Solvothermal Synthesis and Diverse Coordinate Structures of a Series of Luminescent Copper(I) Thiocyanate Coordination Polymers Based on N-Heterocyclic Ligands

Solvothermal reactions of CuSCN with 4-amine-3,5-bis(3-pyridyl)-1,2,4-triazole (3-Abpt), 5-(4-pyridyl)tetrazole (4-Ptz), and 2-(n-pyridyl)benzimidazole (n-PyHBIm, n = 4, 3, 2) in acetonitrile afford six novel coordination polymers: [Cu-5(SCN)(5)(3-Abpt)(2)](n) (1), [Cu(SCN)(3-Abpt)](n) (2), [Cu(SCN)(4-Ptz)](n) (3), [Cu-2(SCN)(2)(4-PyHBIm)](n) (4), [Cu-2(SCN)(2)-(3-PyHBIm)](n) (5), and [Cu-2(SCN)(2)(2-PyBIm)(2-PyHBIm)](n) (6). All these complexes were structurally characterized by X-ray diffraction analysis. I is the first example of a 1,1,1,3-mu(4)-tetradentate thiocyanate complex which displays a three-dimensional (313) polymeric framework constructed from thiocyanate kind tetradentate 3-Abpt. 2 exhibits it two-dimensional (2D) 4.8(2) network constructed from unidentate thiocyanate and tridentate 3-Abpt. 3 is a one-dimensional (I D) ladder-like double-chain polymer assembled by bidentate thiocyanate and 4-Ptz ligands. 4 shows a 2D 1,1,3-mu(3)-thiocyanate copper 4.8(2) network where bidentate 4-PyHBIm locates at both sides of the 2D layer. 5 displays a 2D 6 3 network constructing from 1, 1,3-mu(3)-thiocyanate kind bidentate 3-PyHBIm. 6 is a 1D 2(1) helical chain polymer constructing from 1,3-mu(2)-thiocyanate and 2-PyBIm anion. Bond valence sum (BVS) analysis and magnetic susceptibility indicate that 6 is a mixed-valence compound. The coordinate diversity of thiocyanate is discussed. 1-6 are all thermally stable up to 230-290 degrees C. They exhibit yellow or blue luminescence originating from ligand-to-metal charge transfer or ligand-centered emission.