This paper is published as part of a PCCP Themed Issue on: Physical Chemistry of Ionic Liquids

Received 13th October 2009, Accepted 1st March 2010First published as an Advance Article on the web 7th April 2010DOI: 10.1039/b921368fWe present the first kinetic study of quantised double layer charging of monolayer-protectedgold clusters in an ionic liquid. Cyclic voltammetry and electrochemical impedance measurementsreveal that kinetic control is involved in the quantised cluster charging in these room temperaturemelts. The level of kinetic control varies up to one order of magnitude depending on ionic liquidcomposition, which may have implications for the development of future nanoelectronic devices.By studying the quantised charging process in the chemically relevant permutations of two anionsand two cations, we find strong indications that the ionic liquid behaviour is not a linearcombination of its composing ions’ properties, but is dominated by specific interactions. Basedon a Walden plot analysis, we hypothesise that the chemical availability of ions is different in thevarious liquids, and explains the differences in monolayer-protected gold cluster (MPC)charging rates.