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Sample records for quaterphenyls

  1. [Analysis of polychlorinated quaterphenyls in Yusho diagnosis].

    Science.gov (United States)

    Ashizuka, Yuki; Nakagawa, Reiko; Hirakawa, Hironori; Hori, Tsuguhide; Iida, Takao

    2005-05-01

    The polychlorinated quaterphenyl (PCQ) concentrations in the blood are important discriminative parameters in Yusho patients. In this study, the analytical method of PCQ was improved, and a high speed and precision analysis could be achieved. A recovery test showed satisfactory recoveries of 99.5% (RSD4.8%, n = 5). Using this method, the authors analyzed 62 blood samples which were collected from the 2004 annual inspection for Kanemi rice oil poisoning. PCQ was detected in 20 blood samples (ranging from 0.03 to 4.15 ng/g). The average concentration was 2.07 ng/g in the pattern A (typical Yusho patients), 0.76 ng/g in the pattern B, 0.18 ng/g in the pattern BC and 0.01 ng/g in the pattern C, respectively.

  2. [Analysis of polychlorinated quaterphenyls in Yusho diagnosis in 2005].

    Science.gov (United States)

    Ashizuka, Yuki; Nakagawa, Reiko; Hirakawa, Hironori; Hori, Tsuguhide; Kajiwara, Jumboku; Iida, Takao; Yoshimura, Takesumi

    2007-05-01

    The polychlorinated quaterphenyl (PCQ) concentrations in the blood are important discriminative parameters in Yusho patients. The blood samples of 81 persons were analyzed for PCQ in the 2005 annual inspection for Kanemi rice oil poisoning. PCQ was detected in 28 blood samples (ranging from 0.02 to 4.05 ppb). The means of PCQ concentration in the blood were 1.80 ppb (0.33-4.05 ppb) in pattern A, 0.71 ppb (PCQ was still present at high concentration in the blood of patterns A and B. Since PCQ concentration is a useful diagnostic criteria, it is important to follow up on this survey of blood PCQ levels.

  3. Mesomorphic, dielectric, and optical properties of fluorosubstituted biphenyls, terphenyls, and quaterphenyls

    Science.gov (United States)

    Kula, P.; Spadło, A.; Dziaduszek, J.; Filipowicz, M.; Dąbrowski, R.; Czub, J.; Urban, S.

    2008-12-01

    Compounds with moderate and large negative dielectric anisotropy (Δɛ) are very attractive liquid crystal (LC) for vertical alignment mode (VA). Materials with such properties can be achieved by lateral substitution of a polar group into a mesogenic molecule. We synthesized some new LC materials with a negative value of Δɛ, a moderately high birefringence (Δn), and a low viscosity. The mesomorphic and physical behaviour of the novel biphenyls, terphenyls and quaterphenyls fluorosubstituted in the rigid core and also with fluorinated alkyl and alkoxy chains are investigated. The prepared series of four LC compounds are promising for new LC mixtures for various applications. Examples of nematic mixtures with Δɛ˜-3.25 will be presented.

  4. p-Quaterphenyls laterally substituted with a dimesitylboryl group: a promising class of solid-state blue emitters.

    Science.gov (United States)

    Fu, Guang-Liang; Zhang, Hong-Yu; Yan, Yi-Qiao; Zhao, Cui-Hua

    2012-02-17

    A new family of p-quaterphenyls 1-6 laterally substituted with a bulky electron-accepting dimesitylboryl group has been designed and synthesized. These compounds were characterized by X-ray crystallography, UV-vis and fluorescence spectroscopy, and DFT calculations as well as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and cyclic voltammetry (CV). X-ray single-crystal analysis revealed that the p-quaterphenyl main chain framework exhibits a twisted structure due to the steric effect of the lateral boryl group, and the intermolecular interactions are effectively suppressed in the solid state. Despite the significantly twisted main-chain structure, these molecules still display efficient intramolecular charge-transfer emissions with large Stokes shifts. An intriguing finding is that all these molecules show bright fluorescence with good to excellent quantum yields in the blue region in the solid state. In addition, the two representative p-quaterphenyls 3 and 4 containing both the electron-accepting boryl group and the electron-donating carbazolyl (3) or diphenylamino group (4) possess high thermal stability and good oxidation-reduction reversibility, which together with their excellent solid-state fluorescence efficiency make them promising bipolar transporting blue emitters.

