Solvent effects on 2,4-dinitrotoluene（2,4-DNT） molecule in different solvents（toluene, ethanol, and water） were studied via DFT PCM method at B3LYP/6-311＋G（d,p） level. The influences of these solvents on the mo...Solvent effects on 2,4-dinitrotoluene（2,4-DNT） molecule in different solvents（toluene, ethanol, and water） were studied via DFT PCM method at B3LYP/6-311＋G（d,p） level. The influences of these solvents on the molecular structure, vibrational spectra, charge distribution, and dipole moment were studied as well. The results show that PCM computations are successful in describing the vibrational spectra of 2,4-DNT molecules in these solutions and the solvent effects on the low frequency vibrational spectra are weak.展开更多
The polarizability（α） and second hyperpolarizability（γ） were systemically investigated for singlet diradical complex involving X（X=B,Al,Ga） atom.The results show that both the α and γ can be effectively tune...The polarizability（α） and second hyperpolarizability（γ） were systemically investigated for singlet diradical complex involving X（X=B,Al,Ga） atom.The results show that both the α and γ can be effectively tuned by varying the distance R（between compound A and a water molecule） and acceptor atom X.The lone pair of electrons from the O atom of the water molecule entered into the vacant p orbital of atom X,which increased the diradical character and led to the increase of the α and γ values.Furthermore,the polarizable continuum model（PCM） was used to test the effects of H2O and CCl4 solvents on the α and γ values.Both the α and γ values of the studied diradical complex 1a（1b,1c） in H2O and CCl4 were uniformly enhanced.And the solvent effects of H2O on either α or γ were larger than those of CCl4.展开更多
The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-1-cyclohexen-1-yl trifluoromethane–sulfonate was studied with the density functional theory(DFT). The geomet...The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-1-cyclohexen-1-yl trifluoromethane–sulfonate was studied with the density functional theory(DFT). The geometries of the reactants,transition states, intermediates and products were optimized at the B3LYP/6-31+G* level. Meanwhile, the single point energy of species involved in gas and solvent at B3LYP/6-311+G* level was individually investigated. Polarizable continuum models(PCM)were applied to the dioxane and water solutions at the same level, respectively. Results show that the rate-limiting step, M3→TS3,does not change in different solutions. However, the activation energy in a dioxane solution is lower than that in water, which explains the previous experimental results. Compared with the non-catalyzed reaction process, the activation energy of the ratelimiting step is reduced by 56.53 kJ mol-1 in gas and 44.84 kJ mol 1in solvent, demonstrating a high catalytic efficiency of CuI.展开更多
基金Supported by the National Natural Science Foundation of China(No.10534010)
文摘Solvent effects on 2,4-dinitrotoluene（2,4-DNT） molecule in different solvents（toluene, ethanol, and water） were studied via DFT PCM method at B3LYP/6-311＋G（d,p） level. The influences of these solvents on the molecular structure, vibrational spectra, charge distribution, and dipole moment were studied as well. The results show that PCM computations are successful in describing the vibrational spectra of 2,4-DNT molecules in these solutions and the solvent effects on the low frequency vibrational spectra are weak.
基金Supported by the National Natural Science Foundation of China(No.20873017)the Natural Science Foundation of Jilin Province,China(No.20101154)
文摘The polarizability（α） and second hyperpolarizability（γ） were systemically investigated for singlet diradical complex involving X（X=B,Al,Ga） atom.The results show that both the α and γ can be effectively tuned by varying the distance R（between compound A and a water molecule） and acceptor atom X.The lone pair of electrons from the O atom of the water molecule entered into the vacant p orbital of atom X,which increased the diradical character and led to the increase of the α and γ values.Furthermore,the polarizable continuum model（PCM） was used to test the effects of H2O and CCl4 solvents on the α and γ values.Both the α and γ values of the studied diradical complex 1a（1b,1c） in H2O and CCl4 were uniformly enhanced.And the solvent effects of H2O on either α or γ were larger than those of CCl4.
文摘The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-1-cyclohexen-1-yl trifluoromethane–sulfonate was studied with the density functional theory(DFT). The geometries of the reactants,transition states, intermediates and products were optimized at the B3LYP/6-31+G* level. Meanwhile, the single point energy of species involved in gas and solvent at B3LYP/6-311+G* level was individually investigated. Polarizable continuum models(PCM)were applied to the dioxane and water solutions at the same level, respectively. Results show that the rate-limiting step, M3→TS3,does not change in different solutions. However, the activation energy in a dioxane solution is lower than that in water, which explains the previous experimental results. Compared with the non-catalyzed reaction process, the activation energy of the ratelimiting step is reduced by 56.53 kJ mol-1 in gas and 44.84 kJ mol 1in solvent, demonstrating a high catalytic efficiency of CuI.
