Maroz Andrej, Hermann Ralf, Naumov Sergej, Brede Ortwin
University of Leipzig, Interdisciplinary Group Time-Resolved Spectroscopy, Permoserstrasse 15, D-04303 Leipzig, Germany.
J Phys Chem A. 2005 Jun 2;109(21):4690-6. doi: 10.1021/jp0503056.
The electron transfer from aniline and its N-methyl as well as N-phenyl substituted derivatives (N-methylaniline, N,N-dimethylaniline, diphenylamine, triphenylamine) to parent solvent radical cations was studied by electron pulse radiolysis in n-butyl chloride solution. The ionization results in the case of aniline (ArNH2) and the secondary aromatic amines (Ar2NH, Ar(Me)NH) in the synchronous and direct formation of amine radical cations, as well as aminyl radicals, in comparable amounts. Subsequently, ArNH2*+ deprotonates in a delayed reaction with the present nucleophile Cl-, and forms further ArNH*. In contrast, tertiary aromatic amines such as triphenylamine and dimethylaniline yield primarily the corresponding amine radical cations Ar3N*+ or Ar(Me2)N*+, only. The persistent Ar3N*+ forms a charge transfer complex (dimer) with the parent amine molecule, whereas Ar(Me2)N*+ deprotonates to carbon-centered radicals Ar(Me)NCH2*.
通过电子脉冲辐解研究了在正丁基氯溶液中苯胺及其N - 甲基以及N - 苯基取代衍生物（N - 甲基苯胺、N，N - 二甲基苯胺、二苯胺、三苯胺）向母体溶剂自由基阳离子的电子转移。在苯胺（ArNH₂）和仲芳胺（Ar₂NH、Ar(Me)NH）的情况下，电离会同步且直接地以相当的量形成胺自由基阳离子以及氨基自由基。随后，ArNH₂⁺与存在的亲核试剂Cl⁻在延迟反应中去质子化，并进一步形成ArNH·。相比之下，叔芳胺如三苯胺和二甲基苯胺仅主要产生相应的胺自由基阳离子Ar₃N⁺或Ar(Me₂)N⁺。持久性的Ar₃N⁺与母体胺分子形成电荷转移络合物（二聚体），而Ar(Me₂)N⁺去质子化形成碳中心自由基Ar(Me)NCH₂·。
