Bis(imidazole) coordination polymers controlled by oxalate as an auxiliary ligand

<div><p>Seven coordination polymers {[M(L)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]·(NO<sub>3</sub>)<sub>2</sub>}<sub>n</sub> (M = Co (<b>1</b>), Ni (<b>2</b>), Cd (<b>3</b>)) and [M(L)(ox)]<sub>n</sub> (M = Co (<b>4</b>), Ni (<b>5</b>), Zn (<b>6</b>), and Mn (<b>7</b>)) have been synthesized (L = 2,6-bis(imidazol-1-yl)pyridine, ox = oxalate) under hydrothermal conditions. Single-crystal X-ray diffraction analysis has revealed that <b>1–3</b> are isomorphous and possess 2-D networks, whereas <b>4–6</b> are isomorphous, but involve two kinds of oxalate chains. The structure of <b>7</b> is different from those of <b>4–6</b> due to various bridging modes of the oxalate ligand. Magnetic studies have revealed that <b>1</b>, <b>2</b>, <b>4</b>, <b>5</b>, and <b>7</b> exhibit strong antiferromagnetic coupling. Among these, <b>1</b> exhibits an interesting spin-canting phenomenon.</p></div>