Maclean Micheal J, Eichinger Peter C H, Wang Tianfang, Fitzgerald Mark, Bowie John H
Department of Chemistry, The University of Adelaide, South Australia 5005.
J Phys Chem A. 2008 Dec 11;112(49):12714-20. doi: 10.1021/jp807403s.
Calculations at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-31+G(d) level of theory have shown that cyclization of both the ground state triplet and the corresponding singlet state of CCCSi may rearrange to give cyclic isomers which upon ring opening may reform linear C(3)Si isomers in which the carbon atoms are scrambled. The cyclization processes are energetically favorable with barriers to the transition states from 13 to 16 kcal mol(-1). This should be contrasted with the analogous process of triplet CCCC to triplet rhombic C(4), which requires an excess energy of 25.8 kcal mol(-1). A similar cyclization of doublet CCCP requires 50.4 kcal mol(-1) of excess energy; this should be contrasted with the same process for CCCN, which requires 54.7 kcal mol(-1) to effect cyclization.
在CCSD(T)/aug-cc-pVDZ//B3LYP/6-31+G(d)理论水平下的计算表明，CCCSi基态三线态和相应单重态的环化反应可能会重排生成环状异构体，这些异构体在开环后可能会重新形成碳原子发生混乱的线性C(3)Si异构体。环化过程在能量上是有利的，过渡态的能垒为13至16千卡/摩尔(-1)。这应与三重态CCCC转化为三重态菱形C(4)的类似过程形成对比，后者需要25.8千卡/摩尔(-1)的多余能量。二重态CCCP的类似环化反应需要50.4千卡/摩尔(-1)的多余能量；这应与CCCN的相同过程形成对比，后者环化需要54.7千卡/摩尔(-1)。
