Coordination polymers constructed from a tripodal phosphoryl carboxylate ligand: synthesis, structures and physical properties

Abstract

By employment of a new tripodal phosphoryl carboxylate ligand, tris(p-carboxyl-biphenyl)phosphine oxide (H₃TBPPO), four novel coordination polymers, namely, Zn₃(TBPPO)₂ (1), Cd₃(TBPPO)₂ (2), Co₃(TBPPO)₂ (3) and In(TBPPO) (4), have been synthesized and characterized. Complexes 1, 2 and 3 are isostructural. Crystal structure analysis reveals that complexes 1–3 consist of trinuclear metal building units, which are further bridged by the tripodal phosphine oxide carboxylate ligands to give a (4,8)-connected 2-fold interpenetrating flu topological net with a point symbol of (4¹²·6¹²·8⁴)(4⁶)², while complex 4 possesses a 3D 4-fold interpenetrating dia network with a point symbol of (6⁶). Luminescence measurements indicate that complexes 1, 2 and 4 all show strong emission bands at around 378 nm in the solid state at room temperature. Furthermore, temperature-dependent magnetic susceptibility study shows that complex 3 exhibits antiferromagnetism properties.