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Chin-Kuen Tai Pao-Ling Yeh Chun-Chi Chang Wen-Hao Chen Rong-Hou Wu Yu-Ma Chou Bo-Cheng Wang 《Research on Chemical Intermediates》2014,40(6):2355-2362
Recently, the organic synthesis and electronic device applications of π-conjugated polymer-based materials with low energy band gap (below 2 eV) and high values of incident photon to current efficiency have been presented. In the present study, the physical properties of polythiophene (PTH) and its derivative systems (PTs) were investigated as π-conjugated low energy band gap polymers. Density functional theory with periodic boundary condition (PBC), the B3LYP functional, and the 6-31G(d) basis set was applied to determine their geometric and electronic structures and corresponding energies (E HOMO, E LUMO, and E g = E LUMO ? E HOMO) from the monomer of thiophene and its derivatives for one-dimensional (1D) extension to polymer. The effects of 3-substitution in PTs including electron-donating (CH3–, C6H13–, OH–, Cl–, OCH3–, and CHO–) and electron-withdrawing groups (Cl–, CHO–, CN–, NO2–, CF3–, and COOH–) compared with PTH were investigated. According to the calculation results, PTs with electron-donating and electron-withdrawing substituents should exhibit red- and blue-shifts, respectively, compared with PTH. These calculation results show good agreement with experimental data and provide further information for molecular design considerations. 相似文献
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Effects of substituent and solvent on the structure and spectral properties of maleimide derivatives
Chin-Kuen Tai Yih-Jiun Lin Pao-Ling Yeh Yi-Ren Tzeng Yu-Ma Chou Bo-Cheng Wang 《Journal of Molecular Structure》2008,860(1-3):58-63
The maximum absorption wavelength , emission wavelength (λem) and the related oscillator strength (f) of the maleimides in the ground and first excited states were calculated by using the DFT, CIS and the time-dependent density functional theory (TD-DFT) methods, where the molecular structures were optimized by DFT/B3LYP/6-31G* calculation. Solvent effects on the maleimides were examined using the PCM simulation at DFT/B3LYP level with the 6-31G* basis set. For N-substituted maleimide, the substituent gives only a slight influence on the maleimide chromophore, while planar conformation of PhMLH leads to the improvement in π-delocalization from substituent to maleimide unit. For 3,4-substituted maleimide, the steric repulsion between substituent and maleimide chromophore influences the extent of π-delocalization and the molecular conformation. The calculated and λem of maleimides are in good agreement with the experimental data. In the gas phase, both absorption and emission peaks are red-shift as compared to the non-substituted maleimide. Under solvent environment, the more planar conformation of PhMLH shows a blue-shift in the calculated and λem as compared with other N-substituted maleimides. For 3,4-substituted maleimides, the effect of substitution produces the most significant spectral red-shift as compared to other maleimides. 相似文献
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Chang Ken-Hao Tai Chin-Kuen Chen Likey Yeh Pao-Ling Wang Bo-Cheng 《Research on Chemical Intermediates》2019,45(1):77-90
Research on Chemical Intermediates - Six D-DPI-A (D-π-A) dyes combining various arylamine electron donors (diphenylamine and triphenylamine moieties) with a fixed π-linker (DPI) and a... 相似文献
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Yu-Jung Chen Yung-Ting Lee Pao-Ling Yeh Bo-Cheng Wang 《Research on Chemical Intermediates》2017,43(6):3613-3620
Optimized geometries and electronic structures of three different symmetry shapes of nanosheet graphenes with armchair and zig-zag edges were generated by using the generalized gradient approximation/Perdew–Burke–Ernzerhof (GGA/PBE) method of density function theory (DFT) with the double-zeta polarized (DZP) basis set. Based on the results, the calculated HOMO–LUMO energy gap (Eg = LUMO–HOMO) with different symmetry shapes, and nanosheet size for with zig-zag and armchair edges were also presented. Because the p π orbital was widely localized over the sheet surface, the calculated E g decreased with increasing the sheet size. Further, the quantum mechanics calculation was used to investigate the adsorption property of the Ag atom adsorbed to the nanosheet graphene (expressed by C90H30) surface. The calculations show that the Ag atom binds to the bridge site (B site) of triangular nanosheet graphene (C90H30) as it is the most stable adsorption site compared with others, and since it has higher formation energy (ΔE) with shorter distance between the Ag atom and the graphene surface. Above all, calculations suggest that the Ag-adsorbed nanosheet graphene is a good option as an adsorbent in environmental research. 相似文献
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