ELECTRON HOPPING AND ELECTRONIC CONDUCTIVITY IN MONOLAYERS OF ALKANETHIOL-STABILIZED GOLD NANO-CLUSTERS AT THE AIR WATER INTERFACE/

Morphology of Langmuir monolayers of gold clusters stabilized with a s eries of alkanethiols was investigated at the air/water interface with Brewster Angle Microscopy which revealed substantial differences depe nding on the length of the alkyl chains (clusters stabilized with C-8 and C-14 thiols were investigated). 2D electrochemical measurements ca rried out with line micro-band electrodes showed negligible electronic conductivity of all monolayers even in their most compressed state, a pparently due to the presence of the stabilizing alkyl chains on the s urface of the clusters. The same electrochemical measurement showed, h owever, full redox conductivity in the monolayers of gold nano-cluster stabilized with alkanethiols, 20% of which were terminated with ferro cene. In those cases, redox conductivity is supported by a facile elec tron hopping (self-exchange rate constant was measured to be greater t han or equal to 4.4 x 10(6) M-1 s(-1)) between neighboring ferrocene/f errocenium sites.