  5. [The rapid analysis of polychlorinated quaterphenyls in blood using different diameter capillary column with the high-resolution gas chromatograph high-resolution mass spectrometer].

    Science.gov (United States)

    Yasutake, Daisuke; Ashizuka, Yuki; Hori, Tsuguhide; Kurokawa, Youichi; Kajiwara, Jumboku; Hirata, Teruaki; Ishiguro, Yasuhisa; Iida, Takao; Uchi, Hiroshi; Furue, Masutaka

    2011-04-01

    The polychlorinated quaterphenyl (PCQ) concentrations in blood are important discriminative parameters in yusho patient. In this study, a rapid analytical method for PCQ using different diameter capillary column (rapid-Rtx65TG) with high-resolution gas chromatograph high-resolution mass spectrometer (HRGC/HRMS) instead of the gas chromatograph electron capture detector (ECD/GC) was developed. Using different diameter capillary columns, the analysis time of the HRGC/HRMS was drastically shortened, and the detection sensitivity was improved. In the rapid-Rtx65TG column, a small-bore capillary column (length 1m, I.D. 0.1mm) was connected with the inlet side of the GC, and behind that column, a large-bore capillary column (length 15mm, I.D. 0.53mm) for octadecachloroquaterphenyl (ODCQ) analysis was connected. In the HRGC/HRMS measurement of ODCQ by the rapid-Rtx65TG column, the minimum limit of detection for the apparatus was 0.4 pg, and the minimum limit of determination for the blood was 0.008 ppb. On ECD/GC in the conventional method and HRGC/HRMS in this study, the PCQ concentration in blood including yusho patients and yusho suspected persons was almost equivalent.

  6. A comparative study on polychlorinated biphenyls (PCB) and polychlorinated quaterphenyls (PCQ) concentrations in subcutaneous fat tissue, blood and hair of patients with yusho and normal control in Nagasaki prefecture.

    Science.gov (United States)

    Ohgami, T; Nonaka, S; Murayama, F; Yamashita, K; Irifune, H; Watanabe, M; Tsukazaki, N; Tanaka, K; Yoshida, H; Rikioka, Y

    1989-05-01

    The relationship between PCB and PCQ concentrations in the blood, subcutaneous fat tissue and hair was investigated in this study. PCB and PCQ concentrations in twenty four patients with PCB poisoning (yusho) and 59 normal controls were analyzed. The alkaline decomposition method described in the official standard analytical methods for the isolation of PCB and PCQ fractions was used. The mean value of PCB concentrations was 2.43 ppb, CB% ratio was 0.69 and the PCQ concentration in the blood of the control group was too low to be detected by our analysis. On the other hand, the PCB concentration and CB% ratio in the yusho group were two times higher than those in the control group. The mean value of PCQ concentration was 1.34 ppb in the yusho group although it was below the level of detection in the control group. The mean PCB concentration in the hair of patients with yusho was 28.92 ppb, and 8.06 ppb in the control group. CB% ratio in the hair of patients with yusho was two times higher than that in the control group. The mean value of PCQ concentration in the hair of patients with yusho was 0.55 ppb although it was not detected in the control group. The PCB and PCQ concentrations in the hair were not greatly elevated when compared with those in the subcutaneous fat tissue. However, the hair is an excellent sample for the detection of these chemicals because it can be collected simply without operation.

  7. Combinatorial parallel synthesis and automated screening of a novel class of liquid crystalline materials.

    Science.gov (United States)

    Deeg, Oliver; Kirsch, Peer; Pauluth, Detlef; Bäuerle, Peter

    2002-12-07

    Combinatorial parallel synthesis has led to the rapid generation of a single-compound library of novel fluorinated quaterphenyls. Subsequent automated screening revealed liquid crystalline (LC) behaviour and gave qualitative relationships of molecular structures and solid state properties.

  8. 4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

    2017-01-01

    Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... beyond 1 nm. This work demonstrates a route for guiding the integration of exciton blocking layers in organic solar cell devices....

  9. Stimulated emission of ultraviolet radiation by vapors of complex molecules

    Energy Technology Data Exchange (ETDEWEB)

    Barkova, L.A.; Gruzinskii, V.V.; Danilova, V.I.; Degtyarenko, K.M.; Kopylova, T.N.; Kuznetsov, A.L.

