A new six-coordinate organotin(IV) complex of OP[NC5H10]3: A comparison with an analogous five-coordinate complex by means of X-ray crystallography, Hirshfeld surface analysis and DFT calculations

Abstract

A new six-coordinate organotin(IV)-phosphoric triamide complex of OP[NC5H10]3 = OP was synthesized ([Cl2Sn(CH3)2(OP)2], 1) and characterized by X-ray crystallography and spectroscopic methods (FT-IR, UV–Vis, and 1H/13C/31P-NMR). The crystal structures of 1 and the analogous previously reported five-coordinate complex [Cl2Sn(CH3)2(OP)] (IZOVIE) were compared on a structural level and by computational means using Hirshfeld surface analysis, density functional theory calculations and the atom in molecule method. The investigation of intermolecular interactions in the crystal structures of the two complexes by the Hirshfeld surface method indicates that in the absence of normal hydrogen bonds, the chlorine-based interactions H⋯Cl/Cl⋯H (for 1 and IZOVIE) and Cl⋯Sn/Sn⋯Cl (for IZOVIE) play a determinant role in the molecular assemblies. However, the prominent contacts are of H⋯H type. From calculated electronic parameters such as bond order, Mulliken charge and electron delocalization energy, it was found that the Sn-OP contact has a lower strength in IZOVIE than in 1, suggesting more ionic character of the metal-oxygen contact in five-coordinate complex IZOVIE. Furthermore, we discuss the similarities and differences of the two complexes 1 and IZOVIE derived from the same ligand OP by density functional theory calculations to present an insight into the organotin(IV)-phosphoric triamide coordination chemistry affected by different geometries and coordination numbers.