自由基C_(59)N及双体(C_(59)N)_2的理论研究

Theoretical Studies on Radical C_(59)N and Its Dimer (C_(59)N)_2

用INDO系列方法对自由基C_(59)N及双体(C_(59)N)_2进行了理论研究,结果表明:N的掺入使C_(60)笼发生畸变,N向笼外突出,碳氮6-6键上的C自旋密度较大,两C_(59)N自由基在这个碳上以C—C单键连接形成双体为C_(2h),C_(2v).对称性.其中C_(2v)构型更稳定,且N与附近的三个碳均以单键连接.理论计算的电子光谱与实验吻合较好.(C_(59)N)_2易分解为单体C_(59)N.

Computation on radical C59N dimer (C59N)2 by INDO series methods suggests that the introduction of N atom into C60 distorts the cage with the N atom stretching out from the cage, the carbon in the 6 - 6 bond of C and N has large electron density, where two radicals bind to form dimer (C59N)2 with C2v and C2h symmetry. The C2v isomer is more stable than the C2h and the N atom binds with the connected carbons by single bond. The calculated electronic spectrum is consistent well with that of experiment. The dimer (C59N)2 readily dissociates to the monomer.