DFT investigation on electronic structure, chemical bonds and optical properties of Cu6(SR)6 nanocluster

The orbital interaction between two fragments of Cu6 and (SR)6. [Display omitted] •Bonds between Cu6 core and ligands (SR)6, with bond order of about 0.6 for Cu-N and Cu-S bonds, contributed to the stabilization of the copper cluster.•The orbital interaction between Cu6 core and ligands (SR)6 significantly change the electron distribution of copper core and made the copper cluster have the special optical and electronical characters.•The UV–visible absorption peaks mainly came from the electron excitation from metal core Cu6 and 6 S atoms to the ligands (SR)6. Compared with gold and silver nanoclusters, copper nanoclusters (Cu NCs) have incomparable price advantages. As a new type of photoluminescence and nanocatalysis materials, copper nanoclusters have attracted more and more attention in the fields of photoluminescence analysis, biological probe imaging and catalysis. In this work the electronic structures of Cu6(SR)6-1 and Cu6(SR)60 nanoclusters, chemical interaction between metal core Cu6 and ligands (SR)6 and optical properties of the nanocluster were studied using quantum mechanical calculation method which can be helpful for us to understand the electronical properties in the nanocluster and design the new nanocluster structure with desired properties.