Incorporation of butyl groups into chlorinated diamond surface carbons by organic reactions at ambient temperature
Hydrogenated diamond powder has been chlorinated by a radical reaction using sulfuryl chloride in chloroform at 50°C. The chlorinated diamond was then treated with n-, sec- and tert-butyllithium in tetrahydrofuran at 30°C for 4 h, and butyl groups were incorporated onto the surface. The modified diamond powder was characterized by diffuse reflectance IR Fourier-transformed (DRIFT) spectroscopy. The surface substituents were decomposed by flash pyrolysis in a nitrogen flow at temperatures between 255 and 1040°C and essentially all organic fragments were recovered. When the pyrolysis temperature was increased, the total amount of recovered carbons gradually approached a constant value. The fraction of butylated surface carbons to the total surface carbons was calculated based on pyrolysis products obtained at 1040°C and was 0.055 for n-butylation, 0.040 for sec-butylation and 0.047 for tert-butylation.