Crystal structure of complexes of bivalent Co, Ni, and Cd with anions of benzoic and 2-(acetylamino)-5-nitrobenzoic acids

The structure of three complexes of bivalent metals (cobalt, nickel, and cadmium) with anions of benzoic (H L 1 ) and 2-(acetylamino)-5-nitrobenzoic (H L 2 ) acids, namely, [Co 2 1 (H 2 O) 2 (μ-C 4 H 4 N 2 )] n ( I ), [NiL 2 (H 2 O) 5 ]L 2 · 2H 2 O ( II ), and [Cd(μ- L 2 ) 2 (H 2 O) 2 ] n · 2 n H 2 O ( III ), is determined. In chainlike structure I , cobalt atoms are connected by bridging pyrazine molecules; structure II contains isolated complexes. In structure III , centrosymmetric (CdOCO) 2 cycles and polymeric ribbons are formed due to the coordination of the carboxylate group of the L 2 ligand to two cadmium atoms.