Chemically modified thin organic films supported on polished silica substrates

Abstract

Organic films, of thickness up toca. 1000 nm, derived from polycyclic aromatic hydrocarbons containing 3–15 rings, have been grown on highly polished silica glass supports by vacuum sublimation. The quality of the films, as judged by their electronic spectra, is very dependent on achieving a near subnanometre surface finish on the silica. Exposure of the films to MoF₆ at room temperature results in irreversible adsorption of the latter, as demonstrated by electronic spectroscopy. The fluorides WF₆ and AsF₅ show similar behaviour, although in many cases their interactions with the films are less marked.