A density functional theory insight into the structure and reactivity of diphenyltin(IV) derivative of glycylphenylalanine

Abstract

Abstract The quantum-chemical calculations based on density functional theory (DFT) have been performed on the diphenyltin(IV) derivative of glycyl-phenylalanine (H2L) at the B3LYP/6-31G(d,p)/LANL2DZ(Sn) level of theory without any symmetry constraint. The harmonic vibrational frequencies were computed at the same level of theory to find the true potential energy surface minima. The various geometrical and thermochemical parameters for the studied complex are obtained in the gas phase. The atomic charges at all the atoms were calculated using the Mulliken population analysis, the Hirshfeld population analysis, and the natural population analysis. The charge distribution within the studied complex is explained on the basis of molecular electrostatic potential maps, frontier molecular orbital analysis, and conceptual DFT-based reactivity (global and local) descriptors, using the finite difference approximation method. The nature of O-Sn, N-Sn, N→Sn, and C-Sn bonds is discussed in terms of the conceptual DFT-based reactivity descriptors. The structural analysis of the studied complex has been conducted in terms of the selected bond lengths and bond angles. The structural and the atomic charge analyses suggest a distorted trigonal bipyramidal arrangement consisting of negatively charged centers around the positively charged central Sn atom.