SYNTHESIS AND CHARACTERIZATION OF TRANS-[RHCL2(OH2)(C6H3-2,6-(CH(2)PCY(2))(2))] - FACTORS INFLUENCING THE RH-O BOND-LENGTH IN RHODIUM AQUA COMPLEXES

The reaction between C6H4-1,3-(CH(2)PCy(2))(2), Cy = cyclohexyl, and R hCl3 . 3SH(2)O produced trans-[RhCl2(OH2){C6H3-2,6-(CH(2)PCy(2))(2)}], [RhCl2(OH2)(PCP)]. The product was characterised spectroscopically an d the crystal and molecular structure of its 2-propanol solvate, [RhCl 2(OH2)(PCP)]. propan-2-ol, C35H61Cl2O2P2Rh, was determined by X-ray an alysis. The crystals are monoclinic, space group P2(1)/a, with a = 11. 513(1), b = 25.874(2), c = 13.576(1) Angstrom, beta = 113.47(6)degrees , V = 3709.7(2) Angstrom(3), M = 749.71, Z = 4. Comparisons with other rhodium-aqua complexes show that the Rh-O distances are extremely sen sitive to trans influence, but insensitive to other factors such as th e oxidation state or coordination number of the metal ion, or steric c rowding. The charge on the complexes appears to exert only a minor inf luence.