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 d10 metal coordination polymers [Zn(PDB)]n (1) and [Cd3(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 Pna21, a = 8.423(17) Å, b = 6.574(13) Å, c = 12.899(3) Å, Z = 4. Crystal data for 2: C14H12N2O12Cd3, monoclinic C2/c, a = 20.130(4) Å, b = 6.692(13) Å, c = 13.081(3) Å, β = 102.78(3)°, 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.