中文摘要：

运用密度泛函理论方法B3LYP,选取6-31G（d,p）和6-31G（d）两种基组对C6FmH6-m（m=1～6）进行了几何优化,并对优化结构运用B3LYP/6-31G（d,p）方法进行了键能计算,选用B3LYP-GIAO/6-31＋＋G（d,p）方法进行核无关化学位移（Nucleus-Independent Chemical Shifts,NICS）的计算.研究表明,所研究的氟代苯的基态均呈平面几何结构,6-31G（d,p）基组计算的键长、键角的结果与实验值更加吻合,其芳香性都较苯的大,且随取代F数目的增加而增大.用NBO对分子总NICS及各键对NICS的贡献进行了分解,结果显示,氟的pz孤对电子参与六元环π键的形成是使氟代苯分子芳香性变大的主要原因.

英文摘要：

The geometries and bonding energies were predicted with the hybrid density functional method B3LYP.Bond distances and bond angles predicted with 6-31G（d,p） basis set are closer to the experimental values than those with 6-31G（d） basis set.The geometries of all C6FmH6-m（m=1～6） are planar.The nu-clear independent chemical shift（NICS）,calculated using B3LYP-GIAO/6-31＋＋G（d,p）,indicates that all fluorinated benzenes are more aromatic than benzene,and the aromaticity increases with the number of F in C6FmH6-m（m=1～6）.The various dissected bond NICSs reveal that the pz lone pair electrons of F atoms play a dominant role in the aromaticity of C6FmH6-m（m=1～6）,and participate in formation of π current of the hexagon.