Comprehensive theoretical study of the phenyl azide addition onto armchair (۵,۵) single wall carbon nanotube

چکیده مقاله

To gain insight into the activation energies and reaction pathways of the chemical functionalization of armchair (5,5) single wall carbon nanotube (SWCNT), calculations have been carried out for the 1,3- dipolar cycloaddition of phenyl azide to armchair SWCNT (C140H20) and subsequent steps using ONIOM(B3LYP/6-31+G(d):AM1) method. We investigated two original states; 1,3-dipolar cycloaddition was done onto two various types of C–C bonds at the end and mid-wall of SWCNT; ‘‘circumferential” and ‘‘axial”. Results showed that for end-wall of armchair (5,5) SWCNT, the energy barrier height of the 1,3-dipolar cycloaddition process on the axial site is predicted to be 11.43 kcal mol1 higher than that of the concerted 1,3-dipolar cycloaddition on the circumferential position. Also, for mid-wall, first step of the 1,3-dipolar cycloaddition of phenyl azide onto the circumferential position has energy barrier equal to 31.56 kcal mol1, that is 4.88 kcal mol1 higher than that of the circumferential position of the end- wall of SWCNT. The 1,3-dipolar cycloaddition of phenyl azide onto the axial position of mid site of SWCNT was not done and related triazoline structure was not optimized. Our 2-layered ONIOM (B3LYP/6-31+G(d):AM1) calculations reveal that the 1,3-dipolar cycloaddition of phenyl azide onto the sidewalls of a (5,5) SWCNT is site-selective and facile on the circumferential C–C bond.