在不加对称性限制的条件下采用不同的半经验方法研究酞菁的电荷分布和几何构型

在不加对称性限制的条件下采用不同的半经验方法CNDO,INDO,MINDO/3,MNDO和Pm3对自由酞菁(H₂Pc)进行几何构型最优化和电荷密度布居分析，并将所得结果与Am1方法以及X射线衍射和中子衍射数据的数据进行比较。结果表明只有从INDO方法得到的是桥式构型，而从CNDO,MINDO/3,MNDO,Am1,Pm3方法得到的都是键式构型。除INDO之外所有的这几种方法都对先前报道的几何构型扭曲给出进一步的支持证据。新近建立的半经验方法如MNDO,Am1,Pm3等看起来更适合于用

The Electron Distribution and Geometry Investigation on Phthalocyanine with Different Semi-empirical Methods without any Symmetry Constraint

Geometry optimization and electron density population analysis of free base phthalocyanine with different se-mi-empirical methods, namely CNDO, INDO, MINDO/3, MNDO and Pm3, were performed without any symmetry constraint and compared with that of Am1 method as well as the X-ray diffraction and neutron diffraction data. The optimized geometry of H₂Pc was found to be bridge-style configuration from INDO method and bond-style configu-ration from CNDO, MINDO/3, MNDO, Am1, Pm3 methods, respectively. All these methods except INDO give further evidence to support the geometry distortion as reported previously. The recently founded semi-empirical methods, say MNDO, Am1, Pm3, seem to be more suitable to investigate the distortion evidence of the geometry and the polarization of the electron distribution in the macromolecules such as phthalocyanine and its analogues.