Synthesis, structure and luminescent properties of two three-dimensional d10 metal complexes constructed from pyridine-3,4-dicarboxylic acid with new network topologies

Two novel three-dimensional d(10) metal coordination polymers [Zn-2(pydc)(2)(DMF)(3)](n) (1) and [Cd-2(pydc)(2)(H2O)](n) (2) (H(2)pydc=pyridine-3,4-dicarboxylic acid, DMF=N,N-dimethylformamide) have been synthesized under solvothermal and hydrothermal conditions, and characterized by elemental analysis, IR, TG analysis and single crystal X-ray diffraction. Compound 1 exhibits a complex three-dimensional framework containing one-dimensional elliptic channels occupied by coordinated DMF molecules. In complex 2, adjacent sheets constructed by carboxyl-bridged Cd-O-Cd chains are pillared by pydc ligands into a three-dimensional network. From a topological point of view, the two three-dimensional nets display (3,4)-connected (6.8(2))(2)(6.8(5)) and 4-connected (4.8(5))(4(2).6.8(3))(2)(4(3).6(2).8) topologies, respectively, which are unprecedented within coordination frames. Furthermore, both compounds show intense fluorescent emissions upon photoexcitation at room temperature. (c) 2006 Elsevier B.V. All rights reserved.