Synthesis, structure and photoluminescence properties of three copper(I) iodide based inorganic–organic hybrid structures with pyrazine derivatives

By using pyrazine derivatives, three different types of copper(I) iodide based inorganic–organic hybrid structures, 1D-CuI(2-mo-pz) (1, 2-mo-pz = 2-methoxy-pyrazine), 2D-CuI(2,3-dm-pz)0.5 (2, 2,3-dm-pz = 2,3-dimethyl-pyrazine), and 2D-Cu2I2(2,5-dm-pz)2 (3, 2,5-dm-pz = 2,5-dimethyl-pyrazine), have been obtained by using a slow-diffusion method. Single crystal and powder X-ray diffraction analyses reveal that these hybrid structures are a one-dimensional (1D) staircase chain based structure, two-dimensional (2D) staircase-chain based structure, and 2D rhomboid dimer based structure, respectively. All of the three compounds show photoluminescence, with the internal quantum yield (IQY) as high as 88.2% for 1. This work provides evidence that for this type of hybrid materials, the structure of the inorganic module could be determined by the selection of the organic ligands and that the substituted group on the organic ligands can influence the luminescence efficiency of the hybrid structures.