Syntheses, characterizations and luminescence properties of four novel coordination polymers based on 4,4′-(phenylazanediyl)dibenzoic acid with two rigid N-donor imidazol ligand

Abstract

Four novel coordination polymers (CPs), namely, [ZnL(bimb)]·DMF (1), [ZnL(bimb)]·6(H2O)0.5 (2), [ZnL(bimp)0.5]·3H2O (3) and [ZnL(bimp)]·7H2O (4), (H2L=4,4′-(phenylazanediyl)dibenzoic acid, bimb=1,4-bis(imidazol-1-yl)benzene, bimp=3,5-bis(1-imidazoly)pyridine), have been synthesized under hydrothermal conditions with different solvents and decreased temperature rates. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), elemental analyses, and thermogravimetric analyses (TGA). 1 exhibits an infinite 4-fold interpenetrated three-dimensional (3D) framework with (66) topology. 2 displays the 2D undulated sheets leading to form a 3D framework with π-π interactions among layers in ABAB fashion. 3 exhibits an infinite 2-fold interpenetrated 3D framework with (412·63) topology. 4 exhibited 2D layer with {42·63·8} topology structure. Photoluminescence properties of 1–4 in solid state at ambient temperature were studied, too.