Synthesis, structures of novel zinc and copper compounds based on pyridazino[3,2-c]1,2,4-triazole derivatives

Ligands 6-phenyl-3-(4′-pyridinyl) pyridazino[3,2-c]1,2,4-triazole (L1), 6-phenyl-3-(3′-pyridinyl) pyridazino[3,2-c]1,2,4-triazole (L2) and 3,6-diphenyl pyridazino[3,2-c]1,2,4-triazole (L3) have been designed and synthesized. Reactions of these ligands with CuII, CuI and ZnII, five new metal–organic coordination complexes were obtained. X-ray diffraction analyses show that complexes 1, 3 and 4 are mononuclear structure, 5 is trinuclear complex, while 2 possess 1D chain structure. Complexes 1, 3, 4 and 5 were further assembled into infinite 1D structure by weak interactions, while 2 possesses noticeable weak interaction between two CuI atoms bridged by iodine [CuI⋯CuI = 2.6616(13) Å] and was extended into 2D sheet by π⋯π stacking interaction between adjacent chains. In addition, the steric hindrances of substituent probably weaken the coordination abilities of the pyridazine or triazole N donors.