The crystal structure of SnP 3 and a note on the crystal structure of GeP 3

Abstract

SnP 3 crystallizes in the trigonal space group R 3m with six formula units in a unit cell of dimensions a = 7.378Å and c = 10.512Å. The detailed atomic arrangement has been determined from three-dimensional single crystal X ray data. The structure is characterized as a layer structure related to the As-type structure (A7). The identical layers consist of puckered P 6 rings connected by Sn atoms. The centers of the P 6 rings are situated between Sn atoms of adjacent layers. This leads to a distorted octahedral coordination for the tin atoms with three phosphorus atoms belonging to the same layer as the tin atom at a distance of 2.662 Å, and three phosphorus atoms in an adjacent layer at a distance of 2.925 Å. The PP bond length within the rings is 2.222 Å and the PPP bond angle is 99.1°.