Sequential Growth as a Mechanism of Silver-Glutathione Monolayer-Protected Cluster Formation.

Autor: Zaker Y; Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH, 43606, USA., Ashenfelter BA; Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH, 43606, USA., Bhattarai B; Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH, 43606, USA., Diemler NA; Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH, 43606, USA., Brewer TR; Department of Chemistry, Eastern Michigan University, Ypsilanti, MI, 48197, USA., Bigioni TP; Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH, 43606, USA.; The School of Green Chemistry and Engineering, University of Toledo, Toledo, OH, 43606, USA.
Jazyk: angličtina
Zdroj: Small (Weinheim an der Bergstrasse, Germany) [Small] 2021 Jul; Vol. 17 (27), pp. e2002238. Date of Electronic Publication: 2020 Aug 28.
DOI: 10.1002/smll.202002238
Abstrakt: Silver monolayer-protected clusters (MPCs) are an important new class of small metal nanoparticles with discrete sizes and unique properties that are eminently tunable; however, a fundamental understanding of the mechanisms of MPC formation is still lacking. Here, the basic mechanism by which silver-glutathione MPCs form is established by using real-time in situ optical measurements and ex situ solution-phase analyses to track MPC populations in the reaction mixture. These measurements identify that MPCs grow systematically, increasing in size sequentially as they transform from one known species to another, in contrast to existing models. In the new sequential growth model of MPC formation, the relative stability of each species in the series results in thermodynamic preferences for certain species as well as kinetic barriers to transformations between stable sizes. This model is shown to correctly predict the outcome of silver MPC synthetic reactions. Simple analytic expressions and simulations of rate equations are used to further validate the model and study its nature. The sequential growth model provides insights into how reactions may be directed, based on the interplay between relative MPC stabilities and reaction kinetics, providing tools for the synthesis of particular MPCs in high yield.
(© 2020 Wiley-VCH GmbH.)
Databáze: MEDLINE
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