Synthesis, structural characterization and DFT calculations of a new one-dimensional diorganotin(IV) derivative of N-isonicotinyl phosphoramide

Abstract

A new diorganotin complex with formula {SnCl2(CH3)2L}n (1), L=N-isonicotinyl, N′,N″-bis(α-methylbenzyl) phosphoric triamide, was synthesized and characterized on the basis of elemental analysis, IR and multinuclear NMR spectroscopy. Solid state structure of 1 was established by single crystal X-ray diffraction, revealing a distorted octahedral geometry for Sn, with trans-(dimethyl), cis-(Cl2) and cis-(L2) configuration. Coordination of L from Ophosphoryl and Npyridine, as a bridging bidentate ligand, resulted in infinite 1D polymeric chains along b axis. Non-covalent interactions, i.e. hydrogen bonding, π–π stacking and CH⋯HC contacts further connected the chains into a 3D framework. The main intermolecular interactions were supported by Hirshfeld surface analysis and fingerprint plots. Density functional theory (DFT) calculations were performed for 1 and its possible all-trans isomer to compare their relative stability and results showed that the latter is the stable form in the gas phase. By using parameters derived from the quantum theory of atoms in molecules, the nature of Sn–ligand interaction is found to be mainly electrostatic with a small amount of covalent character. Natural bond orbital analysis showed donor–acceptor delocalizations from donor atoms to tin center.