Synthesis, structure and fluorescence properties of a novel 3D Sr(II) coordination polymer

Solvothermal reaction of 2,2'-bipyridine-5,5'-dicarboxylic acid (H(2)bpdc) and SrCl2 affords a novel coordination polymer [Sr(Hbpdc)(2)](n) 1. X-ray structure determination shows that I exhibits a novel three-dimensional network. The unique Sr (II) cation sits on a two-fold axis and coordinated by four O-atom donors from four Hbptc(-) ligands and four N-atom donors from two Hbptc(-) ligands in distorted dodecahedral geometry. In 1 each Sr (II) cation connects to six different Hbptc(-) ligands and each Hbptc(-) ligand bridges three different Sr (II) cations which results in the formation of a three-dimensional polymeric structure. Corresponding to the free ligand, the fluorescent emission of complex 1 display remarkable "Einstain" shifts, which may be attributed to the coordination interaction of Sr atoms, thus reduce the rigidity of pyridyl rings. (C) 2016 Elsevier B.V. All rights reserved.