Synthesis and molecular structure of an inorganic zwitterion: trichloro{[2-(diphenylphosphinyl)ethyl]dimethylammonium}copper(II)

Abstract

The solid-state structure of the title compound has been determined by X-ray crystallographic methods (Patterson and Fourier) from both film and automated diffractometer data. Crystals are monoclinic, and diffractometer results indicate space group Cc with Z= 8, cell dimensions: a= 12·713(1), b= 12·633(1), c= 24·474(2)Å, and β= 91·05(1)°. The structure was refined to R 0·071 for 2709 independent reflections.

The results clearly show the zwitterionic nature of the complex. The co-ordination polyhedron around each copper(II) atom is a distorted tetrahedron. The co-ordination sphere is comprised of the three anionic chloride ligands and the oxygen atom of the phosphinyl group. The overall solid-state packing of the individual molecules reflects the intermolecular hydrogen bonding between the proton on the nitrogen and the chlorine atoms. As a result, the molecules form hydrogen-bonded chains which run parallel to the c axis. Important bonds and angles are: Cu–O 2·00, P–O 1·50 Å; Cu–O–P 145·5°.