On-Surface Formation of Cyano-Vinylene Linked Chains by Knoevenagel Condensation

Chemistry. 2021 Dec 9;27(69):17336-17340. doi: 10.1002/chem.202103094. Epub 2021 Oct 21.

Abstract

The rapid development of on-surface synthesis provides a unique approach toward the formation of carbon-based nanostructures with designed properties. Herein, we present the on-surface formation of CN-substituted phenylene vinylene chains on the Au(111) surface, thermally induced by annealing the substrate stepwise at temperatures between 220 °C and 240 °C. The reaction is investigated by scanning tunneling microscopy and density functional theory. Supported by the calculated reaction pathway, we assign the observed chain formation to a Knoevenagel condensation between an aldehyde and a methylene nitrile substituent.

Keywords: Knoevenagel condensation; density functional calculations; on-surface chemistry; scanning probe microscopy.