[reaction: see text] The temperature dependence of the dissociation of dimers formed from highly stabilized carbon-centered radicals has been examined. Analysis of the data yields the bond dissociation energy (BDE) for the central head-to-head C-C bond in these compounds. For example, for the dimer derived from 3-phenyl-2-coumaranone, BDE is 23.6 kcal/mol and the C-C bond length 1.596 A, a rather long
                                    [反应:见正文]研究了由高度稳定的以碳为中心的自由基形成的二聚体解离的温度依赖性。数据分析得出这些化合物中中心头对头CC键的键解离能(BDE)。例如,对于衍生自3-苯基-2-
香豆酮的二聚体,BDE为23.6 kcal / mol,CC键长度为1.596 A,这是sigma键的相当长的值。