Cyano-Functional Group as an Anchoring Tool for Organic Small Molecules on Gold

We evidence the effect of the cyano-functional group in organic thin films investigating a δ4-substituted pentacene derivative, by using X-ray photoemission (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopies, together with atomic force microscopy. We have found that the presence of the cyano-functional group marks the electronic structure, the interface phenomena, and the film morphology in the CN-substituted pentacene deposited on Au(111) single crystals. This is due to the presence of the CN groups, which is known to have a strong chemical affinity toward gold. We propose the cyano-functional group as an efficient tool to chemically modify and functionalize gold surfaces or to anchor a variety of organic semiconductors on gold.