Amines and thiols on diamond surfaces

Photochemical reactions have proven to be mild, selective, and versatile methods for modifying diamond. The surfaces of hydrogenated diamond powders, films and single crystals were photochemically modified to produce diamond terminated with simple amines and thiols. The amines and thiols were prepared via a chlorinated diamond intermediate. The thiolated surface was also prepared directly from the hydrogenated diamond. The modified diamond surfaces were spectroscopically characterized using diffuse-reflectance infrared spectroscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. Changes in the electron work function of the diamond surfaces upon modification were determined using a Kelvin probe. Sessile-drop contact angle measurements were used to determine relative surface hydrophilicity.