Study of Two Puzzled Questions on the Fullerene C_(70):A First-principles Study

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The cycloaddition reactions of NH to different bonds on C70 have been studied by the first-principles calculations.The results indicate that the reactivity of cycloaddition reactions is determined by the directional curvature,KD,and the larger binding energy of Eb on the bond C5-C’5 can be ascribed to the unique bond which can be treated as the shortest bond of(5.5)-SWCNT in the four [6,6] ring fusion bonds.This work also discloses that the energy gap of different spin states is decided by the electronic density,and that of the frontier obitals for the bond C5-C’5 is larger than the value for the C4-C’4 bond.Furthermore,the transition state investigation of the two bond addition reactions provides a reaction barrier of 11.10 kcal/mol for the NH cycloaddition to the C5-C’5 bond;whereas,the addition reaction on C4-C’4 is a spontaneous pathway.Herein,the dynamics effect illustrates the [2+1] cycloaddition reaction on the equatorial C5-C’5 bond to be unfavorable. The cycloaddition reactions of NH to different bonds on C70 have been studied by the first-principles calculations. The results indicate that the reactivity of cycloaddition reactions is determined by the directional curvature, KD, and the larger binding energy of Eb on the bond C5- C’5 can be ascribed to the unique bond which can be treated as the shortest bond of (5.5) -SWCNT in the four [6,6] ring fusion bonds.This work also discloses that the energy gap of different spin states is by the electronic density, and that of the frontier obitals for the bond C5-C’5 is larger than the value for the C4-C’4 bond.Furthermore, the transition state investigation of the two bond addition reactions provides a reaction barrier of 11.10 kcal / mol for the NH cycloaddition to the C5-C’5 bond; while, the addition reaction on C4-C’4 is a spontaneous pathway. Herein, the dynamics effect illustrates [2 + 1] cycloaddition reaction on the equatorial C5-C’5 bond to be unfavorable.
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