Crystal structures and Hirshfeld surface analysis of transition-metal complexes of 1,3-azolecarboxylic acids

Abstract

The crystal structures of five new transition-metal complexes synthesized using thiazole-2-carboxylic acid (2-Htza), imidazole-2-carboxylic acid (2-H 2 ima) or 1,3-oxazole-4-carboxylic acid (4-Hoxa), namely diaquabis(thiazole-2-carboxylato-κ 2 N , O )cobalt(II), [Co(C 4 H 2 NO 2 S) 2 (H 2 O) 2 ], 1 , diaquabis(thiazole-2-carboxylato-κ 2 N , O )nickel(II), [Ni(C 4 H 2 NO 2 S) 2 (H 2 O) 2 ], 2 , diaquabis(thiazole-2-carboxylato-κ 2 N , O )cadmium(II), [Cd(C 4 H 2 NO 2 S) 2 (H 2 O) 2 ], 3 , diaquabis(1 H -imidazole-2-carboxylato-κ 2 N 3 , O )cobalt(II), [Co(C 4 H 2 N 2 O 2 ) 2 (H 2 O) 2 ], 4 , and diaquabis(1,3-oxazole-4-carboxylato-κ 2 N , O 4 )cobalt(II), [Co(C 4 H 2 NO 3 ) 2 (H 2 O) 2 ], 5 , are reported. The influence of the nature of the heteroatom and the position of the carboxyl group in relation to the heteroatom on the self-assembly process are discussed based upon Hirshfeld surface analysis and used to explain the observed differences in the single-crystal structures and the supramolecular frameworks and topologies of complexes 1 – 5 .