THE CRYSTAL AND MOLECULAR-STRUCTURE OF TRICYCLOHEXYLPHOSPHINE(TRIMETHYLSILYL)BORANE CY(3)P-CENTER-DOT-BH(2)SIME(3)

The crystal and molecular structures of the title compound have been d etermined by a single crystal X-ray diffraction study. This compound i s one of the rare species with a discrete silicon-boron two-centre/two -electron bond involving tetra-coordinate boron. The B-P bond length, 1.913(4) Angstrom, is therefore an important reference value. The conf ormations at the phosphorus, boron and silicon atoms can be described as fully staggered. The valence angle P-B-Si, 122.1(2)degrees, is rath er large, indicating the presence of steric interactions between the b ulky Me(3)Si and Cy(3)P groups.