[Co(μ‐ox)(Hpmtz)] – A New Co II Zig‐Zag Chain Complex with the In Situ Generated Oxalate Bridging and Hpmtz Chelating Ligands (Hpmtz = 5‐pyrimidyltetrazole) Exhibiting Spin‐Canted Antiferromagnetism

The compound [Co(μ‐ox)(Hpmtz)] (Hpmtz = 5‐pyrimidyltetrazole, ox = oxalate) has been synthesized under hydrothermal conditions by reacting CoCl 2 · 6H 2 O with 2‐cyanopyrimidine and sodium azide. Both ox and Hpmtz ligands were generated in situ during the hydrothermal reaction. The structure of [Co(µ‐ox)(Hpmtz)] consists of oxalate‐bridged Co II zig‐zag chains bearing Hpmtz chelating ligands. These chains form layers in the ab plane via π ··· π stacking interactions involving the pmtz ligands belonging to neighbouring chains. Layers stack along the c axis with an ABAB sequence and are glued by cooperative C9–H ··· O4 interactions leading to a 3D structure. Magnetic susceptibility measurements indicate that this compound shows spin‐canted antiferromagnetism (weak ferromagnetism) with T C = 6.5 K.