A new cobalt coordination polymer based on Co(II)-azide chains and a tetrapyridyl ligand: Synthesis, unprecedented topology and magnetism

A new cobalt(II) coordination polymer formulated as [Co₂(N ₃)₄(L)]_n·4n H₂O (1) (L = tetrakis(3-pyridyloxymethylene) methane) was synthesized by a diffusion method, and structurally and magnetically characterized. In compound 1, the Co(II) chains with double end-to-end (EE) azide bridges are interlinked by the tetrapyridyl ligands into a three-dimensional framework. With both Co(II) and L as 4-connecting nodes, the structure represents the first real example of the 4-connected net topology with point symbol (6²·7 ⁴)(6⁴·7·9)₂. Magnetic studies demonstrated that the double EE azide bridges transmit antiferromagnetic interactions along the chain.