CAJ | 학술논문

应用半经验的AMI和密度泛函B3LYP/6-31G*方法对1,3-丁二烯与C59XH(X=N,B)Diels-Alder环加成反应的区域选择性进行理论研究,选择一些有代表性的C59XH(X=N,B)的6-16键探讨环加成反应的机理.1,3-丁二烯与C59NH进行的Diels-Alder反应,随着加成位置远离C59NH的N原子,活化能越来越低,但都比1,3-丁二烯与C60相应反应的活化能高.与此相反,对于1,3-丁二烯与C59BH进行的环加成反应.加成位置最靠近B原子的2,12/r-和2,12/f-过渡态的势垒最低,并且比1,3-丁二烯与C60进行环加成反应的活化能约低18 kJ·mol-1,其产物也是热力学最稳定的.与C60相应的反应相比,C59NH和C59BH中N和B原子不同的电子性质对其邻位双键进行Diels-Alder环加成反应的活性产生了不同影响,前者使反应活性降低,后者使反应活性增强.
응용반경험적AMI화밀도범함B3LYP/6-31G*방법대1,3-정이희여C59XH(X=N,B)Diels-Alder배가성반응적구역선택성진행이론연구,선택일사유대표성적C59XH(X=N,B)적6-16건탐토배가성반응적궤리.1,3-정이희여C59NH진행적Diels-Alder반응,수착가성위치원리C59NH적N원자,활화능월래월저,단도비1,3-정이희여C60상응반응적활화능고.여차상반,대우1,3-정이희여C59BH진행적배가성반응.가성위치최고근B원자적2,12/r-화2,12/f-과도태적세루최저,병차비1,3-정이희여C60진행배가성반응적활화능약저18 kJ·mol-1,기산물야시열역학최은정적.여C60상응적반응상비,C59NH화C59BH중N화B원자불동적전자성질대기린위쌍건진행Diels-Alder배가성반응적활성산생료불동영향,전자사반응활성강저,후자사반응활성증강.
The regioselectivity of Diels-Alder cycloaddition of 1,3-butadiene to C59XH(X=N,B) has been studied theoretically by means of the semiempidcal AM1 and DFr (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 from the N atom; however, they are all higher than that of the reaction of 1,3-butadiene with C60 In contrast to C50NH, 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 18kJ·mol-1, and the products corresponding to these two transition states are the most stable ones. The different electronic natures of N and B atoms results in different effects on the Diels-Alder reactions of 1,3-butadiene with C50NH and C59BH; the former makes the reactivity of C59NH reduced and the latter makes the reactivity of C59BH enhanced, relative to that of C60.