of symmetrically substituted derivatives, the, 13Cmr chemical shifts correlate with ΣσR0. This correlation is only observed in cases where the Cα—Cβ bond has no net polarity. Details of the thermal isomerization of those derivatives for which the possibility of cis and trans configurations exists are also reported. Trends in the Arrhenius parameters provide evidence for the biradical character of the
报道了广泛系列的 1,1,2,2-四芳基
环丙烷的合成和光谱表征。详细检查了取代基对 13Cmr 和 1Hmr
化学位移的影响。在一系列对称取代的衍
生物中,13Cmr
化学位移与 ΣσR0 相关。这种相关性仅在 Cα-Cβ 键没有净极性的情况下观察到。还报道了可能存在顺式和反式构型的那些衍
生物的热异构化的细节。阿伦尼乌斯参数的趋势为过渡态的双基特征提供了证据。讨论了支持过渡态双基特征的其他数据。