A porous metal organic framework with a bcu-type topology involving in situ ligand formation – synthesis, structure, magnetic property and gas adsorption studies

Abstract

A three-dimensional (3D) porous metal organic framework namely, {[Cu₃(N₃)₂(4-ptz)₄(DMF)₂]·2DMF}_n, has been synthesized using Cu(CH₃COO)₂·H₂O and ligand 4-ptz [5-(4-pyridyl)-tetrazolate] which was formed in situ from 4-cyanopyridine and sodium azide in presence of water and Cu^II ions. Crystal structure analysis showed that the complex crystallizes in the monoclinic space group P2₁/c and has a decorated body centred cubic (bcu) topological net with 8-connected Cu3 cluster as node. Magnetic studies exhibit prominent antiferromagnetic interactions influenced by EO (end on) azide and μ₂,η²-tetrazolato bridge among the metal centres. Gas adsorption studies reveal moderate carbon dioxide uptake, which is also reflected in the isosteric heat of adsorption (Q_st) value of −28 kJ mol⁻¹.