Quantitative Analysis of Photochemical Reactions in Pentacene Precursor Films

Abstract

On-surface reactions are rapidly gaining attention as a chemical technique for synthesizing organic functional materials, such as graphene nanoribbons and molecular semiconductors. Quantitative analysis of such reactions is essential for fabricating high-quality film structures, but until our recent work using p-polarized multiple-angle incidence resolution spectrometry (pMAIRS), no analytical technique is available to quantify the reaction rate. In the present study, the pMAIRS technique is employed to analyze the photochemical reaction from 6,13-dihydro-6,13-ethanopentacene-15,16-dione to pentacene in thin films. The spectral analysis on a pMAIRS principle readily reveals the photoconversion rate accurately without other complicated calculations. Thus, this study underlines that the pMAIRS technique is a powerful tool for quantitative analysis of on-surface reactions, as well as molecular orientation.

Multiple-angle incidence resolution spectrometry: applications in nanoarchitectonics and applied physics

“…Therefore, from the intensity of the OI spectrum, the quantitative changes of chemical species associated with chemical reactions can be analyzed in the thin film. 106,[134][135][136] This further makes it possible to estimate thermodynamic constants such as rate constants and activation energies. 135) In the following, we will introduce examples of studies in which the pMAIRS technique is applied to the analysis of on-surface reactions.…”