02578nas a2200217   4500008004100000022001400041245015200055210006900207260000800276490000700284520173800291653003002029653003702059653003002096653001702126100002502143700002202168700002602190700001802216856012602234       2024                        eng d  a0934-086600aUltra-small Au nanoclusters with tailored photoluminescence properties using modified thiol ligands: a computational and experimental demonstration0 aUltrasmall Au nanoclusters with tailored photoluminescence prope  cOCT0 v413 a<p>
	Au nanoclusters with tailored photoluminescence can be obtained through controlled nanoparticle ligand interface chemistry. The present work reports molecular gold nanoclusters with tuneable photoluminescence emission from 600 to 700 nm using N,N `,N `'-trialkyl (11-mercaptoundecyl)ammonium chloride ligands as capping-agents. The tunability within red spectral region is regulated through specific interface chemistry between gold nanoclusters of molecular range and functional groups of the quaternary ammonium head over N,N `,N `'-trialkyl(11-mercaptoundecyl)ammonium chloride. Combined understanding obtained from the spectroscopy, microscopy, and density functional theory studies demonstrate that the functional group specific electronic interactions at the interfaces steer the emission characteristics of ``molecular'' Au nanoparticles. The study clearly identifies that bulkier functional groups, i.e., triethyl, tripropyl, tributyl, and dimethyl benzene over N+ (of thiol ligand) through their steric effects minimize the particle size giving rise to tunable photoluminescence emission in red spectral region. However, the red shift seen in the emission Au nanoclusters with N-(11-mercaptoundecyl)-N,N `-dimethylbenzenammonium chloride ligand in contradiction to particle size effect is computationally proved to be due to the delocalization of electron density from benzene aromatic ring to N+ of ammonium head leading to a reduction in the HOMO-LUMO energy gap. Fluorescence properties of water dispersible Au nanoclusters are tuned by varying the ammonium head group. Density Functional Theory studies correlate the distinction in emission when head group is phenyl to charge transfer characteristics. image</p>
10aDensity functional theory10aphotoluminescent Au nanoclusters10asurface plasmon resonance10athiol ligand1 aChahande, Anurag, M.1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aDevi, Nandini  uhttps://library.ncl.res.in/content/ultra-small-au-nanoclusters-tailored-photoluminescence-properties-using-modified-thiol