Construction of metal–organic coordination polymers derived from 4-substituted tetrazole–benzoate ligands: synthesis, structure, luminescence, and magnetic behaviors

Abstract

Using 4-substituted tetrazole–benzoate ligands, 4-aminophenyl-1H-tetrazole (HL¹) and 4-carboxyphenyl-1H-tetrazole (H₂L²), five metal–organic coordination polymers formulated as [Co₃(OH)₂(L¹)₄(H₂O)₂]_2n (1), [Zn(L¹)₂]_n (2), [Ag(L¹)]_n (3), [Co(L²)(H₂O)]_n (4) and [Pb(L²)]_n (5) have been hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction. Due to the effects of the different metal centers and the substituted groups of ligands, such as –NH₂ and –COOH, compounds 1–5 demonstrate different characteristics. Compound 1 features a 3D framework with a rare (3,6)-connected rtl (rutile) topology. Compound 2 crystallizes in a noncentrosymmetric space group Pn2 and manifests a 3D non-interpenetrated dia framework. Compound 3 shows a 2D layer structure with 3-connected 4·8²-fes topology. Compound 4 exhibits a uninodal 8-connected body-centered cubic (bcu) net with a Schläfli symbol of 4²⁴·6⁴. Compound 5 possesses a 3D framework with 5-connected 4⁶·6⁴-bnn (hexagonal boron nitride) topology. Luminescent studies show that compounds 1–5 exhibit good solvent-dependent properties, especially in their response towards acetonitrile, carbon tetrachloride and acetone molecules. In addition, compound 1 shows spin-canted antiferromagnetism at low temperature.