Preparation and ESR characterization of polyalkyl-s-indacenyl anion-radicals from polyalkyl-1,5-dilithio-s-indacenes
作者:C. Adams、J. Araneda、C. Morales、I. Chavez、J.M. Manriquez、D. Mac-Leod Carey、N. Katir、A. Castel、P. Rivière、M. Rivière-Baudet、M. Dahrouch、N. Gatica
DOI:10.1016/j.ica.2010.10.002
日期:2011.1
Polyalkyl-(or chloropolyalkyl)-s-indacenyl anion radicals were obtained from the organodilithium derivatives of the corresponding substituted-1,5-dihydro-s-indacenes by three different methods: (i) UV photolysis, (ii) oxidation by a ferrocenium salt, (iii) single electron transfer reaction from an electron rich olefin. The last reaction (iii) involves transient formation of an unstable polyalkyl-lithio-s-indacenyl imidazolidinium salt. The same salt, obtained by another way by reacting 1,3-dimethylimidazolidinium chloride with the polyalkyl-1,5-dilithio-s-indacene, also leads to the corresponding lithium polyalkyl-s-indacenyl anion radical. All lithium polyalkyl-s-indacenyl anion radicals studied were characterized from their ESR spectra. They present a characteristic symmetrical spin distribution. On the contrary a Rhodium-COD polyalkyl-s-indacene radical presents a non symmetrical spin distribution. (C) 2010 Elsevier B.V. All rights reserved.