COPPER(II) PROPIONATES - CRYSTAL AND MOLECULAR-STRUCTURE OF BIS(PROPIONATO)COPPER(II) DI(METHYL-3-PYRIDYLCARBAMATE)

New copper(ll) propionate compounds of composition Cu(prop)(2)L (L = m ethyl-3-pyridylcarbamate or N,N-diethylnikotinamide) and au(prop)(2)L- 2 (L = methyl-3-pyridylcarbamate or 2,6-pyridinemethanole) have been p repared. The crystal and molecular structure of the tetrakis (mu-propi onato) di(methyl-3-pyridinecarbamate) dicopper(II),Cu,(prop),(mpc),, w as determined by direct method and Fourier techniques. The compound cr ystallizes in the orthorhombic space group Pcab with four dimeric unit s in a cell with dimensions a = 19.350(4), b = 15.390(3), c = 10.725(2 )Angstrom. The structure was refined by full-matrix least-squares meth ods to a R factor of 0.031, based on 3666 independent reflections. The compound is dimeric, with square-pyramidal geometry at each copper ce ntre. The two copper atoms are bridged by four carboxylate groups, whi le the apical ligands are methyl-3-pyridylcarbamate. The structural da ta are compared with those found in similar copper(II) propionates, Sp ectral data of Cu(prop)(2)L are typical for dimeric copper(II) compoun ds. Both Cu(prop)(2)L-2 compounds seem to possess octahedral copper(II ) stereochemistry with differing tetragonal distortion.