15

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O{sub 2} might be the main reason for the activity of the selenium catalyst for this reaction.

Alkylselenite-catalyzed Oxidative Carbonylation of Amines: Density Functional Theory Study

International Nuclear Information System (INIS)

Hwang, Sun; Kim, Hoon Sik; Cheong, Minserk

2012-01-01

Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O 2 might be the main reason for the activity of the selenium catalyst for this reaction

From caffeine to fish waste: amine compounds present in food and drugs and their interactions with primary amine oxidase.

LENUS (Irish Health Repository)

Olivieri, Aldo

2011-07-01

Tissue bound primary amine oxidase (PrAO) and its circulating plasma-soluble form are involved, through their catalytic activity, in important cellular roles, including the adhesion of lymphocytes to endothelial cells during various inflammatory conditions, the regulation of cell growth and maturation, extracellular matrix deposition and maturation and glucose transport. PrAO catalyses the oxidative deamination of several xenobiotics and has been linked to vascular toxicity, due to the generation of cytotoxic aldehydes. In this study, a series of amines and aldehydes contained in food and drugs were tested via a high-throughput assay as potential substrates or inhibitors of bovine plasma PrAO. Although none of the compounds analyzed were found to be substrates for the enzyme, a series of molecules, including caffeine, the antidiabetics phenformin and tolbutamide and the antimicrobial pentamidine, were identified as PrAO inhibitors. Although the inhibition observed was in the millimolar and micromolar range, these data show that further work will be necessary to elucidate whether the interaction of ingested biogenic or xenobiotic amines with PrAO might adversely affect its biological roles.

Metal Monolithic Amine-grafted Zeolite for CO{sub 2} Capture

Energy Technology Data Exchange (ETDEWEB)

Chuang, Steven

2011-03-31

The solid amine sorbent for CO{sub 2} capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO{sub 2} capture capacity or low stability. The solid amine sorbent developed in this project exhibited more than 3.2 mmol/g and degraded less than 10% even after 500 cycles of heating and cooling in absence of steam. The presence of steam further enhanced CO{sub 2} capture capacity. The cost of the sorbent is estimated to be less than $7.00/lb. This sorbent was developed using the results of in situ infrared spectroscopic study. Infrared results showed that CO{sub 2} adsorbs on TEPA (tetraethylenepentamine)/PEG (polyethylene glycol) as carbamates and bicarbonates. The CO{sub 2} adsorption capacity and oxidation resistance of the amine sorbent can be enhanced by the interactions between NH{sub 2} of TEPA molecules with the OH group of PEG molecules. PEG was also found to be effectively disperse and immobilize the aromatic amines for SO{sub 2} adsorption. The infrared study also showed that SiO{sub 2} is a significantly better support than zeolites due to its proper hydrophobicity. The results of this study led to the development of a high performance solid amine sorbent under simulated gas flow condition in a fixed bed, a fluidized bed, and a metal monolith unit. This study showed heat transfer could become a major technical issue in scaling up a fixed bed adsorber. The use of the fluidized bed and metal monoliths can alleviate the heat transfer issue. The metal monolith could be suitable for small scale applications due to the high cost of manufacturing; the fluidized bed mode would be most suitable for large scale applications. Preliminary economic analysis suggested that the Akron solid amine process would cost 45% less than that of MEA process.

Purification and characterization of the amine dehydrogenase from a facultative methylotroph.

Science.gov (United States)

Coleman, J P; Perry, J J

1984-01-01

Strain RA-6 is a pink-pigmented organism which can grow on a variety of substrates including methylamine. It can utilize methylamine as sole source of carbon via an isocitrate lyase negative serine pathway. Methylamine grown cells contain an inducible primary amine dehydrogenase [primary amine: (acceptor) oxidoreductase (deaminating)] which is not present in succinate grown cells. The amine dehydrogenase was purified to over 90% homogeneity. It is an acidic protein (isoelectric point of 5.37) with a molecular weight of 118,000 containing subunits with approximate molecular weights of 16,500 and 46,000. It is active on an array of primary terminal amines and is strongly inhibited by carbonyl reagents. Cytochrome c or artificial electron acceptors are required for activity; neither NAD nor NADP can serve as primary electron acceptor.

