The absorption and emission spectra, as well as the photolysis mechanism of p-phenylbenzoyl methanthiol in methanol and in gas phase were elucidated in detail based on the molecular structures of the ground states, ex...The absorption and emission spectra, as well as the photolysis mechanism of p-phenylbenzoyl methanthiol in methanol and in gas phase were elucidated in detail based on the molecular structures of the ground states, excited states and their spectroscopic characters. The TD-M062 X calculations demonstrate that the S_1 state in gas phase will decompose into SH and p-phenylbenzoyl radical via a barrierless process, but the T_1 and T_2 do not photolyze. By adding 1 and 2 methanol molecules onto p-phenylbenzoyl methanthiol, the CPCM model can perfectly describe the solvation effects of methanol. Methanol may stabilize the excitation states, but also protects the resulting radical products from recombination.展开更多
Aromatic systems like phenol, diphenol, cyano benzene, chloro benzene, aniline etc shows effective π-π stacking interactions, long range van der Waals forces;ion-π interactions etc. and these forces of interactions...Aromatic systems like phenol, diphenol, cyano benzene, chloro benzene, aniline etc shows effective π-π stacking interactions, long range van der Waals forces;ion-π interactions etc. and these forces of interactions play an crucial role in the stability of stacked π-dimeric system. On the other hand, substituents and conformational change in the stacked dimmers of aromatic system may also change the stability of different stacked dimers. In this current study, stacked phenolic dimmers (both phenol and diphenol) have been taken for investigation of the stacking π-π interaction. But, the stacking interactions are also greatly affected by the conformational change with internal rotation (i.e. dihedral angle, φ) between the stacked dimers. It is generally accepted that larger basis sets are required for the highly accurate calculation of interaction energies for any stacked aromatic models. But, it has recently been reported that M062X/6-311++G(d,p) basis set is effectively better than that of B3LYP/6-311++G(d,p) for determining the interaction energies for any kind of long range interaction in aromatic systems. Therefore, all the calculations were carried out by using M062X/6-311++G(d,p) basis set. However, in most of the cases the calculated π-π stacking interaction energies show almost same result for both DFT and ab initio methods.展开更多
为探索3,4-二硝基吡唑高能熔铸炸药中分子…阳离子和阳离子…σ相互作用之间的关系,本论文借助M062X方法,在6-311++G(2d,p)基组水平上研究了Na^+…3,4-二硝基吡唑…H_2O三聚体协同效应,对其进行了分子间相互作用能和协同效应的计算与分...为探索3,4-二硝基吡唑高能熔铸炸药中分子…阳离子和阳离子…σ相互作用之间的关系,本论文借助M062X方法,在6-311++G(2d,p)基组水平上研究了Na^+…3,4-二硝基吡唑…H_2O三聚体协同效应,对其进行了分子间相互作用能和协同效应的计算与分析,然后建立了分子间距离R(R_(ternary)-R_(binary))与~2ρ(▽~2ρBCP_(ternary)-▽~2ρBCP_(binary))的线性关系。结果表明,线状三聚体结构中发生了协同效应,而在环状结构中出现了反协同效应。分子间距离R(R_(ternary-)R_(binary))与~2ρ(▽~2ρBCP_(ternary)-▽~2ρBCP_(binary))具有良好的线性关系(R^2=0.992)。AIM(atoms in molecules)与电子云密度转移分析佐证了协同效应的存在。展开更多
基金jointly supported by the National Natural Science Foundation of China(Nos.21502136 and 51702228)the Natural Science Foundation of Shandong Province(ZR2017LB010)the Scientific Research Initial Foundation for Introduction of Talent of Taishan University(Y-01-2013010)
文摘The absorption and emission spectra, as well as the photolysis mechanism of p-phenylbenzoyl methanthiol in methanol and in gas phase were elucidated in detail based on the molecular structures of the ground states, excited states and their spectroscopic characters. The TD-M062 X calculations demonstrate that the S_1 state in gas phase will decompose into SH and p-phenylbenzoyl radical via a barrierless process, but the T_1 and T_2 do not photolyze. By adding 1 and 2 methanol molecules onto p-phenylbenzoyl methanthiol, the CPCM model can perfectly describe the solvation effects of methanol. Methanol may stabilize the excitation states, but also protects the resulting radical products from recombination.
文摘Aromatic systems like phenol, diphenol, cyano benzene, chloro benzene, aniline etc shows effective π-π stacking interactions, long range van der Waals forces;ion-π interactions etc. and these forces of interactions play an crucial role in the stability of stacked π-dimeric system. On the other hand, substituents and conformational change in the stacked dimmers of aromatic system may also change the stability of different stacked dimers. In this current study, stacked phenolic dimmers (both phenol and diphenol) have been taken for investigation of the stacking π-π interaction. But, the stacking interactions are also greatly affected by the conformational change with internal rotation (i.e. dihedral angle, φ) between the stacked dimers. It is generally accepted that larger basis sets are required for the highly accurate calculation of interaction energies for any stacked aromatic models. But, it has recently been reported that M062X/6-311++G(d,p) basis set is effectively better than that of B3LYP/6-311++G(d,p) for determining the interaction energies for any kind of long range interaction in aromatic systems. Therefore, all the calculations were carried out by using M062X/6-311++G(d,p) basis set. However, in most of the cases the calculated π-π stacking interaction energies show almost same result for both DFT and ab initio methods.
文摘为探索3,4-二硝基吡唑高能熔铸炸药中分子…阳离子和阳离子…σ相互作用之间的关系,本论文借助M062X方法,在6-311++G(2d,p)基组水平上研究了Na^+…3,4-二硝基吡唑…H_2O三聚体协同效应,对其进行了分子间相互作用能和协同效应的计算与分析,然后建立了分子间距离R(R_(ternary)-R_(binary))与~2ρ(▽~2ρBCP_(ternary)-▽~2ρBCP_(binary))的线性关系。结果表明,线状三聚体结构中发生了协同效应,而在环状结构中出现了反协同效应。分子间距离R(R_(ternary-)R_(binary))与~2ρ(▽~2ρBCP_(ternary)-▽~2ρBCP_(binary))具有良好的线性关系(R^2=0.992)。AIM(atoms in molecules)与电子云密度转移分析佐证了协同效应的存在。
