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.