Preparation and Crystal Structure of Tetrakis(μ-pivalato-O,O′)bis[(pivalic acid-O)rhodium(II)]

The title compound, a dinuclear rhodium(II) complex with pivalic acid (Hpiv), [Rh2(piv)4(Hpiv)2], was isolated, and the crystal structure was determined by the single-crystal X-ray diffraction method at 293 K. It crystallizes in the monoclinic space group P21/c with a = 9.465(2)A, b = 18.222(5)A, c = 11.743(3)A, β = 99.450(5)°, V = 1998.0(9)A3, Dx = 1.354 g/cm3, and Z = 2. The R1 [I > 2σ(I)] and wR2 (all data) values are 0.0420 and 0.1095, respectively, for all 4413 independent reflections. The molecule is a tetrakis(μ-pivalato)-bridged dinuclear rhodium(II) complex with a Rh-Rh distance of 2.3858(7)A, having an elongated square-pyramidal coordination geometry with the O4 basal atoms from the four bridging piv- ligands and the apical O atom from the Hpiv ligand.