T V Thanikai Velan

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. T V Thanikai Velan. Articles written in Bulletin of Materials Science. Volume 23 Issue 5 October 2000 pp 425-429 Polymers. Aliphatic amine cured PDMS–epoxy interpenetrating network system for high performance engineering applications—Development and characterization.

I Mohammed Bilal

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. I Mohammed Bilal. Articles written in Bulletin of Materials Science. Volume 23 Issue 5 October 2000 pp 425-429 Polymers. Aliphatic amine cured PDMS–epoxy interpenetrating network system for high performance engineering applications—Development and characterization.

In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

Directory of Open Access Journals (Sweden)

Ayber Yıldrım

2014-01-01

Full Text Available In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2 functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets.

Degradation of halogenated aliphatic compounds by the ammonia- oxidizing bacterium Nitrosomonas europaea.

Science.gov (United States)

Vannelli, T; Logan, M; Arciero, D M; Hooper, A B

1990-01-01

Suspensions of Nitrosomonas europaea catalyzed the ammonia-stimulated aerobic transformation of the halogenated aliphatic compounds dichloromethane, dibromomethane, trichloromethane (chloroform), bromoethane, 1,2-dibromoethane (ethylene dibromide), 1,1,2-trichloroethane, 1,1,1-trichloroethane, monochloroethylene (vinyl chloride), gem-dichloroethylene, cis- and trans-dichloroethylene, cis-dibromoethylene, trichloroethylene, and 1,2,3-trichloropropane, Tetrachloromethane (carbon tetrachloride), tetrachloroethylene (perchloroethylene), and trans-dibromoethylene were not degraded. PMID:2339874

High-resolution gas chromatographic analysis of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons

International Nuclear Information System (INIS)

Perez, M.; Gonzalez, D.

1988-01-01

A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs

New procedure of selected biogenic amines determination in wine samples by HPLC

Energy Technology Data Exchange (ETDEWEB)

Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

2014-06-27

Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

Amine functionalized nanodiamond promotes cellular adhesion, proliferation and neurite outgrowth

International Nuclear Information System (INIS)

Hopper, A P; Dugan, J M; Gill, A A; Haycock, J W; Claeyssens, F; Fox, O J L; May, P W

2014-01-01

In this study, we report the production of amine functionalized nanodiamond. The amine functionalized nanodiamond forms a conformal monolayer on a negatively charged surface produced via plasma polymerization of acrylic acid. Nanodiamond terminated surfaces were studied as substrates for neuronal cell culture. NG108-15 neuroblastoma-glyoma hybrid cells were successfully cultured upon amine functionalized nanodiamond coated surfaces for between 1 and 7 d. Additionally, primary dorsal root ganglion (DRG) neurons and Schwann cells isolated from Wistar rats were also successfully cultured over a period of 21 d illustrating the potential of the coating for applications in the treatment of peripheral nerve injury. (paper)

Amine oxidase from lentil seedlings: energetic domains and effect of temperature on activity.

Science.gov (United States)

Moosavi-Nejad, S Z; Rezaei-Tavirani, M; Padiglia, A; Floris, G; Moosavi-Movahedi, A A

2001-07-01

Copper/TPQ amine oxidases from mammalian and plant sources have shown many differences in substrate specificity and molecular properties. In this work the activity of lentil seedling amine oxidase was followed at various temperatures in 100 mM potassium phosphate buffer, pH 7, using benzylamine as substrate. The discontinuous Arrhenius plot of lentil amine oxidase showed two distinct phases with a jump between them. Thermal denaturation of the enzyme, using differential scanning calorimetry under the same experimental conditions, showed a transition at the same temperature ranges in the absence of substrate, indicating the occurrence of conformational changes, with an enthalpy change of about 175.9 kJ/mole. The temperature-induced changes of the activity of lentil amine oxidase are compared with those of bovine serum amine oxidase (taken from the literature).

