CRYSTAL AND MOLECULAR-STRUCTURES OF 3 [RH2(O(E)CR)4(C5H5N)2] COMPOUNDS (E = S, R = CME3, PH, E = O, R = PH)

The structures of two rhodium(II)tetramonothiocarboxylate compounds have been determined by single crystal X-ray diffraction. Only two previous studies on the structures of closely related compounds of this type have appeared in the literature. In each compound [Rh2(OSCR)4(C5H5N)2] (R = CMe3 (1), Ph (2)) the [Rh2(OSCR)4] core is centrosymmetric with each metal ion coordinated by two oxygen and two sulfur donor atoms. The two Rh-Rh bond lengths, 2.514(1) angstrom (1) and 2.521(1) angstrom (2), are appreciably greater than those observed in compounds with a [Rh2(O2CR)4] core. The structure of the tetracarboxylate compound, [Rh2(O2CPh)4(C5H5N)2] (3), has also been determined in order that detailed comparisons can be made between strictly analogous carboxylate and thiocarboxylate compounds. Crystallographic data: 1: space group C2/c, a = 19.579(9), b = 10.326(3), c = 18.156(9) angstrom, beta = 90.32(4)-degrees, V = 3671 angstrom 3, Z = 4, R = 0.0566; 2: space group P2(1)/n, a = 10.816(3), b = 14.873(4), c = 11.534(3) angstrom, beta = 104.23(3)-degrees, V = 1798 angstrom 3, Z = 2, R = 0.0602; 3: space group P2(1)/n, a = 10.049(3), b = 10.441(2), c = 17.356(4) angstrom, beta = 99.12(2)-degrees, V = 1798 angstrom 3, Z = 2, R = 0.0431.