Weakly Bound Carbon-Carbon Bonds in Acenaphthene Derivatives and Hexaphenylethane
Weakly Bound Carbon-Carbon Bonds in Acenaphthene Derivatives and Hexaphenylethane
复制标题
DOI：
10.1021/jp909662m
复制
发表时间：
2010-01-21
影响因子：
2.9
通讯作者：
Wang, Hai
中科院分区：
文献类型：
--
作者：
Dames, Enoch;Sirjean, Baptiste;Wang, Hai
一类苊衍生物被证明含有弱的中心碳-碳键，其可以在高温下或甚至在环境条件下容易地裂解以产生持久的自由双自由基。为了证明弱C-C键强度，在几个理论水平上对母体分子和由C-C键断裂产生的双自由基进行了密度泛函理论计算。为了评估计算的准确性，选择六苯乙烷作为模型化合物，因为它与这里研究的分子相似，具有很好的共振稳定性，并且在化学界有着悠久的历史。在M06-2X/6-31+G（d，p）理论水平上，用等键反应和计算相结合的方法测定了六苯乙烷的C-C键离解能为11.3 +/- 1.4 kcal/mol。这里提出的分子类型被认为是碳氢化合物燃烧中形成的年轻和成熟烟灰中自由基自然存在的强烈可能性。
A class of acenaphthene derivatives is shown to contain weak central carbon-carbon bonds that may be easily cleaved at high temperatures or even at ambient conditions to yield persistent free diradicals. To demonstrate the weak C-C bond strength, density functional theory calculations were carried out at several levels of theory for both the parent molecules and the diradicals resulting from the C-C bond cleavage. To assess the accuracy of the calculations, hexaphenylethane was chosen as a model compound due to its similarity with the molecules studied here, its great resonance stabilization, and long-standing history within the chemistry community. The C-C bond dissociation energy of hexaphenylethane was determined to be 11.3 +/- 1.4 kcal/mol using a combination of isodesmic reactions and calculations at the M06-2X/6-31+G(d,p) level of theory. The types of molecules presented here are proposed as strong possibilities for the natural existence of free radicals ill Young and Mature Soot formed in hydrocarbon combustion.