Location Of Cu Atom In Au-Based Nanocluster And Its Optical Properties

Atomically precise alloy nanoclusters are one of the important nanomaterials, benefiting to investigate the structure-property correlations at atomic level. Herein, we reported Au19Cu2(SR)(15) (SR: adamantanethiol) alloy nanocluster. The crystal structure of Cu-Au nanoclusters was determined by X-ray crystallography and the molecular mass was further characterized via Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS). The crystal structure shows the kernel of bi-octahedrons Au-10 capped by a Au6Cu2(SR)(9) motif, a Au-2(SR)(3) motif, a Au(SR)(2) motif and one S atom. It was observed that two Au atoms in the longest Au6Cu2(SR)(9) motif were replaced with two Cu atoms. Moreover, we explored optical properties of Au19Cu2(SR)(15) by UV-vis absorption spectroscopy and fluorescence spectroscopy. Alloy nanocluster exhibits a strong emission at 700 nm. This work provides insights into the synthesis and the enhanced properties of Au-Cu alloy nanoclusters.