Two anionic [CuI6X7]nn- (X=Br and I) chain-based organic-inorganic hybrid solids with N-substituted benzotriazole ligands

Solvothermal reactions of the flexible ligand 1,6-Bi(benzotriazole)hexane with CuI and KI or CuBr and KBr in ethanol generate two hybrid compounds, namely, {(HETA)[(Cu6I7)(ETA)2]}n(1) and {K(Cu6Br7)(BBTH)}n(2) (ETA=N-ethylbenzotriazole, HETA=protonated N-ethylbenzotriazole, BBTH=1,6-bi(benzotriazole)hexane). In 1, two [Cu3I4] vertex missing cubane-like subunits link each other by sharing one I atom to give a [Cu6I7] cluster, which further form novel 1D [Cu6I7]nn- anionic chain. Two in-situ generated ETA ligands finished the 4-coordinated environments of copper centers and another one discrete protonated ETA ligand keeps the charge neutrality for 1. In complex 2, bowl-shaped [Cu5Br4] clusters and rhomboid [Cu2Br2] dimers link each other to generate a [Cu6Br7]nn- 1D chain. BBTH ligands complete the tetrahedral spheres of Cu(I), and 7-coordinated K atoms further extend the 1D chain motifs to a 2D hybrid layer of 2. The UV-vis diffuse reflectance spectrum and luminescence measurements show that compound 1 and 2 both are potential semiconductor and photoluminescence materials. - Graphical abstract: Two unprecedented anionic [CuI6X7]nn- (X=Br and I) chain-based organic-inorganic hybrid solids, namely, {(HETA)[(Cu6I7)(ETA)2]}n (1) and {K(Cu6Br7)(BBTH)}n(2) (ETA=N-ethylbenzotriazole, HETA=protonated N-ethylbenzotriazole, BBTH=1,6-bi(benzotriazole)- hexane) have been synthesized under solvothermal reactions and characterized.