    1981-08-01

    Lasing was observed in vapors of new organic compounds: para-terphenyl, 2-phenylbenzoxazole, 2-(n-tolyl) benzoxazole, 2-(n-methoxyphenyl) benzoxazole, 2-(n-dimethylaminophenyl) benzoxazole, 2-biphenylbenzoxazole, 2-(..cap alpha..-naphthyl) benzoxazole, and also 1,4-di(n-phenylethynyl) benzole, and para-quaterphenyl pumped transversely by XeCl excimer laser radiation at lambda/sub p/ = 308 nm. The lasing bands without tuning covered the 330--370 nm range. The shortest-wavelength maximum (333.5 nm) was observed for 2-(n-methoxyphenyl) benzoxazole. An analysis was made of the lasing ability of the molecules.

  10. High Birefringence Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Jakub Herman

    2013-09-01

    Full Text Available Liquid crystals, compounds and mixtures with positive dielectric anisotropies are reviewed. The mesogenic properties and physical chemical properties (viscosity, birefringence, refractive indices, dielectric anisotropy and elastic constants of compounds being cyano, fluoro, isothiocyanato derivatives of biphenyl, terphenyl, quaterphenyl, tolane, phenyl tolane, phenyl ethynyl tolane, and biphenyl tolane are compared. The question of how to obtain liquid crystal with a broad range of nematic phases is discussed in detail. Influence of lateral substituent of different kinds of mesogenic and physicochemical properties is presented (demonstrated. Examples of mixtures with birefringence ∆n in the range of 0.2–0.5 are given.

  11. Perfect spin filtering by symmetry in molecular junctions

    Science.gov (United States)

    Li, Dongzhe; Dappe, Yannick J.; Smogunov, Alexander

    2016-05-01

    Obtaining highly spin-polarized currents in molecular junctions is crucial and important for nanoscale spintronics devices. Motivated by our recent symmetry-based theoretical argument for complete blocking of one spin conductance channel in model molecular junctions [A. Smogunov and Y. J. Dappe, Nano Lett. 15, 3552 (2015), 10.1021/acs.nanolett.5b01004], we explore the generality of the proposed mechanism and the degree of achieved spin-polarized current for realistic molecular junctions made of various ferromagnetic electrodes (Ni, Co, Fe) connected by different molecules (quaterthiophene or p -quaterphenyl). A simple analysis of the spin-resolved local density of states of a free electrode allowed us to identify the Fe(110) as the most optimal electrode, providing perfect spin filtering and high conductance at the same time. These results are confirmed by ab initio quantum transport calculations and are similar to those reported previously for model junctions. It is found, moreover, that the distortion of the p -quaterphenyl molecule plays an important role, reducing significantly the overall conductance.

  12. Chain-length-dependent intermolecular packing in polyphenylenes: a high pressure study

    CERN Document Server

    Heimel, G; Oehzelt, M; Hummer, K; Koppelhuber-Bitschnau, B; Porsch, F; Ambrosch-Draxl, C; Resel, R

    2003-01-01

    We report on pressure-induced structural changes in crystalline oligo(para-phenylenes) containing two to six phenyl rings. The results are discussed with particular emphasis put on the implications these changes in intermolecular distances and molecular arrangement have on important bulk properties of this class of materials, such as optical response and charge transport. We performed energy dispersive x-ray diffraction in a systematic study on polycrystalline powders of biphenyl, para-terphenyl, p-quaterphenyl, p-quinquephenyl and p-sexiphenyl under hydrostatic pressure up to 60 kbar. Revisiting the crystal structures at ambient conditions reveals details in the packing principle. A linear relationship between the density at ambient conditions and the number of phenyl rings is found. High pressure data not only yields pressure-dependent lattice parameters and hints towards pressure-induced changes in the molecular arrangement but also allows for an analysis of the equations of state of these substances as a ...

  13. 2005年度油症検診における血液中ポリ塩化クアテルフェニルの分析

    OpenAIRE

    芦塚, 由紀; 中川, 礼子; 平川, 博仙; 堀, 就英; 梶原, 淳睦; 飯田, 隆雄; 吉村, 健清

    2007-01-01

    The polychlorinated quaterphenyl (PCQ) concentrations in the blood are important discriminative parameters in Yusho patients. The blood samples of 81 persons were analyzed for PCQ in the 2005 annual inspection for Kanemi rice oil poisoning. PCQ was detected in 28 blood samples (ranging from 0.02 to 4.05ppb). The means of PCQ concentration in the blood were 1.80ppb (0.33-4.05ppb)in pattern A,0.71ppb (<0.02-2.26ppb)in pattern B,0.03ppb (<0. 02-0.14ppb) in pattern BC and 0.02ppb (<0.02-0.45ppb) ...

