Influence of Halogen–Solvent Hydrogen Bonding on Gold Nanocluster Photoluminescence

The influence of gold nanocluster–solvent interactions on nanostructure optical properties was determined. Using [Au11(BINAP)4X2]+, where X = Cl or Br, as a model system, the dramatic influence of halogen–solvent hydrogen bonding on nanocluster optical properties was resolved. The creation of a nanocluster–solvent hydrogen-bond network yielded intense photoluminescence (PL) and an accompanying 2-fold reduction in vibration-mediated nonradiative decay rates. PL was quenched for systems that did not support hydrogen bonding. As reflected by absorption line widths, Raman scattering, and transient absorption spectroscopy measurements, the hydrogen-bond network increased nanocluster structural rigidity and reduced nonradiative carrier decay rates. The results highlight the significant role of the nanocluster–solvent interface in determining the properties of structurally precise materials.