Twelve Cadmium(II) Coordination Frameworks with Asymmetric Pyridinyl Triazole Carboxylate: Syntheses, Structures, and Fluorescence Properties

Based on an asymmetric pyridinyl triazole carboxylate ligand 1-(4-pyridinylmethyl)-1H-1,2,4-triazole-3-carboxylic acid (Hpmtc), 12 cadmium(II) polymers {Cd-1.5(pmtc)(2)(NO3)]center dot H2O} (1), {[cd2(pmtc)2(mu(2)-SO4)(H2O)]} (2), [cd(pintc)(scN)](n) (3), [Cd-2(pmtc)(2)(SCN())2], (4), {[Cdi.s(pmtc)2(N-3)].1-120} (5),{[Cd(pmtc)2]} (6), [Cd(Prntc)(NO2)(CH3OH)1, (7), I [cd(2)(PPmtc)(3)(NO2)(1)} (8), {[Cd-2(pmtc)(2)(C-1)(2)(H2O)(2)lin (9),{[Cd(pmtc)(Br)(H2O)]CH3OH} (10), {Cd(pmtc)(I)(H2O)]} (11), and [Cd(pmtc)-(I)(n)] (12) have been synthesized and structurally characterized. Employment of different anions has resulted in different architectures and topological structures, ranging from twodimensional (2D) to three-dimensional (3D) frameworks, in which 2 and 4 present a new (4(2.)6.10(3))(4(2)-6(3)-8)(2)(4(2)-6) topology. Through calculations to the frontier molecular orbital (FMOs) of 9-11, their photoluminescence should be assigned as the n -> pi* transition. Moreover, the photoluminescent properties of 1-12 indicate that the coordination anions make great contribution to fluorescent emission of Cd(II) polymers.