Extended structures of two coordination polymers based on 1,10-phenanthroline derivatives: Preparation, structural characterization and properties

In this paper, we report two coordination polymers, [Cd(Medpq)(SO4) (H2O)2]n (1) and {[Mn(Medpq)(QUI)H2O] ⋅ H2O} n (2) (H2QUI = 2,3-pyridinedicarboxylic acid, Medpq = 2-methyldipyrido[3,2-f:2,3-h]quinoxaline) by hydrothermal processing and structural characterization by elemental analysis, thermogravimetric analysis and single-crystal X-ray diffraction. The coordination polymers 1 and 2 have 1D chains formed via coordination bonds, and unique two-dimensional supramolecular structures are further formed due to π- π stacking interactions. The results reveal that the coordination preferences of metal ions play a critical role in the framework construction of the two coordination polymers. Meanwhile, natural bond orbital (NBO) analysis was performed by the PBE0/LANL2DZ method in Gaussian 09 program. The calculated results show the obvious covalent interaction between the coordinated atoms and metal ions.