A theoretical study of NO2 complexes with aluminium and gallium based on topological analysis of electron density and electron localization function

Results of DFT and MP4 calculations on AlNO2 and GaNO2 molecules are presen ted. One C-s and two C-2v structures (two minima and one TS) are found and their energies and vibrational frequencies are reported and discussed. The minima are close in energy and lie ca. 70 kcal mol(-1) below reactants (M NO2). More insight is obtained via topological analysis of electron densit y and electron localization function (ELF). It is shown that the molecules are bound mainly via electrostatic interactions, and there is a significant charge transfer from metal atom to the NO2 moiety. Detailed analysis of th e ELF shows that the loss of stability of gallium complexes with respect to aluminium structures is best explained by (antibonding) influence of galli um semi-core d electrons. (C) 2000 Elsevier Science B.V. AU rights reserved .