The quantum research on the aromaticity of polycyclic aromatic hydrocarbons
Molecular aromaticity and the loss of conjugation in the polycyclic aromatic hydrocarbons (PAHs) are investigated using the restricted Hartree Fock (RHF) and Multi Reference Configuration Interaction (MRCI) method based on the average two-center indices (ATI) obtained from the electron delocalization.All the calculations were performed with the Gaussian 03 and Molpro2010 packages of programs.It is shown that the ATI values for the symmetry-unique rings decreasing from outer to inner rings both in cata-condensed and peri-condensed PAHs in the ground states.The behavior of the aromaticity indices when going from the ground state to a low-lying excited state is also examined.The ATI values of symmetry-unique rings indicate a decreasing aromaticity going from the ground states to the excited states for cata-condensed PAHs, while it has a significant increase for some symmetry-unique rings of peri-condensed PAHs.In addition, it also can be found that the ATI value of benzene aromaticity will be close to zero, when it is in the superimposed state which composed of the ground state, the third and fourth excited states.It means that in this state,benzene molecule is loss of its conjugate.The work aims at revealing the deepening loss-conjugation reasons and providing the theory basis for the research on problems of the nonaromatic superimposed state for the PAHs.
polycyclic aromatic hydrocarbons the ground state the excited state aromaticity loss of conjugation
Qingzhen Han Jinling Zhao Zhaotan Jiang Hao Wen
State Key laboratory of Multiphase Complex System,Institute of Process Engineering,Chinese Academy o School of Physics,Beijing Institute of Technology,Beijing,China,100081
国内会议
苏州
英文
735-744
2014-10-26（万方平台首次上网日期，不代表论文的发表时间）