Comparison of hydrogen isotope exchange reactions between HTO vapor and the sodium salts of o-, m-, and p-aminobenzoic acid

International Nuclear Information System (INIS)

Okada, Minoru; Imaizumi, Hiroshi; Itoh, Tomoko

1991-01-01

Hydrogen isotope exchange reaction between HTO vapor and one of the sodium salts of o-, m-, and p-aminobenzoic acid (solid) was observed at 50 ∼ 80 degC. The acidity (acidity based on kinetic logic) for the materials at each temperature has been obtained with the A''-McKay plots based on the respective data obtained. The followings have been clarified by comparing these acidities (and the acidities obtained previously). 1) The acidity of aromatic amines can be expressed in terms of the acidity based on kinetic logic. 2) The reactivity of aromatic amine is strongly affected by both I-effect and R-effect. 3) It can be deduced that aromatic amines are more reactive than aliphatic amines. (author)

Deuterium exchange between hydrofluorocarbons and amines

International Nuclear Information System (INIS)

Hammond, W.B.; Bigeleisen, J.; Tuccio, S.A.

1983-01-01

The invention consists of a process for obtaining a compound enriched in deuterium which comprises the known method of exposing a gaseous hydrofluorocarbon to infrared laser radiation of a predetermined frequency to selectively cause a chemical reaction involving hydrofluorocarbon molecules containing deuterium without substantially affecting hydrofluorocarbon molecules not containing deuterium, thereby producing, as reaction products, a compound enriched in deuterium and hydrofluorocarbon depleted in deuterium; combined with a new method, which comprises enriching the deuterium content of the depleted hydrofluorocarbon by contacting the depleted hydrofluorocarbon with an alkali metal amide and an amine having a concentration of deuterium at least that which will yield an increase in deuterium concentration of the hydrofluorocarbon upon equilibration, whereby the amine becomes depleted in deuterium

Ruthenium-Catalyzed Aerobic Oxidation of Amines.

Science.gov (United States)

Ray, Ritwika; Hazari, Arijit Singha; Lahiri, Goutam Kumar; Maiti, Debabrata

2018-01-18

Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes

Directory of Open Access Journals (Sweden)

Kundu Kshama

2014-01-01

Full Text Available (±-Camphor-10-sulfonic acid (CSA catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthylphenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25°C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol% was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

A Bioinspired Organocatalytic Cascade for the Selective Oxidation of Amines under Air.

Science.gov (United States)

Largeron, Martine; Fleury, Maurice-Bernard

2017-05-17

A bioinspired organocatalytic cascade reaction for the selective aerobic oxidative cross-coupling of primary amines to imines is described. This approach takes advantages of commercially available pyrogallol monomeric precursor to deliver low loadings of natural purpurogallin in situ, under air. This is further engaged in a catalytic process with the amine substrate affording, under single turnover, the active biomimetic quinonoid organocatalyst and the homocoupled imine intermediate, which is then converted into cross-coupled imine after dynamic transimination. This organocatalytic cascade inspired by both purpurogallin biosynthesis and copper amine oxidases allows the aerobic oxidation of non-activated primary amines that non-enzymatic organocatalysts were not able to accomplish alone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modified solution calorimetry approach for determination of vaporization and sublimation enthalpies of branched-chain aliphatic and alkyl aromatic compounds at T = 298.15 K

International Nuclear Information System (INIS)

Varfolomeev, Mikhail A.; Novikov, Vladimir B.; Nagrimanov, Ruslan N.; Solomonov, Boris N.

2015-01-01

Highlights: • Solution enthalpies of 18 branching-chain alkyl aromatic and aliphatic compounds in cyclohexane were measured. • Group contributions to the enthalpy of solvation due to branching and substitution in carbon chain were evaluated. • Modified solution calorimetry based approach for determination of vaporization/sublimation enthalpies was proposed. • This approach provides vaporization/sublimation enthalpies directly at T = 298.15 K. • Vaporization/sublimation enthalpies of 35 branched-chain alkyl aromatic and aliphatic compounds were determined. - Abstract: The enthalpies of solution, solvation and vaporization/sublimation are interrelated values combined in the simplest thermodynamic circle. Hence, experimental determination of vaporization/sublimation enthalpy can be substituted by experimentally simpler determination of solution enthalpy when solvation enthalpy is known. Previously it was found that solvation enthalpies of a wide range of unbranched aliphatic and aromatic solutes in saturated hydrocarbons are in good linear correlation with their molar refraction values. This allows to estimate the vaporization/sublimation enthalpy of any unbranched organic compound from its solution enthalpy in saturated hydrocarbon and molar refraction. In the present work this approach was modified for determination of vaporization/sublimation enthalpy of branched-chain alkyl aromatic and aliphatic compounds. Group contributions to the enthalpy of solvation due to the branching of carbon chain were evaluated. Enthalpies of solution at infinite dilution of 18 branched-chain aliphatic and alkyl aromatic compounds were measured at T = 298.15 K. Vaporization/sublimation enthalpies for 35 branched aliphatic and alkyl aromatic compounds were determined by using modified solution calorimetry approach. These values are in good agreement with available literature data on vaporization/sublimation enthalpies obtained by conventional methods.

