A 3D pillared-layer porous framework with rare magnetic corner-sharing ∆-chain and unprecedented pentadentate 5-(4-pyridyl)tetrazolate ligand

A 3D pillared-layer porous framework, {[Co2(H2O)(μ3-OH)(ptz)(nip)]·2H2O}n (1) (ptz = 5-(4-pyridyl)tetrazolate, nip = 5-nitroisophthalate), was in situ hydrothermally synthesized and structurally and magnetically characterized. Interestingly, the layered substructure of 1 consists of scarcely observed corner-sharing Co2(μ3-OH) ∆-chain and unprecedented pentadentate ptz ligand. More importantly, due to the mixed triple syn,syn-carboxylate-μ3-OH-μ4-tetrazolyl bridges as well as the triangular CoII arrangement, 1 behaves as a typical antiferromagnetically coupled paramagnet with a slight spin frustration, which exhibits a low-dimensional antiferromagnetic ordering below 10 K (Neel Temperature).