Sensitized Photografting of Diazonium Salts by Visible Light.

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Sensitized Photografting of Diazonium Salts by Visible Light.

Visible irradiation of a gold surface dipped into a solution of diversely substituted aryldiazonium salts in the presence of a photosensitizer (Ru­(bipy)₃²⁺ or eosinY) leads to a modification of the surface by attached aryl groups. A grafted nanometer thick polyphenylene film is obtained. The reaction is extended to a polyvinylchloride (PVC) surface. The mechanism proposed for the formation of this film involves the formation of an aryl radical that reacts with the surface and then with the first grafted aryl group. The film is characterized by infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), water contact angles, and ellipsometry