  14. NRL-ATM extreme ultraviolet solar image TV monitor flown on Skylab

    Science.gov (United States)

    Crockett, W. R.; Purcell, J. D.; Schumacher, R. J.; Tousey, R.; Patterson, N. P.

    1977-01-01

    An instrument for recording extreme ultraviolet television images of the sun was flown in the Apollo Telescope Mount on Skylab. Solar radiation in the 171-630 A wavelength range, defined by the transmission band of three thin-film aluminum filters, was focused onto a p-quaterphenyl photon conversion layer by a platinum-coated mirror at normal incidence. The conversion layer was attached to the faceplate of a low light level SEC vidicon. An onboard video monitor enabled the Skylab crews to observe the images in real-time and to identify and follow the development of solar features. Images were also transmitted to the mission control center, where they were used in planning the ATM observing schedule.

  15. 4P-NPD ultra-thin films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    Science.gov (United States)

    Patil, Bhushan R.; Liu, Yiming; Qamar, Talha; Rubahn, Horst-Günter; Madsen, Morten

    2017-09-01

    Exciton blocking effects from ultra-thin layers of N,N‧-di-1-naphthalenyl-N,N‧-diphenyl [1,1‧:4‧,1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD) were investigated in small molecule-based inverted organic solar cells (OSCs) using tetraphenyldibenzoperiflanthene as the electron donor material and fullerene (C70) as the electron acceptor material. The short-circuit current density (J SC) and power conversion efficiency (PCE) of the optimized OSCs with 0.7 nm thick 4P-NPD were approximately 16% and 24% higher, respectively, compared to reference devices without exciton blocking layers (EBLs). Drift diffusion-based device modeling was conducted to model the full current density-voltage (JV) characteristics and external quantum efficiency spectrum of the OSCs, and photoluminescence measurements were conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies of the device behaviors and exciton generation rates and densities in the active layer for different 4P-NPD layer thicknesses were conducted, in order to gain a complete understanding of the observed increase in PCE for 4P-NPD layer thicknesses up to 1 nm, and the observed decrease in PCE for layer thicknesses beyond 1 nm. This work demonstrates a route for guiding the integration of EBLs in OSC devices.

  16. Efficient Hybrid White Organic Light-Emitting Diodes for Application of Triplet Harvesting with Simple Structure

    CERN Document Server

    Hwang, Kyo Min; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Jwajin; Yoon, Seung Soo; Kim, Young Kwan

    2016-01-01

    In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with simple structure. All the hole transporting material and host in emitting layer (EML) of devices were utilized with same material by using N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine (4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated three color with blue fluorescent and green, red phosphorescent materials. We was investigated the effect of triplet harvesting (TH) by exciton generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs were dominant hole mobility, therefore exciton generation zone was expected in EML. Additionally, we was optimization thickness of hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. Simple hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum external quantum efficiency of 11.2%. Commission Internatio...

  17. Reassembling and testing of a high-precision heat capacity drop calorimeter. Heat capacity of some polyphenyls at T = 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luis M.N.B.F., E-mail: lbsantos@fc.up.pt [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Rocha, Marisa A.A.; Rodrigues, Ana S.M.C. [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Stejfa, Vojtech; Fulem, Michal [Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, CZ-166 28 Prague 6 (Czech Republic); Bastos, Margarida [Centro de Investigacao em Quimica, Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal)

    2011-12-15

    Graphical abstract: Highlights: > We present the reassembling, improvement and testing of a high-precision C{sub p} drop calorimeter. > The apparatus was tested, using benzoic acid and hexafluorobenzene. > The high sensitivity of the apparatus is comparable to the one obtained in adiabatic calorimetry. > Heat capacities at T = 298.15 K of some polyphenyls were measured. > Subtle heat capacity differences among position isomers (ortho, meta, para) were detected. - Abstract: The description of the reassembling and testing of a twin heat conduction, high-precision, drop microcalorimeter for the measurement of heat capacities of small samples are presented. The apparatus, originally developed and used at the Thermochemistry Laboratory, Lund, Sweden, has now been reassembled and modernized, with changes being made as regarding temperature sensors, electronics and data acquisition system. The apparatus was thereafter thoroughly tested, using benzoic acid and hexafluorobenzene as test substances. The accuracy of the C{sub p,m}{sup 0} (298.15 K) data obtained with this apparatus is comparable to that achieved by high-precision adiabatic calorimetry. Here we also present the results of heat capacity measurements on of some polyphenyls (1,2,3-triphenylbenzene, 1,3,5-triphenylbenzene, p-terphenyl, m-terphenyl, o-terphenyl, p-quaterphenyl) at T = 298.15 K, measured with the renewed high precision heat capacity drop calorimeter system. The high resolution and accuracy of the obtained heat capacity data enabled differentiation among the ortho-, meta-, and para-phenyl isomers.

