Effect of Protons on the Redox Chemistry of Colloidal Zinc Oxide Nanocrystals
Electron transfer (ET) reactions of colloidal 3–5 nm diameter ZnO nanocrystals (NCs) with molecular reagents are explored in aprotic solvents. Addition of an excess of the one-electron reductant Cp*2Co (Cp* = pentamethylcyclopentadienyl) gives NCs that are reduced by up to 1–3 electrons per NC. Prot...
Gespeichert in:
Veröffentlicht in: | Journal of the American Chemical Society 2013-06, Vol.135 (23), p.8492-8495 |
---|---|
Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Electron transfer (ET) reactions of colloidal 3–5 nm diameter ZnO nanocrystals (NCs) with molecular reagents are explored in aprotic solvents. Addition of an excess of the one-electron reductant Cp*2Co (Cp* = pentamethylcyclopentadienyl) gives NCs that are reduced by up to 1–3 electrons per NC. Protons can be added stoichiometrically to the NCs by either a photoreduction/oxidation sequence or by addition of acid. The added protons facilitate the reduction of the ZnO NCs. In the presence of acid, NC reduction by Cp*2Co can be increased to over 15 electrons per NC. The weaker reductant Cp*2Cr transfers electrons only to ZnO NCs in the presence of protons. Cp*2M+ counterions are much less effective than protons at stabilizing reduced NCs. With excess Cp*2Co or Cp*2Cr, the extent of reduction increases roughly linearly with the number of protons added. Some of the challenges in understanding these results are discussed. |
---|---|
ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/ja4035945 |