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“Blebbing” of a Gold Nanocluster by Dioxygen Insertion into Thiolate Staples during Self-Photooxidation

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide In our work with a Au thiolate nanocluster (Au 20 (SG) 16, where SG is the tripeptide glutathione), we noticed that it underwent a self-photooxidation reaction in the presence of white light and oxygen. We now report on mechanistic studies using photophysical, photochemical, theoretical, and indirect trapping methods. We find rapid total quenching of singlet oxygen ( 1 O 2 ) by ground-state Au 20 (SG) 16, with evidence of dioxygen insertion into the nanocluster. Supported by analyses with IR, ESI-MS, and density functional theory, we propose the formation of Au–O–O–SG bonds in the Au nanocluster. The expansion of the staple motif from dioxygen insertion is attributed to heightened lability and blebbing (a protrusion) arising from the O–O group. We then demonstrated that the self-photooxidized Au 20 (SG) 16 undergoes oxygen-atom transfer to a phosphine trap in the dark.

Source: The Journal of Physical Chemistry A

DOI: 10.1021/acs.jpca.5c06629

Authors: Serah Essang, Alexander Greer

Institutions: The Graduate Center, CUNY, City University of New York, Brooklyn College

Language: English

Topic: Nanocluster Synthesis and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, Office of Advanced Cyberinfrastructure, Division of Chemistry, Division of Advanced Cyberinfrastructure