Abstract (EN):
Single-walled carbon nanotubes (SWNTs) have the ability to catalyze chemical reactions when they occur in their inner space. To date, no systematic investigation has considered the effect of chirality on the kinetics and molecular features of reacting systems. This study advances our understanding of this question by comparing the impact of different types of SWNTs, armchair (n,n), zigzag (n,0), and chiral (n,m), on the particular Menshutkin S(N)2 reaction between ammonia and chloromethane. The stationary points of the corresponding potential energy surfaces were obtained via the Density Functional Theory (DFT) with the hybrid functional M06-2X. In general, all of the SWNTs are able to reduce significantly the activation energy and the endothermicity of the reaction when compared to the values in the gas phase. For large diameters, all types of SWNTs converge to the limit values of these two energetic parameters, respectively, 28 and 21 kcal mol(-1), which correspond to the reaction over a graphene surface. However, as the diameters decrease, each type of SWNT shows a different potential well, with chiral (6,4) SWNT (diameter 6.8 angstrom) exhibiting the lowest energy barrier of 17.9 kcal mol(-1).
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
8