Cu(II) and Zn(II)-Pyridine-2,3-Dicarboxylate Complexes with 2-Methylimidazole: Syntheses, Crystal Structures, Spectroscopic and Thermal Analyses

Two new Cu(II) and Zn(II)-pyridine-2,3-dicarboxylate (pydc) complexes with 2-methylimidazole (2-Meim), [Cu(pydc)(2-Meim)(3)]center dot H2O (1) and {[Zn(mu-pydc)(H2O)(2-Meim)]center dot H2O}(n) (2) have been synthesized and characterized by elemental, spectral (IR and UV-Vis.) and thermal analyses. The molecular structures of mononuclear (1) and polynuclear (2) complexes have been determined by the single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic P - 1 space group, while compound 2 crystallizes in the monoclinic P2(1)/c space group. The pyridine-2,3-dicarboxylate ligand acts in two different coordination modes; namely, bidentate-(N,O) for 1 and mu-tridentate-(N,O,O) for 2, the latter displaying a 1D polynuclear structure. The crystal packing of the complexes exhibit 3D supramolecular frameworks including channels by C-H center dot center dot center dot pi, pi center dot center dot center dot pi, and N-H center dot center dot center dot O interactions. Water molecules occupy the channels by O-H center dot center dot center dot O hydrogen bonds.