Synthesis, structures and thermal dependence of photoluminescence of copper(I) halide metallacycle and 1-D chain complexes

In this work, we report the synthesis, X-ray crystal structures, and temperature dependence of solid-state photoluminescence properties of two cuprous iodide complexes, namely, [(mpbi)CuI]n (1) and [(bimb)CuI]n (2) (mpbi = 1,1′-(5-methyl-1,3-phenylene)bis (1H-imidazole), bimb = 1,2-bis((imidazole-1-yl)methyl)benzene). The complexes exhibit efficient solid-state emission at room temperature, with peak emission wavelengths at 580 and 650 nm, respectively. Two complexes display outstanding thermal stability. The X-ray diffraction analysis revealed that the structure of 1 is a discrete metallacycle with the copper atom in the structure adopting a less common triangular configuration, while the structure of 2 is a one-dimensional chain structure of Cu2I2 binuclear rhomboid. The temperature dependence of photoluminescence in the wide temperature range is investigated, which demonstrates that the thermal quenching of luminescence of copper complexes can be regulated by cuprophilic interaction.