Cobalt and cadmium complexes with N-heterocyclic dicarboxylic acid ligands: Syntheses, structures, magnetic and fluorescent properties

Abstract Two new complexes, [Co(Himdc) 2 (H 2 O) 2 ] ( 1 ) and {[Cd(pzdc)(H 2 O)]·H 2 O} n ( 2 ) (H 2 imdc = imidazole-4, 5-dicarboxylic acid, H 2 pzdc = pyrazine-2, 3-dicarboxylic acid), have been synthesized and structurally characterized. Compound 1 is a new triclinic mononuclear complex formed by two Himdc − ligands trans coordinated to the Co II center in bidentate chelate mode and two water ligands. Compound 2 shows a two dimensional layer structure in which pzdc 2− dianion ligand adopts unique doubly bridging bis-bidentate μ 4 coordination mode. Temperature-dependent magnetic susceptibilities and thermal stability for 1 and solid-state fluorescent properties for 2 have been discussed in detail.