School of Applied Chemistry and Department of Medical Education, Chung Shan Medical University, 402, Taichung, Taiwan,
J Mol Model. 2013 Oct;19(10):4387-94. doi: 10.1007/s00894-013-1957-y. Epub 2013 Aug 6.
In this study, we compare the dimerization of N,N'-diamidocarbene with that of N-heterocyclic carbene (NHC). Less interaction occurred between the filled lone pair of nitrogen and the unfilled lone pair of the carbenic center for a N,N'-diamdiocarbene than did in a saturated NHC because of the resonance between the lone pair of nitrogen and a carbonyl group. Therefore, a N,N'-diamidocarbene exhibits less singlet-triplet splitting. The less singlet-triplet splitting in a heterocyclic carbene containing nitrogen, the more exothermic the dimerization, which is consistent with the conclusion of Thiel et al. (Chem Phys Lett 217:11-16, 1994).
在这项研究中，我们比较了 N,N'-二氨基卡宾与 N-杂环卡宾（NHC）的二聚化。由于氮的孤对电子和卡宾中心的未填充孤对电子之间发生共振，因此 N,N'-二氨基卡宾中的孤对电子与羰基之间发生共振，与饱和 NHC 相比，发生的相互作用较少。因此，N,N'-二氨基卡宾表现出较小的单重态-三重态分裂。氮杂环卡宾中单重态-三重态分裂越小，二聚化越放热，这与 Thiel 等人的结论一致（Chem Phys Lett 217:11-16, 1994）。
