Acta Phys. -Chim. Sin. ›› 2008, Vol. 24 ›› Issue (10): 1811-1816.doi: 10.1016/S1872-1508(08)60074-1

• ARTICLE • Previous Articles     Next Articles

Regioselectivity of 1,3-Butadiene Diels-Alder Cycloaddition to C59XH(X=N, B)

LIANG Yun-Xiao, SHANG Zhen-Feng, XU Xiu-Fang, ZHAO Xue-Zhuang   

  1. State Key Laboratory Base of Novel Functional Materials and Preparation Science, College of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, Zhejiang Province, P. R. China; Department of Chemistry, Nankai University, Tianjin 300071, P. R. China
  • Received:2008-03-31 Revised:2008-07-02 Published:2008-10-08
  • Contact: LIANG Yun-Xiao

Abstract: The regioselectivity of Diels-Alder cycloaddition of 1,3-butadiene to C59XH (X=N, B) has been studied theoretically by means of the semiempirical AM1 and DFT (B3LYP/6-31G*) methods. The mechanisms of the cycloaddition on some selected 6—6 bonds of C59XH (X=N, B) have been analyzed. For C59NH, the activation energies become lower with the addition site increasingly farther fromthe N atom; however, they are all higher than that of the reaction of 1,3-butadiene with C60. In contrast to C59NH, for the cycloaddition to C59BH, the activation energies corresponding to 2,12/r-and 2,12/f-transition states, in which the addition sites are the nearest ones to the B atom, are the lowest ones,and are lower than that of the reaction of 1,3-butadiene with C60 by over 18 kJ·mol-1, and the products corresponding to these two transition states are the most stable ones. The different electronic natures ofNandB atoms results in different effects on the Diels-Alder reactions of 1,3-butadiene with C59NH and C59BH; the former makes the reactivity of C59NH reduced and the latter makes the reactivity of C59BH enhanced, relative to that of C60.

Key words: C59XH(X=N, B), Diels-Alder cycloaddition, Regioselectivity, AM1, DFT