Anion-mediated self-assembly: Five Cd(ІІ) coordination aggregates with a mercaptotetrazole ligand

Five Cd(II) complexes, {[Cd4(MTZ)2(H2O)2Cl8]·0.5H2O}n (1), [Cd(MTZ)2Br2] (2), [Cd2(MTZ)2I4] (3), [Cd2(MTZ)2(H2O)8] (SO4)2 (4), {[Cd(MTZ)2(H2O)2](ClO4)2}n (5), based on different anions with the mercaptotetrazole ligand MTZ (MTZ = 1-(2-dimethylamino-ethyl)-5-mercapto-1H-tetrazole) have been synthesized. Employment of different anions can result in structural diversity in 1–5. In 1, the Cd(II) ions make use of μ2-Cl, μ3-Cl bridging each other to form a novel Cd4Cl8 inorganic network structure. On the other hand, the 2D structure is further stabilized by MTZ as a tridentate bridging organic ligand holding three adjacent Cd(II) ions. In 2, MTZ as a terminal ligand coordinates with a Cd(II) ion to form a mononuclear structure. As a μ2, η2 bridging ligand, MTZ links Cd(II) ions to form a dimeric structures in 3 and 4, and a 1D infinite chain in 5. In addition, the luminescent properties of 1–5 have been investigated in the solid state at room temperature.

We have designed and synthesized five Cd(II) complexes (1–5) with 0D–1D infinite chains and 2D network structures based on different anions with MTZ [MTZ = 1-(2-dimethylamino-ethyl)-5-mercapto-1H-tetrazole]. The luminescent properties of the complexes have also been investigated in the solid state at room temperature.Figure optionsDownload as PowerPoint slideHighlights
► We have synthesized five Cd(II) complexes based on a mercaptotetrazole ligand.
► Anion-mediated self-assembly exist in the five complexes.
► The introduction of anions has influence on the coordination mode of the ligand.
► Both anions and structures of complexes further affect the fluorescent properties.