Magic-numbered Aun clusters protected by glutathione monolayers (n=18, 21, 25, 28, 32, 39): isolation and spectroscopic characterization

Whetten and co-workers fractionated gold clusters protected by monolayers of glutathione (GSH=gamma-Glu-Cys-Gly) by using polyacrylamide gel electrophoresis (PAGE) and identified the most abundant species as Au28(SG)16 by mass spectrometric characterization of electrophoratically fractioned Au:SG clusters. Results provide basic guidelines for studies on structures, stabilities and optical properties of small gold MPC's as well as for development of new cluster based materials.