Structure and magnetic properties of a copper(II) coordination polymer based on azide, pyridine and homophthalic acid

The azide anion is a short bridging ligand that has been used extensively to construct magnetic coordination polymers, and fundamental magneto-structural correlations have been substantiated by theoretical calculations. The copper(II) coordination polymer poly[bis(μ-azido-κ(2)N(1):N(1))(μ4-homophthalato-κ(4)O:O':O'':O''')bis(pyridine-κN)dicopper(II)], [Cu2(C9H6O4)(N3)2(C5H5N)2]n, was synthesized from homophthalic acid (2-carboxyphenylacetic acid), pyridine and azide (N3(-)) by a hydrothermal reaction. Single-crystal structure analysis indicated that it features a one-dimensional chain structure which is comprised of (μ1,1-N3(-))(μ-syn-syn-COO(-))2- and (μ1,1-N3(-))2-bridged tetranuclear Cu(II) units. Magnetic measurements revealed that the compound exhibits dominant antiferromagnetic behaviour.