A series of coordination polymers based on a 5-(3′-amine-1′H-pyrazol-4′-yl)-1H-tetrazole ligand: synthesis, structure and properties

Abstract

A new family of coordination polymers, {[Co(Hapt)₂]·2H₂O}_n (1, H₂apt = 5-(3′-amine-1′H-pyrazol-4′-yl)-1H-tetrazole), {[Zn(Hapt)₂]·3H₂O}_n (2), {[Cd(Hapt)₂]·2.5H₂O}_n (3) and [Cu(Htpa)₂]_n (4) have been prepared under hydrothermal conditions and characterized by elemental analyses and X-ray structural analyses. The tetrazole ligand adopts two coordination modes generating two kinds of 2D layers. Among them, 1–3 are isomorphous. Furthermore, extended 3D supramolecular architectures are constructed for these complexes via predictable secondary interactions such as O⋯H–C and O⋯H–N hydrogen bonding. Magnetic studies indicate that compound 1 exhibits magnetic ordering below 4.5 K with spin canting. The fluorescence studies show that the emissions of complexes 2–3 are attributed to the ligand π–π* transition.