  18. An improved performance of copper phthalocyanine OFETs with channel and source/drain contact modifications

    Science.gov (United States)

    Huanqin, Dang; Xiaoming, Wu; Xiaowei, Sun; Runqiu, Zou; Ruochuan, Zhang; Shougen, Yin

    2015-10-01

    We report an effective method to improve the performance of p-type copper phthalocyanine (CuPc) based organic field-effect transistors (OFETs) by employing a thin para-quaterphenyl (p-4p) film and simultaneously applying V2O5 to the source/drain regions. The p-4p layer was inserted between the insulating layer and the active layer, and V2O5 layer was added between CuPc and Al in the source-drain (S/D) area. As a result, the field-effect saturation mobility and on/off current ratio of the optimized device were improved to 5 × 10-2 cm2/(V·s) and 104, respectively. We believe that because p-4p could induce CuPc to form a highly oriented and continuous film, this resulted in the better injection and transport of the carriers. Moreover, by introducing the V2O5 electrode's modified layers, the height of the carrier injection barrier could be effectively tuned and the contact resistance could be reduced. Project supported by the National Natural Science Foundation of China (No. 60676051), the National High Technology Research and Development Program of China (No. 2013A A014201), the Scientific Developing Foundation of Tianjin Education Commission (No. 2011ZD02), the Key Science and Technology Support Program of Tianjin (No. 14ZCZDGX00006), and the Foundation of Key Discipline of Material Physics and Chemistry of Tianjin.

  19. A cohort study on mortality and exposure to polychlorinated biphenyls.

    Science.gov (United States)

    Hsieh, S F; Yen, Y Y; Lan, S J; Hsieh, C C; Lee, C H; Ko, Y C

    1996-01-01

    In 1979, an outbreak of food poisoning ("Yu-Cheng") occurred in Central Taiwan, ROC, involving more than 2000 people. The event was caused by ingestion of rice oil contaminated with polychlorinated derivatives of biphenyls, dibenzofurans, and quaterphenyls. A retrospective cohort study on mortality was undertaken, and possible long-term health effects in the affected individuals were studied. The mortality experience of 1940 victims (929 males, 1011 females) between 1980 and 1991 was compared with the expected numbers, which were calculated from national and local mortality rates. By the end of 1991, 102 deaths were identified, thus producing a standardized mortality ratio (SMR) of overall mortality of 0.99 for males and 1.34 for females. Total cancer mortality was lower than in each comparison group. Mortality from liver diseases was elevated significantly (SMR = 3.22), especially during the first 3 y after the food-poisoning event (SMR = 10.76). Increased clinical severity of polychlorinated biphenyl intoxication was associated with increased mortality from all causes and from liver diseases. In summary, there was a positive association between mortality and intoxication dose, and severe polychlorinated biphenyl poisoning acutely affected mainly the liver. A continued follow-up of this cohort would be valuable in the study of long-term health effects of polychlorinated biphenyl poisoning.

  20. Liver function tests in workers with occupational exposure to polychlorinated biphenyls (PCBs): comparison with Yusho and Yu-Cheng

    Energy Technology Data Exchange (ETDEWEB)

    Fischbein, A.

    1985-05-01

    The results of liver function tests in a population manufacturing capacitors and transformers are presented. Two clinical field examinations were performed, one in 1976 when PCBs were still used in the manufacturing of the electrical equipment and one at the end of 1979, 2.5 years after discontinuation of PCBs use. A low prevalence of abnormal liver function tests was found and mean values for all tests were within normal laboratory ranges. At the initial examination, weak, but statistically significant correlations were found between log LDH and plasma levels of log HPCB (higher chlorinated congeners of polychlorinated biphenyls) and log TPCB (total polychlorinated biphenyls) among the female workers, while log el-GTP correlated significantly only with log HPCB among the male workers. A significant increase to abnormal levels of el-GTP was noted at the follow-up examination in both male and female workers, and preliminary results indicate significant correlations between el-GTP and serum levels of PCBs among the male workers. These findings are in accordance with previously reported data on populations occupationally exposed to PCBs, but differ from hepatic biochemistry findings in accidental poisonings due to ingestion of cooking oil contaminated with PCBs and related compounds, i.e., polychlorinated dibenzofurans (PCDFs) and polychlorinated quaterphenyls (PCQs). Hence, the importance of considering the related compounds as etiologic factors in PCB poisoning is emphasized.

