COPPER(II)-MU-ACETYLENEDICARBOXYLATO-O-O'-MU-AQUA] AND IMIDAZOLE-N-3)COPPER(II)-MU-AQUA-MU-FUMARATO-O-O']

The title compounds, opper(II)-mu-acetylenedicarboxylato-O:O'-mu-aqua] , [Cu(C4O4)(C7H6N2)(2)(H2O)], (I), and midazole-N-3)copper(II)-mu-aqua -mu-fumarato-O:O'], [Cu(C4H2O4)(C7H6N2)(2)(H2O)], (II), have been synt hesized and their crystal structures determined by single-crystal X-ra y diffraction at room temperature. Structures (I) and (II) are very si milar. In both structures, the centrosymmetric Cu atoms are bridged by the dicarboxylic acid ions in a bis-monodentate fashion, forming poly meric chains. The Cu ... Cu intrachain distances are 9.546(1) Angstrom in (I) and 9.276(1) Angstrom in (II). These chains are connected by b ridging H2O molecules, which are located on the twofold axes by Cu-H2O bonds of 2.593 (1) Angstrom in (I) and 2.668(1) Angstrom in (II). The Cu ... Cu distances in the -Cu-H2O-Cu- chains are 5.090(1) and 5.199 (1) Angstrom in (I) and (II), respectively. The base of the elongated octahedron of the Cu-II atoms is formed by two short Cu-O and two shor t Cu-N bonds [Cu-O = 1.970(1) and 1.946(2) Angstrom, and Cu-N = 2.005 (2) and 2.016 (2) Angstrom in (I) and (II), respectively]. The coordin ation of the carboxylate groups and the hydrogen bonds are discussed. The isostructurality of the title compounds and of their previously in vestigated homologue, (III), has been analysed.