On the reaction of FNO2 with CH3, tert-butyl, and C13H21

Theoretical studies are reported for the reaction of FNO2 with the radicals CH3, tert-butyl, and C13H21, Which are templates for the radical site of a hydrogenated diamond (111) surface. All structures are fully optimized using density functional theory based on the B3LYP functional. Calibration calculations are performed for CH3 + FNO2 using the coupled cluster approach, the internally contracted multireference configuration interaction method, and second-order perturbation theory based upon the complete-active-space SCF reference wave function. These calibration calculations support the B3LYP approach for the calculation of bond energies but show that the B3LYP barrier is too low. Combining the calibration calculations with the larger clusters yields our best estimate of a barrier of about 10 kcal/mol for the reaction of FNO2 with a radical site on hydrogenated diamond (111).