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

Abstract

Two new alkaline earth metals coordination polymers, namely, [Sr(C 9 NO 4 H 7 )(H 2 O) 2 ] 1 and [Ba(C 9 NO 4 H 7 )(H 2 O) 2 ] 2 have been constructed under solvothermal conditions, employing 2, 6-dimethylpyridine-3, 5-dicarboxylic acid (H 2 MPDC) 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 μ 4 -MPDC 2 − . 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. Structural view of the coordination polymer [Ba(C 9 NO 4 H 7 )(H 2 O) 2 ] ( 2 ). For compound 2 , the [BaO 8 ] units are connected with μ 5 -MPDC 2 − ligands to form an interesting chiral helical chain, and the adjacent chiral helical chains are further connected by the μ 5 -MPDC 2 − bridges to form a 2-D layer. • Two compounds constructed from H 2 MPDC ligand and alkaline earth metals. • Both the two compounds are linked by 1D chains to form a 2D layer. • In compound 2 , it contains interesting chiral helical chains. • Both compound 1 and 2 exhibit strong blue photoluminescence properties.