Molecular structure and stereoisomerization of bis(2-dimethylchlorostannylethyl)phenylphosphine oxide

Abstract

NMR data ( 1H, 13C, 119Sn, 31P) have revealed that in donor-free solvents bis(2-dimethylchlorostannylethyl)phenylphosphine oxide ( 1) has a symmetric bicyclic structure with the two tin atoms intramolecularly coordinated to the PO group. In the presence of pyridine one intramolecular PO → Sn coordination is broken and the fifth coordination site of the corresponding tin atom occupied by a solvent molecule. In both solvents compound 1 undergoes various ligand exchange processes. The crystal structure of compound 1 has been determined by X-ray analysis and refined to a final R value of 0.047. The compound crystallizes in the monoclinic space group P2 1/ c. The structure consists of monocyclic units involving an intramolecular PO → Sn coordination which are associated through intermolecular SnCl … Sn bridges to give infinite zigzag chains parallel to the b-axis. The ligand polyhedra of the two tin atoms exhibit trigonal-bipyramidal geometry, with different deviations from the ideal trigonal-bipyramidal arrangement.