Crystal structure of 1,4-diselenocyanatobenzene: the co-ordination of selenium(II)

Abstract

The crystal structure of 1,4-diselenocyanatobenzene has been determined by single-crystal X-ray diffraction, and refined by least-squares methods to R= 11·4%. The crystals are monoclinic, space group P2₁/c, with two centrosymmetric molecules in a cell of dimensions a= 9·12, b= 4·12, c= 11·84 Å, β= 95·7°. The C–Se–C bond angle is 94·4° and each selenium atom makes intermolecular contacts, Se ⋯ N, of 3·08 and 3·27 Å, which are appreciably less than the sum of the van der Waals radii. Each of these weak intermolecular bonds is nearly co-linear with a C–Se bond, giving approximately square-planar co-ordination around the selenium atom.

A refinement of the structure of selenium diselenocyanate by use of the published data shows that in this compound also both kinds of selenium atom show approximately square-planar co-ordination, closely similar to that found in the title compound, and resembling that already established for tellurium(II).