Crystal and molecular structure of tetraphenylcyclotetraphosphine monosulphide

Abstract

Crystals of [C₆H₅P]₄S are orthorhombic, a= 24·700(6), b= 13·508(3), c= 13·410(2)Å, Z= 8, space group Pbca. The structure was solved from diffractometer data by direct methods, and refined by full-matrix least-squares methods to R 0·083 for 1475 observed reflexions. The phosphorus and sulphur atoms form a five-membered ring which has a puckered conformation, with the sulphur atom nearly in the mean plane through the ring atoms and the phosphorus atoms alternately above and below it. Mean bond lengths are: P–P 2·190(5), P–S 2·116(5), P–C 1·831 (22), and C–C 1·382(16)Å. The angle at sulphur is 110·4(2)° and the endocyclic angles at phosphorus range from 104·2(2)–105·9(2)°, mean 105·2°. The phenyl rings are nearly perpendicular to the mean plane through the five-membered P₄S ring. Pairs of phenyl rings on the same side of the P₄S ring are close to being parallel to each other and perpendicular to the pair on the other side.