We present the spontaneous isomerization of donor-acceptor Stenhouse adducts anchored onto a gold surface, visualized using scanning tunneling spectroscopy. Our investigation reveals a palette of molecular arrangements, including those with ferroelectric-like ordering, evolving over time into a fine pattern consisting of both open and closed forms of the photoswitch.
View Article and Find Full Text PDFUnderstanding nanoscale mechanisms responsible for the recently discovered ferroelectric nematics can be helped by direct visualization of self-assembly of strongly polar molecules. Here, we report on scanning tunneling microscopy studies of monomolecular layers of a ferroelectric nematic liquid crystal on a reconstructed Au(111) surface. The monolayers are obtained by deposition from a solution at ambient conditions.
View Article and Find Full Text PDFCombining STM measurements on three different substrates (HOPG, MoS, and Au[111]) together with DFT calculations allow for analysis of the origin of the self-assembly of 4-cyano-4'-n-decylbiphenyl (10CB) molecules into kinked row structures using a previously developed phenomenological model. This molecule has an alkyl chain with 10 carbons and a cyanobiphenyl group with a particularly large dipole moment. 10CB represents a toy model that we use here to unravel the relationship between the induced kinked structure, in particular the corresponding chirality expression, and the balanced intermolecular/molecule-substrate interaction.
View Article and Find Full Text PDFWe investigate the expression of chirality in a monolayer formed spontaneously by 2,3,6,7,10,11-pentyloxytriphenylene (H5T) on Au(111). We resolve its interface morphology by combining scanning tunneling microscopy (STM) with theoretical calculations of intermolecular and interfacial interaction potentials. We observe two commensurate structures.
View Article and Find Full Text PDFThe light-induced and STM-tip-induced switching of photochromic thiol functionalized terphenylthiazole-based diarylethene self-assembly on Au(111) has been investigated in ambient conditions. For such a purpose, we took advantage of the formation of highly ordered domains of opened-ring (1o) or closed-ring (1c) diarylethene isomers. We evidenced a STM-tip-induced switching for the 1o isomer characterized by a tip bias threshold of 1000 mV above which switching of all molecules of the ordered 1o domains occurs into the 1c isomer.
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