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31.
Benzimidazole‐indole‐chalcone connected methacrylate‐based side chain D‐π‐A polymer and its application in organic photovoltaics
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Ramasamy Selvam Kathavarayan Subramanian 《Journal of polymer science. Part A, Polymer chemistry》2017,55(6):997-1007
Herein, we report four metal‐free organic polymethacrylates (In‐In‐BzI)PMA , (Ac‐In‐BzI)PMA , (TPA‐In‐BzI)PMA , and (Py‐In‐BzI)PMA with pendant chromophores donor‐π‐conjugated‐acceptor (D‐π‐A) molecular framework as photosensitizers for dye‐sensitized solar cells (DSSCs). In which the donor‐acceptor units are attached by an indole‐chalcone extending side chain to inhibit back electron transfer and charge recombination; the π‐linker component contains varied chalcone‐based substituents to enhance the sunlight‐harvesting ability of the solar device. Photon‐current cells based on the DSSC format were fabricated using the polymers as sensitizers. The DSSC device assembled using (TPA‐In‐BzI)PMA exhibits a considerably better IPCE peak and J–V response, with an overall power conversion efficiency of 3.70% under the illumination of AM 1.5G (100 mW cm–2). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 997–1007 相似文献
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Shape transitions as a function of angular momentum in even–even krypton isotopes with A?=?72–84 have been investigated using the cranked Nilsson–Strutinsky method. The Jacobi shape transition from noncollective oblate to super or hyperdeformed collective prolate or triaxial shape taking place in rotating nuclei as in the case of gravitating rotating stars is studied in krypton isotopes. The cranked Nilsson–Strutinsky method with a method of tuning the angular velocity to get the fixed spins is used in the calculations. Our results show that all the krypton isotopes considered in this study are the good candidates for detecting the Jacobi shape transition. Shape evolutions as a function of spin and temperature with thermal fluctuations are studied using the Landau theory of phase transitions. The constants appearing in the Landau expression for the free energy are determined by using the free energy surfaces at ω?=?0 calculated by the Strutinsky method. We show that in the presence of thermal fluctuations, the averaged shapes obtained for the considered isotopes differ from the most probable shapes. The sharp Jacobi transitions are modified due to the effect of thermal fluctuations. 相似文献
34.
A new anti-inflammatory active phenylpropenoid, (R,E)-1-[4-(3-hydroxyprop-1-enyl) phenoxyl]-3-methylbutane-2,3-diol (1), isolated from the stem wood of Zanthoxylum integrifoliolum, has been synthesized for the first time using commercially available 4-hydroxy benzaldehyde (2). The key step involves the Sharpless asymmetric dihydroxylation of olefin (3).
35.
A facile synthesis of acridinedione derived mono spiro-pyrrolidine and pyrrolizidine derivatives has been accomplished by 1,3-dipolar cycloaddition reaction. The O-acryloylacridinediones, as dipolarophiles reacted with azomethine ylide derived from di-/tri-ketones and sec-amino acids to give acridinedione derived mono spiropyrrolidine/pyrrolizidine derivatives in good yield. 相似文献
36.
J Deepa Arul Priya K Divakar M Suryia Prabha G Panneer Selvam Pennathur Gautam 《Applied biochemistry and biotechnology》2014,172(2):910-932
A new organic solvent-tolerant strain Bacillus megaterium AU02 which secretes an organic solvent-tolerant protease was isolated from milk industry waste. Statistical methods were employed to achieve optimum protease production of 43.6 U/ml in shake flask cultures. The productivity of the protease was increased to 53 U/ml when cultivated under controlled conditions in a 7-L fermentor. The protease was purified to homogeneity by a three-step process with 24 % yield and specific activity of 5,375 U/mg. The molecular mass of the protease was found to be 59 kDa. The enzyme was active over a wide range of pH (6.0–9.0), with an optimum activity at pH 7.0 and temperature from 40 to 70 °C having an optimum activity at 50 °C. The thermal stability of the enzyme increased significantly in the presence of CaCl2, and it retained 90 % activity at 50 °C for 3 h. The K m and V max values were determined as 0.722 mg/ml and 0.018 U/mg respectively. The metalloprotease exhibited significant stability in the presence of organic solvents with log P values more than 2.5, nonionic detergents and oxidising agent. An attempt was made to test the synthesis of aspartame precursor (Cbz-Asp-Phe-NH2) which was catalysed by AU02 protease in the presence of 50 % DMSO. These properties of AU02 protease make it an ideal choice for enzymatic peptide synthesis in organic media. 相似文献
37.
One-pot synthesis of well dispersed, size-controlled gold nanoparticles with the average size of 10–15 nm and luminescent
gold nanoclusters with average size of 1.7–2.0 nm were successfully achieved by thermal decomposition of gold organometallic
precursor CH3AuPPh3 in the presence of thiol surfactants in o-xylene. Only difference between the preparations of two types of Au nanoparticles is the amount of thiol surfactant employed.
The mechanistic study of formation of gold nanoparticles was carried out by analyzing the samples at different reaction time
intervals and revealed that two-staged growth process was involved. The nanoclusters showed strong red emission with the maximum
intensity at about 600 nm. The maximum room temperature photoluminescence quantum yield was measured as 1.2%. The catalytic
ability of the Au nanoclusters to promote Suzuki–Miyaura coupling involving the C–C bond formation was also investigated. 相似文献
38.
TamilSelvi Selvam Chao-Ming Chiang Kai-Ming Chi 《Journal of nanoparticle research》2011,13(8):3275-3286
Amphiphilic gold nanoclusters with the diameter of 1.8 ± 0.2 nm were prepared by decomposition of organometallic gold precursor
CH3AuPPh3 in the presence of mercaptoacids in o-xylene. Self-assembly of the 16-mercaptohexadecanoic acid protected gold clusters led to the formation of the nanosheets
consisted of aligned gold clusters. The hydrogen bonding between the carboxylic groups attached on the adjacent gold clusters
likely drives the self-assembly. This phenomenon was cross-verified by employing the preheated mercaptoacid-amine surfactant
system where a part of the mercaptoacids and amines were converted into –NH3
+–−OOC– ion pair and interrupting a part of the hydrogen bonding sites to lead to the reduction in the size of the structures
from nanosheets to nanobelts. Interestingly, we found the dependency of the luminescent properties on the extent of maintaining
the self-assembly of the clusters intern dictated by the surfactants. 相似文献
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Bhupendra Adhikari Mohsen Teimouri James W. Akin Dr. Selvam Raju Prof. Dr. Sean L. Stokes Prof. Dr. Joseph P. Emerson 《European journal of organic chemistry》2023,26(40):e202300620
An efficient copper(II) N-heterocyclic carbene (NHC) complex with an NCN coordination mode was optimized to catalyze the Chan–Evans-Lam (CEL) cross-coupling reaction of imidazole and other N-heterocyclic nucleophiles with arylboronic acid. This air-stable copper catalyst shows robust catalytic performance and tolerates a diverse array of functional groups on both the N-nucleophile and arylboronic acid coupling partners in C−N bond forming reactions with up to 95 % yield. Formation of the Cu−NHC complex in situ generated similar catalytic performance for CEL coupling. Alternative metal ions (Mn2+, Fe2+, Co2+, Ni2+, Zn2+, Ru2+, and Pd2+) were also screened in the presence of the NHC precursor as CEL catalysts. 相似文献