Novel organotin(IV) complexes of organophosphorus ligands: Synthesis, spectroscopic, structural study and DFT calculations

Three new phosphoric triamides with general formula C6H5C(O)NHP(O)X2, where X = N-4-phenylpiperazinyl (1), N-4-ethoxycarbonyl piperazinyl (2), and N-4-ethoxycarbonyl piperidinyl (3) as well as seven novel organotin(IV) complexes with formula SnClR1R2R3L2 where R = alkyl/aryl/Cl and L = organophosphorus ligand, were synthesized and characterized by 1H, 13C, 31P NMR, IR spectroscopy and elemental analysis. The 31P{1H} NMR spectra of compounds 9 and 10 each reveal two close signals that are related to their cis and trans isomers. DFT calculations were performed at B3LYP and M06 methods with LanL2DZ basis set using Gaussian 09 software on the cis and trans configurations of compounds 9 and 10. The structure of compound 1 was determined by X-ray crystallography. In this structure, there are two symmetrically independent molecules (1 and 1A) produced due to the co-crystallization of water and CH3OH molecules. The Pdouble bond; length as m-dashO and Cdouble bond; length as m-dashO bonds in both molecules 1 and 1A indicate an anti conformation relative to each other. The strong intermolecular N–H⋯Odouble bond; length as m-dashP hydrogen bonds plus weak intermolecular C–H⋯O(1W), C–H⋯Odouble bond; length as m-dashC, C–H⋯Odouble bond; length as m-dashP and C–H⋯N hydrogen bonds create a three-dimensional polymeric chain in the crystalline network.