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排序方式: 共有87条查询结果,搜索用时 31 毫秒
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A novel liquid scintillator system using metal β-diketonate chemistry based on loadings of indium, a target of current interest in low energy solar neutrino detection, is developed. The optical absorption, fluorescence and scintillation properties for this new system are described. The scintillation light output as found from the irradiation by low energy gamma-rays is presented. Notable light yields are found. 相似文献
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In an attempt to develop a method for the general preparation of 1-alkenesulfenamides, some N,N-bis(trimethylsilyl)-1-alkenesulfenamides (4) were converted to a number of nitrogen functionalized analogs through desilylation and acylation procedures. Mono- and dibenzoylated derivatives 5aand 6a did not undergo transamination reactions with simple amines. Transamination reactions could be achieved once compounds 4 were converted to thiophthalimides 7. The transamination products 8 are unstable to chromatography, but could be oxidized to 1-alkenesulfonamides 9 using MCPBA. Some of the sulfenamides 8 may be stable to distillation. 3-(Alkenylthioimino)phthalides 11, isomers of thiophthalimides 7, also react with amines, but the process of ring opening accompanies transamination. It was found that the transamination reactions of 11 probably involve the intermediacy of isomers 7. 相似文献
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Devendra KC Deb Kumar Shah M. Shaheer Akhtar Mira Park Chong Yeal Kim O-Bong Yang Bishweshwar Pant 《Molecules (Basel, Switzerland)》2021,26(11)
This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (η = 15%), and quantum efficiency (QE~85%) were achieved at a carrier lifetime of 1 × 103 μs and a doping concentration of 1 × 1017 cm−3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 μm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication. 相似文献
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Phenothiazine–BODIPY–Fullerene Triads as Photosynthetic Reaction Center Models: Substitution and Solvent Polarity Effects on Photoinduced Charge Separation and Recombination 下载免费PDF全文
Chandra B. KC Gary N. Lim Dr. Vladimir N. Nesterov Prof. Dr. Paul A. Karr Prof. Dr. Francis D'Souza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(51):17100-17112
Novel photosynthetic reaction center model compounds of the type donor2–donor1–acceptor, composed of phenothiazine, BF2‐chelated dipyrromethene (BODIPY), and fullerene, respectively, have been newly synthesized using multistep synthetic methods. X‐ray structures of three of the phenothiazine‐BODIPY intermediate compounds have been solved to visualize the substitution effect caused by the phenothiazine on the BODIPY macrocycle. Optical absorption and emission, computational, and differential pulse voltammetry studies were systematically performed to establish the molecular integrity of the triads. The N‐substituted phenothiazine was found to be easier to oxidize by 60 mV compared to the C‐substituted analogue. The geometry and electronic structures were obtained by B3LYP/6‐31G(dp) calculations (for H, B, N, and O) and B3LYP/6‐31G(df) calculations (for S) in vacuum, followed by a single‐point calculation in benzonitrile utilizing the polarizable continuum model (PCM). The HOMO?1, HOMO, and LUMO were, respectively, on the BODIPY, phenothiazine and fullerene entities, which agreed well with the site of electron transfer determined from electrochemical studies. The energy‐level diagram deduced from these data helped in elucidating the mechanistic details of the photochemical events. Excitation of BODIPY resulted in ultrafast electron transfer to produce PTZ–BODIPY.+–C60.?; subsequent hole shift resulted in PTZ.+–BODIPY–C60.? charge‐separated species. The return of the charge‐separated species was found to be solvent dependent. In nonpolar solvents the PTZ.+–BODIPY–C60.? species populated the 3C60* prior to returning to the ground state, while in polar solvent no such process was observed due to relative positioning of the energy levels. The 1BODIPY* generated radical ion‐pair in these triads persisted for few nanoseconds due to electron transfer/hole‐shift mechanism. 相似文献
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Shekhar KC Roshan K. Dhungana Namrata Khanal Ramesh Giri 《Angewandte Chemie (International ed. in English)》2020,59(21):8047-8051
We report a Ni‐catalyzed regioselective α‐carbonylalkylarylation of vinylarenes with α‐halocarbonyl compounds and arylzinc reagents. The reaction works with primary, secondary, and tertiary α‐halocarbonyl molecules, and electronically varied arylzinc reagents. The reaction generates γ,γ‐diarylcarbonyl derivatives with α‐secondary, tertiary, and quaternary carbon centers. The products can be readily converted to aryltetralones, including a precursor to Zoloft, an antidepressant drug. 相似文献
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