A Research Paper Published in Polymer

In this paper, the possibility of polymerization of various aromatic dinitroso derivatives initiated by nitroso-terminated monolayer on gold surface was investigated by using ellipsometry, atomic force microscopy (AFM) and nano-FTIR spectroscopy. Ellipsometry showed an increase in film thicknesses after nitroso groups exposed at the monolayer interface were subjected to interactions with aromatic dinitroso derivatives in solution. The obtained film thickness values indicated formation of azodioxy oligomer films composed of only a few monomeric subunits with possibly tilted and intertwined chains. Ellipsometry data were corroborated with AFM topography images which revealed the appearance of a high number of islands, attributed to domains of azodioxy oligomers. Both techniques revealed that the formation of azodioxy oligomers on the gold surface is more pronounced with a longer adsorption time. Valuable information about the nanoscale chemical composition of films was extracted from nano-FTIR spectra in which the bands corresponding to the stretching vibrations of the E-azodioxy bond were observed, which, among other, demonstrated the high sensitivity of nano-FTIR spectroscopy for the chemical identification of very thin films. Furthermore, due to the interesting electronic properties of some of the aromatic dinitroso derivatives used here, this study could serve as a starting point for conductivity measurements of adsorbed azodioxy oligomers and their potential application as organic semiconductors.

The research was supported by Croatian Science Fundation within the project From nitrogen-containing aromatic compounds to new functional organic-based materials (FunMaterials, IP-2020-02-4467).