Chemical functionalisation and arrangement of ultrasmall gold clusters in Langmuir-Blodgett films

Phosphine ligand-stabilised gold clusters with core diameters in the region of 1-3 nm were embedded in a polymer Langmuir film matrix and deposited onto substrates suitable for TEM investigation. The Langmuir layers were either transferred from pure water or a subphase containing a thiol ligand. There is evidence for ligand exchange without the decomposition of the cluster material. TEM images reveal different lateral cluster arrangements in dependence of the subphase composition and the presence of head group charges in the polymer matrix. In addition, the size distribution of the clusters is affected by thiol addition to the subphase leading to smaller particles with a decreased size variation. (C) 1998 Elsevier Science B.V.