Structures, Theoretical Vibrational Frequency and 1H-NMR Spectral Analysis of Pyrazine-Dibenzylsulfoxide Platinum(II) Complexes

Abstract

Mixed-ligand Pt(II) complexes containing pyrazine (C4N2H4, pz) and dibenzyl sulfoxide [C6H5CH2)2SO, DBzSO] ligands have been studied using density functional theory (DFT) methods with a particular emphasis on the theoretical1H-NMR spectra of the methylene protons. The DFT optimization calculations on Pt(DBzSO)Cl2(pz) and {Pt(DBzSO)Cl2}2(pz) predicted the structure parameters, vibrational frequency and1H-NMR spectra. Different structures of DBzSO will affect the bond lengths and angles in the complexes, except for the pz ligands. The [shift(Pt(II)complex)-shift(sulfoxide)] values of trans-Pt(DBzSO)(pz)Cl2were smaller than those for cis-Pt(DBzSO)(pz)Cl2and the calculation results appear to be reasonable. The1H-NMR spectra of the methylene protons of cis- and trans-{Pt(DBzSO)Cl2}2(pz) indicate that these two structures have high symmetry.