Charge distributions in molecules and ions: mindo 3 calculations. an alternative of the charge localisation concept in mass spectrometry

Abstract

The charge distributions in a series of molecules A and their ions A + and A 2+ and in a second series B and their ions BH + and BH 2+ are presented. It is shown that their distributions are consistent with the conventional concepts of electronegativity, but not with those of the intermediate ion structures in the charge localisation concept of fragmentation processes in mass spectrometry. The charge distributions show that the carbon adjacent to a heteroatom has a considerable positive charge which apparently makes its bond to the next carbon atom weak and prone to fission which is a dominant process in the fragmentation of the positive ion.