Diversity of Architecture of Copper(I) Coordination Polymers Constructed of Copper(I) Halides and 4-Methyl-1,2,4-Triazole-3-Thiol (Hmptrz) Ligand: Syntheses, Structures, and Luminescent Properties

Solvo(hydro)thermal reactions of CuX (X = Cl, Br, I) with 4-methyl-1,2,4-triazole-3-thiol (Hmptrz) ligand afforded four new copper(I) coordination polymers, namely, [Cu(mu(4)-mptrz)](n) (1), [Cu(mu(2)-Hmptrz)(mu(2)-I)](n) (2), [Cu-12(mu(4)-mptrz)(4)-(mu(4)-I)(3)(mu(3)-I)(4)(mu(2)-I](n), (3), and [Cu(mu(2)-Hmptrz)(mu(2)-DmptrzSS)I](n) (4) (DmptrzSS = 4,4'-dimethyl-3,3'-dithiodi-1,2,4-triazole), respectively. Single-crystal X-ray diffraction revealed that compound 1 has a two-dimensional (2D) layered structure with topology and contains meso-helical (CuS)(n) chains. Compound 2 features a one-dimensional (1D) chain structure constructed from an unusual inorganic [Cu(mu(2)-S)(2)Cu(mu(2)-I)(2)Cu](n) chain formed from two types of four-membered Cu-2(mu(2)-S)(2) and Cu-2(mu(2)-I)(2) rings. Compound 3 is a two-dimensional (2D) structure constructed from rugby-shaped Cu6I5 and planar Cu4I3 cluster units, and two types of Cu(mptrz)(2) units. The I- ion in structure 3 displays its coordination versatility with mu(4)-, mu(3)-, and mu(2)- bridging coordination modes. Compound 4 has a double-stranded chain structure containing an Hmptrz ligand and DmptrzSS ligand formed from in situ reaction. The structural diversity of these materials is reflected in the variety of coordination polyhedra displayed by the metal sites: linear, trigonal, and tetrahedral. Compounds 1-3 exhibit photoluminescences with fluorescent emissions varying from green to red in the solid state. Some structure-related emission shifts compared to the free ligand are studied. The reaction mechanism of the formation of DmptrzSS ligand has been proposed. In addition, elemental analysis, infrared spectra, and thermogravimetric analysis of compounds 1-4 are also described.