SYNTHESIS AND CRYSTAL-STRUCTURE OF (RH-2(O2CCH3)(4)CENTER-DOT-P(O-CH3OC6H4)PH(2))(2) - A NOVEL DIRHODIUM(II) MONOADDUCT WITH INTERMOLECULARMU-OXO INTERACTIONS

We have investigated the reaction of dirhodium tetraacetate with the p hosphine P(o-CH3OC6H4)Ph(2) (P) under different experimental condition s. From these reactions we have been able to isolate the dirhodium tet raacetate phosphine mono-adduct. The crystal structure shows that in t he solid state this compound forms a centrosymmetric dimer of the dime r, {Rh-2(O2CCH3)(4) . P(o-CH3OC6H4)Ph(2)}(2), in which one oxygen atom from one acetate group in one Rh-2(O2CCH3)(4) . P unit is axially coo rdinating one Rh atom on another Rh-2(O2CCH3)(4) . P unit is axially c oordinating one Rh atom on another Rh-2(O2CCH3)(4) . P unit (Rh ... O 2.437(3) Angstrom intermolecular versus Rh ... O 2.043(3) Angstrom int ramolecular), and vice versa. The Rh-Rh bond distance is 2.414(1) Angs trom while the intermolecular Rh ... Rh distance is 3.455(2) Angstrom.