  1. Fluorescence and laser properties of D2-, C2- and D3 symmetry series oligophenylenes.

    Science.gov (United States)

    Mabbs, R; Nijegorodov, N; Downey, W S

    2003-04-01

    The fluorescence and laser properties of ten aromatic compounds, specially chosen from the p-oligophenylenes (D(2) symmetry) or m-oligophenylenes (C(2) or D(3) symmetry) are studied experimentally (at 293 K) and quantum chemically. The quantum yields, gamma and the decay times, tau(f) of fluorescence are measured for deaerated and non-deaerated cyclohexane solutions. The oscillator strengths, f(e) of the S(0)-->S(p) (1A-->(1)L(a)) and S(0)-->S(alpha) (1A-->(1)L(b)) transitions, fluorescence, k(f) and intersystem crossing, k(ST), rate constants, and natural lifetimes, tau(0)(T) are calculated. The lowest 1L(b), 1L(a) and 3L(b) (77 K) levels are determined. It is found that all p-oligophenylenes from p-terphenyl onwards are excellent, photochemically stable laser dyes although the solubility in this series decreases dramatically. On the basis of trends observed in p-oligophenylenes (D(2)-series) and on the properties of the experimentally studied m-oligophenylenes of the C(2)- and D(3)-series, the fluorescence and laser properties of other compounds from these series are estimated/predicted. It is shown, for the first time, that m-oligophenylenes of the C(2)-series, from 1,3-di(p-terphenyl)benzene will acquire fluorescence of 1L(a)-->(1)A nature and could be extremely effective laser dyes. It is also shown that m-oligophenylenes of the D(3)-series, from 1,3,5-tri(p-quaterphenyl)benzene will also acquire 1L(a)-->(1)A nature fluorescence and laser ability, although this would not be as good as that of compounds in the C(2)-series. It is concluded that m-oligophenylenes can be used not only for passive mode locking but some may also be used as laser dyes and scintillators. The results obtained are important for various practical purposes and theoretical considerations.

  2. The Construction of Metal-Organic Framework with Active Backbones by the Utilization of Reticular Chemistry

    Science.gov (United States)

    Choi, Eunwoo

    With the principles of reticular chemistry, metal-organic frameworks with ultra-high porosity, chiral-recognition unit as a chiral stationary phase, metalloporhyrins for enhanced hydrogen adsorption and an intrinsic conductivity to form porous conductors, have been prepared. This dissertation presents how the principles of reticular chemistry were utilized to achieve in the preparations of metal-organic frameworks with a large surface area and active backbones. Through the simple isoreticular (having the same framework topology) expansion from MOF-177 composed with 1,3,5-tris(4'-carboxyphenyl-)benzene (BTB3-) as the strut; MOF-200 was prepared with 4,4',4"-(benzene-1,3,5-triyl-tris(benzene-4,1-diy1))tribenzoic acid an extension from BTB3- by a phenylene unit to yield one of the most porous MOFs with a Langmuir surface area of 10,400 m2. and the lowest density of 0.22 cm3.g-1. A successful thermal polymerization reaction at 325 °C inside of the pores of highly porous MOF, MOF-177, was performed and verified the integrity of the MOF structure even after the thermal reaction. 1,4-Diphenylbutadiyne that is known to polymerize upon heating to form a conjugated backbone was impregnated via solution-diffusion into MOF-177 and then subsequently polymerized by heat to form polymer impregnated MOF-177. Characterization was carried out using powder X-ray diffraction and volumetric sorption analyzer. MOF-1020 with a linear quaterphenyl dicarboxylate-based strut was designed to contain a chiral bisbinaphthyl crown-ether moiety for alkyl ammonium resolution was precisely placed into a Zn4O(CO2)6-based cubic MOF structure. Unfortunately, the chiral resolution was not achieved due to the sensitivity and the pore environment of MOF-1020. However, an interesting phenomenon was observed, where the loss of crystallinity occurs upon solvent removal while the crystallites remain shiny and crystalline, but it readily is restored upon re-solvation of the crystallites. This rare