A novel metal-organic complex formulated as [Cd (phen)(dipic) (H2O)2]. 3 H2O (phen = 1, 10-phenanthroline; dipic2−= pyridine-2,6-dicarboxylate) has been hydrothermally synthesized at 150°C for 48h. The structure of Cd complex was characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and single-crystal X-ray diffraction (SC-XRD). The crystal system of Cd complex is monoclinic with space group C 2/c. The pentagonal bipyramid (seven coordinate) around Cd2+ center filled by two terminal water ligands, one 1,10-phenanthroline, and one pyridine-2,6-dicarboxylate anion. Extensive O–H···O hydrogen bonding interactions involving all coordinated water molecules, dipicolinate oxygens, and crystallization water molecules further stabilize the complex units by linking them to form three-dimensional polymeric networks. Indeed, quantum mechanical studies were performed to understand effective factors on stability of the Cd(II) complex.