Cadmium–Organic Coordination Polymers Based on N-Donor Ligands and Small Anions: Syntheses, Crystal Structures, and Photoluminescent Properties

By using two types of arene core-based rigid N-containing ligands, we have solvothermally synthesized two cadmium metal–organic coordination polymers, {[Cd 6 (dpb) 6 (HCOO) 8 (H 2 O) 4 ]·4NO 3 ·4H 2 O} n ( 1 ) and {[Cd 4 (tib) 4 (H 2 O) 4 (NO 3 ) 6 ]·2NO 3 } n ( 2 ) (dpb = 1,4-bis-(4-pyridyl)-benzene, tib = 1,3,5-tris(1-imidazolyl)benzene), and characterized them. The coordinated small anions HCOO – and NO 3 – play important roles in the formation of 1 and 2 . In 1, the coordinated formate ligand from in situ hydrolysis of DMF binds metal centers to generate a rigid 2D metal–formate honeycomb layer, which is further connected by dpb ligands to generate a 3D pillar–layer complex. Complex 2 possesses a 2-fold interpenetrating 2D framework with an extremely rare (3,4) connected topology. Photochemical properties of these new complexes have been studied.