Radiation chemical formation of radical cations of halogenoalkanes and their electron spin resonance spectra and structure
作者:George W. Eastland、S. Paul Maj、Martyn C. R. Symons、Akinori Hasegawa、Christopher Glidewell、Michiro Hayashi、Toshio Wakabayashi
DOI:10.1039/p29840001439
日期:——
the formation of dimer radical cations, (RX)2+, again having the unpaired electron in a σ* orbital. In the particular case of t-butyl chloride, neither the parent cation, nor its complex with a solvent molecule were detected. Instead, a multiline spectrum was obtained which we assign to (Me2CCH2)+ cations weakly complexed with HCl. Theoretical calculations on the parent cations, their dimers, and adducts
将三氯氟甲烷中的氯,溴和碘代烷烃的稀溶液在77 K下暴露于60 Coγ射线,得到相应的阳离子。但是,对于RCI +和RBr +,该孔通过形成σ键与溶剂分子的一个氯原子共享,如[RCI [略图] CICFCI 2 ] +所示。对于烷基氯化物,两个氯核的超精细偶合常数几乎相等。(RBr)+加合物显示的esr谱图由溴的主要四元组裂解和氯的其他四元组裂解组成。对于碘阳离子,没有获得明确的证据表明存在这种键合,并且碘离子的变化非常大。由明显的自旋轨道耦合产生的g值。对于更浓缩的溶液,esr谱图显示了由于与两个等效卤素原子核偶联而产生的septet超细图谱,这表明形成了二聚体自由基阳离子(RX)2 +,该金属在σ*轨道中也具有未配对的电子。在叔丁基氯的特定情况下,既未检测到母体阳离子,也未检测到其与溶剂分子的络合物。相反,获得了多谱线光谱,我们将其分配给与HCl弱络合的(Me 2 C CH 2)+阳离子。对母体阳离子,其二聚体和CFCl