Chemical structure and reactivity by means of quantum chemical topology analysis

Chemical structure and bonding are key features and concepts in chemical systems which are used in deriving structure–property relationships, and hence in predicting physical and chemical properties of compounds. Even though the contemporary high standards in determination, using both theoretical methods and experimental techniques, questions of chemical bonds as well as their evolution along a reaction pathway are still highly controversial. This paper presents a working methodology to determine the structure and chemical reactivity based on the quantum chemical topology analysis. QTAIM and ELF frameworks, based on the topological analysis of the electron density and the electron localization function, respectively, have been used. We have selected two examples studied by the present approach, to show its potential: (i) QTAIM study on the α-Ag2WO4, for the simulation of Ag nucleation and formation on α-Ag2WO4 provoked in this crystal by the electron-beam irradiation. (ii) An ELF and Thom’s catastrophe theory study for the reaction pathway associated with the decomposition of stable planar hypercoordinate carbon species, CN3Mg3+.