Regular Article

Structural insights into glutathione-protected gold Au₁₀₋₁₂(SG)₁₀₋₁₂ nanoclusters revealed by ion mobility mass spectrometry^★,★★

¹ Institut lumière matière, UMR 5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex, France
² Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, 69100 Villeurbanne, France

^a e-mail: rodolphe.antoine@univ-lyon1.fr

Received: 23 March 2018
Received in final form: 8 June 2018
Published online: 28 August 2018

Abstract

Gold nanoclusters protected by ligands present well-defined compositions and tunable structures, which builds a solid basis for correlation between structures and properties. We report a combined ion mobility-mass spectrometry approach for the analysis of ultra-small gold nanoclusters protected by glutathione (SG) as ligand molecules, Au₁₀₋₁₂(SG)₁₀₋₁₂. Collision cross section (CCS) measurements are reported for different charge states for Au₁₀(SG)₁₀, Au₁₁(SG)₁₁ and Au₁₂(SG)₁₂ nanoclusters. Computational calculations, at the PM7 semi-empirical level of theory, are performed to optimize geometrical structures and use them to compute CCS. The comparison of the experimentally and theoretically determined CCS allows drawing conclusions on the structural changes, in particular partial unfolding of SG ligands, upon charging.