Low-Dimensional Hybrid Cuprous Halides Directed by Transition Metal Complex: Syntheses, Crystal Structures, and Photocatalytic Properties

By using transitional metal (TM) complex cations as structure-directing agents, a series of new hybrid cuprous halides with abundant architectures ranging from one-dimensional (1D) ribbons to two-dimensional (2D) layers have been solvothermally prepared and structurally characterized. Compounds [TM­(2,2-bipy)3]­Cu5I7 (TM = Fe (1), Co (2), and Ni (3)) feature 1D [Cu5I7]2– chains formed by the interconnection of [Cu5I10] units via edge-sharing. In compounds [TM­(2,2-bipy)2I]2Cu7I9 (TM = Mn (4), Cu (5), and Ru (6)), the [Cu5I9] units and [Cu2I6] dimers are alternately interlinked via edge-sharing to form the 1D [Cu7I9]2– chains. Compound [Cu­(2,2-bipy)2I]­[(Me)2-2,2-bipy]­Cu8I11 (7) contains a new 1D [Cu8I11]3– chain composed of complex [Cu8I13] units based on CuI4 tetrahedra and CuI3 triangles. Compound [Co­(2,2-bipy)3]­Cu5Br8 (8) features 1D [Cu5Br8]3– anionic chain built from the interconnection of [Cu6Br10] units and linear [Cu4Br8] tetramers. In compound K­[Mn­(2,2-bipy)3]2Cu6I11 (9), the [Cu3I7] secondary building units are directly interconnected to form 2D [Cu6I11]5– layers, which are further interconnected by K+ ions via weak K–I bonds to generate a 3D [K@Cu6I11]4– framework with 1D large channels occupied by [Mn­(2,2-bipy)3]2+ complexes. The UV–vis diffuse reflectance measurements reveal that the title compounds possess semiconductor behaviors with smaller band gaps of 1.44–1.95 eV, and samples 4, 5, and 9 show highly efficient photocatalytic degradation activities over organic pollutant than N-doped P25 under visible-light irradiation.