Two new 2D coordination polymers constructed from 2, 6-dimethylpyridine-3, 5-dicarboxylic acid ligands and alkaline earth metals (Sr and Ba)

Two new alkaline earth metals coordination polymers, namely, [Sr(C9NO4H7)(H2O)2] 1 and [Ba(C9NO4H7)(H2O)2] 2 have been constructed under solvothermal conditions, employing 2, 6-dimethylpyridine-3, 5-dicarboxylic acid (H2MPDC) as organic ligand. Both the two compounds have been characterized by thermogravimetric analysis, IR spectroscopy, elemental analysis and single-crystal X-ray diffraction analyses. The results of crystal structural analysis indicate that compound 1 shows infinite chains which extend into two-dimensional (2D) sheets by μ4-MPDC2 −. Compound 2 is also a 2D layer structure and in the intralayer regions parallel left- and right-handed helical chains exist. In addition, compounds 1 and 2 exhibit strong phosphorescent emissions in the solid state at room temperature.