Construction and photoluminescence properties of a three‐dimensional Zn II coordination network based on naphthalene‐1,4‐dicarboxylic acid and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene

In recent years, coordination polymers constructed from multidentate carboxylate and pyridyl ligands have attracted much attention because these ligands can adopt a rich variety of coordination modes and thus lead to the formation of crystalline products with intriguing structures and interesting properties. A new coordination polymer, namely poly[[μ 2 ‐1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene‐κ 2 N : N ′](μ 3 ‐naphthalene‐1,4‐dicarboxylato‐κ 4 O 1 , O 1′ : O 4 : O 4′ )zinc(II)], [Zn(C 12 H 6 O 4 )(C 16 H 14 N 2 )] n , has been prepared by the self‐assembly of Zn(NO 3 ) 2 ·6H 2 O, naphthalene‐1,4‐dicarboxylic acid (1,4‐H 2 ndc) and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene (3,3′‐bphte) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. Each Zn II ion is six‐coordinated by four O atoms from three 1,4‐ndc 2− ligands and by two N atoms from two 3,3′‐bphte ligands, forming a distorted octahedral ZnO 4 N 2 coordination geometry. Pairs of Zn II ions are linked by 1,4‐ndc 2− ligands, leading to the formation of a two‐dimensional square lattice ( sql ) layer extending in the ab plane. In the crystal, adjacent layers are further connected by 3,3′‐bphte bridges, generating a three‐dimensional architecture. From a topological viewpoint, if each dinuclear zinc unit is considered as a 6‐connected node and the 1,4‐ndc 2− and 3,3′‐bphte ligands are regarded as linkers, the structure can be simplified as a unique three‐dimensional 6‐connected framework with the point symbol 4 4 6 10 8. The thermal stability and solid‐state photoluminescence properties have also been investigated.