Ligand effects in photoluminescence of copper nanoclusters

OPhS). Interestingly, the photoluminescence lifetime of Cu9-2 was found to be 3.2 times longer than that of Cu9-1. Furthermore, a notable Stokes shift (ST) was observed in the emission spectra of the two clusters. Single-crystal X-ray analysis revealed the formation of hydrogen bonds between neighboring clusters of Cu9-2, which influenced intramolecular interactions. Additionally, the methoxy groups in Cu9-2, acting as conjugated electron donors, promoted intramolecular charge transfer and π-π interaction. This study is expected to inspire further research on surface ligand engineering for controlling the properties of copper nanoclusters beyond photoluminescence.