An Atoms-in-Molecules Theory Interpretation for the Structure of Di-n-Butyltin(IV) Derivative of Glycylvaline

Abstract

The topological and energetic properties of the electron density distribution ρ\( (\vec{r}) \) for the tin–ligand interaction in n-Bu2SnL, the geometric configuration of which was optimized at B3LYP/6-31G(d,p)/LANL2DZ(Sn) level of theory, have been theoretically calculated at the bonds around the central Sn atom in terms of atoms-in-molecules (AIM) theory using AIMAll (Version 16.01.09, standard). In n-Bu2SnL, the formation of a (3, − 1) critical point in the internuclear region between tin atom and bonded/coordinated atoms provided an evidence of a bonding interatomic interaction, and calculated bond path angles indicated a distorted trigonal bipyramidal geometry. The calculated topological and energetic parameters suggested a weak closed-shell interaction in all the bonded/coordinated bonds to Sn atom. This interaction possessed covalent character in Sn–Npeptide, Sn–Cα and Sn–Cα′, whereas an electrostatic interaction was observed in Sn–Namino and Sn–Ocarboxyl bonds. The calculated atomic charges suggested negatively charged centers around the central Sn atom.