Syntheses, structures, and photoluminescence of a novel class of d10 metal complexes constructed from pyridine-3,4-dicarboxylic acid with different coordination architectures

Two novel d(10) metal coordination polymers [Zn(PDB)](n) (1) and [Cd-3(PDB)(2)(OH)(2)(H2O)(2)](n) (2) (H2PDB = pyridine-3,4-dicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG analysis, and single-crystal X-ray diffraction. Crystal data for 1: C7H3NO4Zn, orthorhombic Pna2(1), a = 8.423(17) Angstrom, b = 6.574(13) Angstrom, c = 12.899(3) Angstrom, Z = 4. Crystal data for 2: C14H12N2O12Cd3, monoclinic C2/c, a = 20.130(4) Angstrom, b = 6.692(13) Angstrom, c = 13.081(3) Angstrom, beta = 102.78(3)degrees, Z = 4. Both compounds exhibit novel three-dimensional frameworks. Compound 1 not only possesses a one-dimensional rectangular channel but also contains infinite double-stranded helical chains. Compound 2 has two different types of channels, one being built up from pyridine rings and {CdO5N} and {CdO6} building units and the other being constructed from pyridine rings and {CdO5N} building units. Furthermore, both compounds show strong photoluminescence properties at room temperature.