The electrophilic aromatic substitution reactions have been studied by using the con- cept of pseudo orbital proposed by authors,Because the unoccupied orbitals of electrophilic reagents have been.taken into account,t...The electrophilic aromatic substitution reactions have been studied by using the con- cept of pseudo orbital proposed by authors,Because the unoccupied orbitals of electrophilic reagents have been.taken into account,the present results are better than ones given by superdelocalizability,S,.展开更多
The substitution effect of fluorine on ethylene is investigated by means of studying the properties of the charge distribution at the bond critical points with the theory of atoms in molecules.It is found that fluorin...The substitution effect of fluorine on ethylene is investigated by means of studying the properties of the charge distribution at the bond critical points with the theory of atoms in molecules.It is found that fluorine atom acts not only as a σ electron acceptor,but also as a π electron donor,and these double effects are reflected in the quantity of ellipticity,Lap- lacian and the charge density of charge distribution at the bond critical points.For C—C,C—F bonds,the major axis of elliptical contours is perpendicular to the molecular plane,but for C—H bond,it is parallel to the molecular plane.Other effects originating from the substi- tution have also been discussed.展开更多
For the isomerization reaction of monofluoro-disilene,the geometrical structures of reac- tant,product and transition state have been optimized and energy constant,vibrational frequency calculated.By means of the stat...For the isomerization reaction of monofluoro-disilene,the geometrical structures of reac- tant,product and transition state have been optimized and energy constant,vibrational frequency calculated.By means of the statistical thermodynamics and Eyring's transition state theory,the equilibrium constant,rate constant and heat of isomerization have also been computed.Hence, this reaction has been analysed completely.展开更多
文摘The electrophilic aromatic substitution reactions have been studied by using the con- cept of pseudo orbital proposed by authors,Because the unoccupied orbitals of electrophilic reagents have been.taken into account,the present results are better than ones given by superdelocalizability,S,.
基金Project supported by the National Natural Science Foundation of China.
文摘The substitution effect of fluorine on ethylene is investigated by means of studying the properties of the charge distribution at the bond critical points with the theory of atoms in molecules.It is found that fluorine atom acts not only as a σ electron acceptor,but also as a π electron donor,and these double effects are reflected in the quantity of ellipticity,Lap- lacian and the charge density of charge distribution at the bond critical points.For C—C,C—F bonds,the major axis of elliptical contours is perpendicular to the molecular plane,but for C—H bond,it is parallel to the molecular plane.Other effects originating from the substi- tution have also been discussed.
基金This research was supported by the National Natural Science Foundation of China.
文摘For the isomerization reaction of monofluoro-disilene,the geometrical structures of reac- tant,product and transition state have been optimized and energy constant,vibrational frequency calculated.By means of the statistical thermodynamics and Eyring's transition state theory,the equilibrium constant,rate constant and heat of isomerization have also been computed.Hence, this reaction has been analysed completely.
