X-ray crystal structure determination of bis(triphenylbenzylphosphonium) tetrachlorocadmate dichloroethane solvate

Abstract

The molecular and crystal structure of the title compound has been determined from X-ray diffractometer data. The structure was solved by direct and Fourier methods and refined by least-squares techniques to R  0.063 for 2246 independent reflections. Crystals are monoclinic, space group P2 1/ c, with four [CdCl 4] 2- · 2[(C 6H 5) 3PCH 2C 6H 5] + · 2 Cl 2C 2H 4 formula units in a unit-cell of dimensions a 14.73(2), b 24.88(3), c 16.37(2) Å, β 112.61(10)°. The tetrachlorocadmate(II) anion shows a quasi-perfect tetrahedral symmetry and is surrounded by two dichloroethane solvent molecules. The benzyl-triphenylphosphonium cations adopt quasi-perfect tetrahedral symmetry around the P atoms with the PC(Phen) bonds in slightly distorted staggered conformations ( gauche, gauche+, and trans) with respect to the C(Phen)CH 2 bond of the benzyl groups. The bond lengths and the angles of the ions are in excellent agreement with literature data. The parameters of the dichloroethane molecules are rather poorly defined as the crystal loses the solvent even at room temperature and atmospheric pressure. The ClC bonds of the two ClCH 2CH 2Cl molecules are nearly in the gauche conformation. The interatomic distances between the ions correspond to the usual Van del Waals distances.