Dynamic stabilization of the ligand-metal interface in atomically precise gold nanoclusters Au68 and Au144 protected by meta mercapto benzoic acid

2017年07月03日

报告题目:Dynamic stabilization of the ligand-metal interface in atomically precise gold nanoclusters Au68 and Au144 protected by meta mercapto benzoic acid

报告人:Prof. Hannu Häkkinen, University of Jyväskylä

时间:7月12日(周三)下午4:00

地点:卢嘉锡楼202报告厅

报告摘要:

Ligand-stabilized, atomically precise gold nanoclusters with a metal core of a uniform size of just 1 – 3 nm are a fundamentally new class of nanomaterials amenable, for instance, for accurate site-specific conjugation to biomolecules. Previously, it has been shown that monodispersed gold nanoclusters, stabilized by meta mercapto benzoic acid (m-MBA or 3MBA) ligands and with sizes of 68 to 144 gold atoms, offer optimal ambient stability and affinity to cysteine-exposing proteins and to thiol-modified DNA. Here we show that a combination of nuclear magnetic resonance spectroscopy, ultraviolet-visible absorption, infrared spectroscopy, molecular dynamics simulations and density functional theory calculations reveal a low-symmetry C1 ligand layer of 3MBA around the gold core of Au68 and Au144. 3MBA protects the metal core not only by the covalent S-Au bond formation but also via weak p – Au and O=C-OH...Au interactions. The p – Au and -OH...Au interactions have a strength of the order of a hydrogen bond, thus are dynamic in water at ambient temperature. Our results lay a foundation to understand functionalization of atomically precise gold nanoclusters for bioconjugation or catalysis via a route where weak ligand-metal interfacial interactions are sacrificed for covalent bonding.

报告人简介:

Hannu Häkkinen, academy professor of the Academy of Finland. He obtained his M.S. and Ph.D. in physics from university of Jyväskylä, Finland. He has been published about 210 articles in peer-reviewed journals with several in high-impact journals (e.g. 2 in Science, 2 in the PNAS, 1 in Nature Materials, 2 in Nature Chemistry, 3 in Nature Communications and so on). Total number of citations is close to 14000 (62 per paper). He is one of the most-cited researchers in the University of Jyväskylä. The most cited paper has over 1000 citations. His research focuses on computational nanoscience, methods of electronic structure calculations of nanoparticles, nanostructures and solids; electronic, optical, magnetic, chemical and catalytic properties of bare, supported, and ligandprotected metal nanoparticles, electrical conductivity of molecule-metal interfaces in nanostructures, properties of carbon nanotubes and graphene; and structural and chemical properties of metal nanoparticle/bionanoparticle (virus) hybrids.