A rapid detection method for policy-sensitive amines real-time supervision.

Science.gov (United States)

Zhang, Haixu; Shu, Jinian; Yang, Bo; Zhang, Peng; Ma, Pengkun

2018-02-01

Many organic amines that comprise a benzene ring are policy-sensitive because of their toxicity and links to social harm. However, to date, detection of such compounds mainly relies on offline methods. This study proposes an online pptv (parts per trillion by volume) level of detection method for amines, using the recently-built vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) combined with a new doping technique. Thus, the dichloromethane doping-assisted photoionization mass spectra of aniline, benzylamine, phenethylamine, amphetamine, and their structural isomers were recorded. The dominant characteristic mass peaks for all amines are those afforded by protonated amines and the amino radical-loss. The signal intensities of the amines were enhanced by 60-130 times compared to those recorded without doping assistance. Under 10s detection time, the sensitivities of aniline and benzylamine in the gas phase were determined as 4.0 and 2.7 countspptv -1 , with limits of detection (LODs) of 36 and 22 pptv, respectively. Notably, the detection efficiency of this method can be tenfold better in future applications since the ion transmission efficiency of the mass spectrometer was intentionally reduced to ~ 10% in this study. Therefore, dichloromethane doping-assisted photoionization mass spectrometry has proven to be a highly promising on-line approach to amine detection in environmental and judicial supervision and shows great potential for application in the biological field. Copyright © 2017 Elsevier B.V. All rights reserved.

A Quantitative Structure-Property Relationship (QSPR Study of Aliphatic Alcohols by the Method of Dividing the Molecular Structure into Substructure

Directory of Open Access Journals (Sweden)

Bin Cheng

2011-04-01

Full Text Available A quantitative structure–property relationship (QSPR analysis of aliphatic alcohols is presented. Four physicochemical properties were studied: boiling point (BP, n-octanol–water partition coefficient (lg POW, water solubility (lg W and the chromatographic retention indices (RI on different polar stationary phases. In order to investigate the quantitative structure–property relationship of aliphatic alcohols, the molecular structure ROH is divided into two parts, R and OH to generate structural parameter. It was proposed that the property is affected by three main factors for aliphatic alcohols, alkyl group R, substituted group OH, and interaction between R and OH. On the basis of the polarizability effect index (PEI, previously developed by Cao, the novel molecular polarizability effect index (MPEI combined with odd-even index (OEI, the sum eigenvalues of bond-connecting matrix (SX1CH previously developed in our team, were used to predict the property of aliphatic alcohols. The sets of molecular descriptors were derived directly from the structure of the compounds based on graph theory. QSPR models were generated using only calculated descriptors and multiple linear regression techniques. These QSPR models showed high values of multiple correlation coefficient (R > 0.99 and Fisher-ratio statistics. The leave-one-out cross-validation demonstrated the final models to be statistically significant and reliable.

Dynamics of CO 2 Adsorption on Amine Adsorbents. 2. Insights Into Adsorbent Design

KAUST Repository

Bollini, Praveen

2012-11-21

Packed bed breakthrough experiments are reported for commercial zeolite 13X and 3-aminopropyl-functionalized SBA-15 silica materials with three different amine loadings. Mass and heat transfer dynamics for all four materials are modeled successfully. Amine adsorbents with open pores are found to exhibit faster mass diffusion rates compared to zeolite 13X. When amine loading is increased by coupling aminopropyl groups, premature breakthrough combined with a long tail is observed. Contrary to conventional physisorbants, finite heat losses to the column wall do not explain the long breakthrough tail. A rate model that accounts for heterogeneity in diffusion was found to accurately capture the breakthrough shape of the high loading material. Batch uptake measurements support the hypothesis that slow diffusion through the polymer phase is what hampers adsorption kinetics in the high amine loading adsorbent. The results emphasize the importance of designing materials that are not overloaded with amine sites, as excessive amine loadings can lead to depressed adsorption kinetics and premature column breakthrough. © 2012 American Chemical Society.

