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-κ2N1:N1)(μ4-homophthalato-κ4O: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 CuIIunits. Magnetic measurements revealed that the compound exhibits dominant antiferromagnetic behaviour.