A refinement of the crystal structure of tetraphenyl-lead

Abstract

The crystal structure of the tetraphenyl-lead has been refined by X-ray analysis. Four parameters defining the position of one phenyl ring in the cell (molecular symmetry) have been systematically varied to the minimum value of the R factor. The Pb atom has tetrahedral valence angles and the plane of each phenyl ring is rotated by about 30° about the Pb{} bond, whose length is 2.19±0.03Å. In this conformation each phenyl ring is perpendicular to the phenyl ring related to it by a diad axis, and makes an angle of about 60° to both the other two rings, thus being coplanar with the Pb{} bond of one of them. This molecular conformation is compared with that of tetra-phenyl derivatives of C, Si, Ge and Sn.