Aliphatic alcohols, trapped electron

In this chapter, the recent progress in the understanding of the nature and dynamics of excess (solvated) electrons in molecular fluids composed of polar molecules with no electron affinity (EA), such as liquid water (hydrated electron, and aliphatic alcohols, is examined. Our group has recently reviewed the literature on solvated electron in liquefied ammonia and saturated hydrocarbons and we refer the reader to these publications for an introduction to the excess electron states in such liquids. We narrowed this review to bulk neat liquids and (to a much lesser degree) large water anion clusters in the gas phase that serve as useful reference systems for solvated electrons in the bulk. The excess electrons trapped by supramolecular structures (including single macrocycle molecules ), such as clusters of polar molecules and water pools of reverse micelles in nonpolar liquids and complexes of the electrons with cations in concentrated salt solutions, are examined elsewhere. 

The trapped electron in the aliphatic alcohols is characterized by optical absorption in the visible part of the spectrum. Its absorption... 

The spin trapping of NO as aminoxyl radicals (ARs) Rj-NO -R was observed by electron spin resonance (ESR) spectroscopy in various radical reactions. For example, such ARs are formed in the course of the photodecomposition of 2,2 -azobisisobutyronitrile (AIBN) in aliphatic alcohols (methanol, ethanol, 2-propanol) [15]. In this case, Rj is the radical NhC-CICHj) from AIBN, and R is derived from alcohol molecules as a result of a hydrogen atom abstraction by Rj. 

The radical anion of molecular oxygen (O ) has been prepared and trapped in a range of alcohols, water and benzene but not in aliphatic hydrocarbons (Bennett et al., 1968a). In contrast to COg the e.s.r. spectrum shows that 0 interacts strongly with its immediate environment. This interaction which alters the separation of the upper molecular orbitals of the anion is strongly dependent on the nature of the matrix. Previously, the Oj" radical ion has been stabilized only in ionic materials such as the alkali halides thus it is of particular interest to find that this anion can be trapped successfully in a non-polar matrix (benzene). There is some evidence (Evans, 1961), from optical spectroscopic studies that molecular oxygen can form a weak charge transfer complex with the 77-electron system in benzene and it seems probable that O2 is stabilized in benzene by the formation of a similar complex. 

In reaction of aliphatic nitro compounds with alkyl radicals 6 7 generated from ethers or alcohols aminyloxides 69b could be detected79. Moreover dialkylaminyl-oxides 74b are formed, 67 being trapped from the corresponding nitroso compound. Reduction of nitro compound to nitroso compound probably occurs by electron transfer from alkyl radical 67 to nitro compound, subsequent dissociation of the resulting complex 68b giving nitro anion radical which finally disproportionates. 

Decarbo>ylation of a-(oo-carbo grallg l)-p-ketoesters (44) by photoinduced electron transfer leads to one-carbon expanded y-ketoesters and bicyclic alcohols.Irradiation of aqueous alkaline solutions of 2-aryloxy- or 2-aryl-acetic acids at 300 nm in the presence of Selectfluor results in fluorodecarboxylation. Decarbojq lation of aliphatic carboxylic acids or iV-(t-buto)ycarbonyl)amino acids by means of oxidative electron transfer using catalytic amounts of photosensitisers leads to free radicals that can by trapped by actylonitrile. ... 

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