Synthesis and structure of {mu-oxalato-bis[ethylenediaminetetraacetato-bismuthato(III)]}pentaamminethiocyanatocobalt(III) dodecahydrate, [Co(NH3)(5)NCS](2)[(Edta)Bi(mu-C2O4)Bi(Edta)]center dot 12H(2)O

A heterometallic complex of cobalt(III) and bismuth(III), [Co(NH3)(5)NCs](2 )[(Edta)Bi(mu -C2O4)Bi(Edta)] . 12H(2)O, was synthesized and studied by X-r ay diffraction analysis. The crystals are monoclinic, a = 12.792(3) Angstro m, b = 9.792(2) Angstrom, c = 22.945(5) Angstrom, beta = 92.92(3)degrees, r ho (calcd) = 1.970 g/cm(3), space group P2(1)/c, Z = 4. The complex has an isle structure composed of [(Edta)Bi(mu -C2O4)Bi(Edta)](4-). and [Co(NH3)(5 )NCS](2+) complex ions and molecules of crystallization water. The Edta(4-) ligand functions as a hexadentate chelating (2N + 4O) agent, while the oxa late ion acts as a bridging ligand. The thiocyanate ion is coordinated to c obalt(III) through the N atom, while the cation interacts with the anion vi a the Bi-S contact (3.571 Angstrom). Hence, the coordination polyhedron of Bi can be regarded as a tricapped trigonal prism. It was shown that thermol ysis of the complex proceeds in several stages, viz., the deaquation, deami nation, and pyrolysis of its ligands.