PI -PI -INTERACTIONS IN PENTACYCLO-8.2. 1.1.2,51.4,718,11HEXADECA-1,7-DIENE
PI -PI -INTERACTIONS IN PENTACYCLO-8.2. 1.1.2,51.4,718,11HEXADECA-1,7-DIENE
复制标题
五环-8.2 中的 PI-PI-相互作用。
DOI：
10.1021/jo972051t
复制
发表时间：
1998
影响因子：
3.6
通讯作者：
S. Vázquez
中科院分区：
文献类型：
--
作者：
H. Lange;W. Schäfer;R. Gleiter;P. Camps;S. Vázquez
结论由于π +和π r与CrC σ键的相互作用都很强，因此通过空间分裂产生的大分裂得以保持，与4a和4b的PE谱相反，3的PE谱仅显示π +和π r产生的谱带之间的微小分裂（见图4）。计算3中的TS分裂5与4a中的TS分裂相当。然而，3中的TS分裂仅通过π +与σ骨架的相互作用来补偿，而π r在σ框架中没有伙伴可以相互作用。因此，与4中的情况不同，在4中，σ键与π +和π r相互作用，使得它们的TS分裂得以维持，在3中，TB相互作用仅使π +不稳定，几乎精确地补偿了π +和π r之间的TS分裂，导致PE光谱在外观上与4a和4b非常不同。
ConclusionSince both π+ and πr interact strongly with the CrC σ bonds, the large splitting due to the through-space splitting is maintained.In contrast to the PE spectra of 4a and 4b that of 3 shows only a minute splitting between the bands arising from π+ and πr (see Figure 4). The TS splitting in 3 was calculated5 to be comparable to that in 4a. However, the TS splitting in 3 is compensated for by interaction of only π+ with the σ skeleton, while πr has no partner in the σ frame to interact with. Consequently, unlike the case in 4, where the σ bonds interact with both π+ and πr so that their TS splitting is maintained, in 3 the destabilization of only π+ by TB interactions almost exactly compensates for the TS splitting between π+ and πr leading to a PE spectrum that is very different in appearance from that of 4a and 4b.