SYNTHESES AND CRYSTAL-STRUCTURES OF CO-3(C2O4)(SEO3)(2) AND ZN(C2O4)CENTER-DOT-2H(2)O

Co-3(C2O4)(SeO3)(2) and Zn(C2O4) . 2 H2O were synthesized investigatin g the reaction products of Fe(C2O4) . 2 H2O and SeO2 combined with tra nsition metal elements at low-hydrothermal conditions. The crystal str uctures were determined by direct methods from single-crystal X-ray di ffraction data. CO3(C2O4)(SeO3)(2): space group C2/m, Z=2, a = 9.163(2 ) Angstrom, b = 6.513(2) Angstrom, c = 7.806(2) Angstrom, beta = 117.1 4(2)degrees, V = 414.6(2) Angstrom(3), R1 = 0.023. Zn(C2O4) . 2 H2O: s pace group C2/c, Z=4, a = 11.812(3) Angstrom, b = 5.402(1) Angstrom, c = 9.919(2) Angstrom, beta = 127.72(1)degrees, V = 500.6(1) Angstrom(3 ); R1 = 0.029. Both compounds consist of MO6 octahedra (M = Co, Zn), l inked via the oxalate groups to chainlike subunits. These are further combined via additional CoO6 octahedra and the trigonal pyramidal sele nite group or via hydrogen bonds, respectively. Mean bond lengths are 2.119 Angstrom and 2.099 Angstrom for Co-[6]-O, 1.701 Angstrom, for Se (IV)([3])-O and 2.094 Angstrom for Zn-[6]-O.