SELF-ASSEMBLY OF ORGANIC FILMS ON A LIQUID-METAL

THE structure and phase behaviour of organic thin films result from th e subtle interplay of intermolecular Van der Waals interactions, which promote self-assembly and long-ranged order, and the more complex int eractions between the end groups bf the organic chains and the substra te. The structure of molecular films of amphiphiles has been extensive ly studied on subphases of dielectric liquids, notably water (Langmuir monolayers) and on solid surfaces (self-assembled monolayers, SAMs)(1 -4). Here we report structural studies, by synchrotron X-ray re scatte ring, of an Intermediate case: densely packed alkanethiol films on the surface of liquid mercury, White, like SAMs, these films form strong chemical bonds to the subphase, this subphase is smooth and unstructur ed, as in the case of Langmuir monolayers, But unlike either of these( 1,2,5-7), our films have no inplane long-range order, We suggest that the strong interaction of the thiol group with the underlying disorder ed liquid dominates here over the order-promoting interactions of the alkyl chains.