Reducing the energy penalty costs of postcombustion CCS systems with amine-storage.

Science.gov (United States)

Patiño-Echeverri, Dalia; Hoppock, David C

2012-01-17

Carbon capture and storage (CCS) can significantly reduce the amount of CO(2) emitted from coal-fired power plants but its operation significantly reduces the plant's net electrical output and decreases profits, especially during times of high electricity prices. An amine-based CCS system can be modified adding amine-storage to allow postponing 92% of all its energy consumption to times of lower electricity prices, and in this way has the potential to effectively reduce the cost of CO(2) capture by reducing the costs of the forgone electricity sales. However adding amine-storage to a CCS system implies a significant capital cost that will be outweighed by the price-arbitrage revenue only if the difference between low and high electricity prices is substantial. In this paper we find a threshold for the variability in electricity prices that make the benefits from electricity price arbitrage outweigh the capital costs of amine-storage. We then look at wholesale electricity markets in the Eastern Interconnect of the United States to determine profitability of amine-storage systems in this region. Using hourly electricity price data from years 2007 and 2008 we find that amine storage may be cost-effective in areas with high price variability.

Functional polyester materials with tunable degradability: Investigations into the use of reductive amination, ketoxime ether, and hydrazone linkages for functionalization, covalent stabilization and crosslinking of poly(epsilon-caprolactone) materials

Science.gov (United States)

van Horn, Brooke Angela

Aliphatic polyesters represent one class of degradable, polymeric materials that is receiving significant attention in the search for, and design of, biocompatible and bioresorbable synthetic substances. Functional and crosslinked polyesters, having potential biomedical value, are the target of many avenues of current research. This dissertation work expands the utility of a specific aliphatic polyester, poly(epsilon-caprolactone-co-2-oxepane-1,5-dione) (P(CL-co-OPD)), which contains backbone ketone units that can be reacted with various functional, nucleophilic agents. Results presented in this dissertation convey both the successes had and the challenges encountered in the employment of different "iminyl" chemistries for the synthesis of functional and crosslinked materials. Specifically, the ketone-functionalized polyester was investigated as a general substrate designed to undergo solution-state intramolecular crosslinking and functionalization upon reductive amination with 1,6-hexanediamine and hexylamine, respectively, in the presence of NaCNBH3. Through detailed analysis of the products from these reactions, and simpler systems including small molecule model compounds, the polymeric gamma-keto ester functionality was determined to be incompatible with the reductive amination chemistry, resulting in chain cleavage via intramolecular lactam formation. Subsequent investigation of ketoxime ether formation using synthetic model hydroxylamines, 1-aminooxydodecane and 1,6-bis(aminooxy)hexane, in solution and in the presence of an acid catalyst, resulted in the targeted graft and crosslinked particulate/gel materials, respectively. With the significant interest in the development of synthetic polymer materials of increasing degrees of complexity, attention has been focused on the efficient and high-yielding conversion of polyesters into multi-functional materials. Facile conjugation of aminooxy- and sulfonyl hydrazide model ligands with P(CL-co-OPD) were also

Economics of Tertiary Education - Challenges and dynamics of the public tertiary education in Albania

Directory of Open Access Journals (Sweden)

Gledian Llatja

2016-07-01

Full Text Available The tertiary education is a critic mechanism for the socio-economic progress, for individuals who aspire a brighter future and it is also considered an important catalyzer of the economic mobility (Department of Treasury and Department of Education, 2012, 2. Based on the positive role and impact that the tertiary education has on the sustainable development, President Obama once stated that it is of damage to treat education as a luxurious public service. In line with the general considerations about the tertiary education in the U.S. the parallel comparison with Albania comes as a direct interpretation of utopia in the education policy-making. As policies are usually drafted based on data and findings, in the case of Albania there is a lack of data on expenses on tertiary education as share of GDP. This stands also for the main limitation of the paper.