One-electron reduced species

In a report by Hole et al, single crystals of 2 -deoxycytidine hydrochloride were investigated at 10 K using K-band (24 GHz) EPR, ENDOR and FSE spectroscopy.10 In this work, nine different radical products were identified and characterized. Three are one-electron reduced species (8,9 and 10), one each is formed by net hydrogen addition to C5 (11) and C6 (12). The remaining four are formed by net hydrogen atom loss from the 2 -deoxyribose moiety three of these (13—15) could be identified. 

Molecular modeling calculations were conducted on the methyl viologen derivative 8 and methyl viologen (MVZ+) to generate the dihedral angles for the dicationic (fully oxidized) and monocationic (one-electron reduced) species <2005TL7291>. 

Reactions of basic lithium compounds LiR or LiER with halides [19,37,59], pseudohalides [62] or unsaturated acceptors [63-65] were frequently reported to involve SET steps. The strongly basic character of such lithium compounds may, however, cause the observation of apparent one electron-reduced species such as ketyls or semiquinones via deprotonation of hydrolysis products and ensuing comproportionation reactions (Eq. (9)) [58]. 

In the following sections, the reduction potential and the electrochemical stability of the one-electron reduced species (semiquinone intermediate) are discussed using MO theory. 

The one-electron reduced species (semiquinone intermediates) undergo disproportionation reaction [Eq. (17)]. 

As demonstrated above, the interaction of Bronsted and Lewis acids with an electron acceptor or the one-electron reduced species results in remarkable acceleration of the rate of electron transfer from an electron donor to the acceptor due to the... 

The oxygen consumed during phagocytosis is utilized by a unique enzyme system termed the respiratory burst oxidase or NADPH oxidase. The oxidase generates superoxide anion (Oj), a one-electron reduced species, driven by intracellular NADPH,... 

Examples of tetranuclear adamantane-shaped complexes (Type III) are [Mn4 06(bpea)4] + and its corresponding one-electron reduced species, while cubane cores (Type IV) are found in [Mn2 Mn2 04(02PPh2)6] and its one-electron reduced species. A large family of tetranuclear clusters is... 

M. Hoshino, S. Konishi, and M. Imamura, Solvent Effects on Optical and ESR Spectra of One-Electron Reduced Species of Cobalt(III) and Manganese(III) Tetraphenylporphyrins Produced by 7-Radiolysis at 77 K, Bull. Chem. Soc. Jpn., 57... 

Reduction of Q to Q in acetonitrile solution, however, would not be useful to switch on the luminescence of 10. In the one-electron reduced species, in fact, the luminescent excited state of Ru(bpy)3 + would be quenched by a very fast electron transfer process (AG —1.3 V) from the reduced quinone (Fig. 13). 

The CO2 reduction catalyzed by non-porphyrinic tetraaza macrocyclic complexes of Co(II) and Ni(II) yields CO and formic acid as main reduction products together with H2 as a by-product. The commonly accepted mechanism involves the reduction of the metal center M(II)L to form the one-electron-reduced species M(I)L followed by the direct reaction with CO2 to form an intermediate M(III)C02L, which is further pro-tonated and reduced to form CO and water and recover the starting form of the catalyst (Fig. 1). 

The IR spectra obtained in N2-saturated solution (Figure 1 Id and e) are similar to those recorded in CO-saturated solution (Figure 1 lb and c), but the eonversion rate of 15 to 15B as given at 2014 cm" in N2-saturated solution is faster than that reeorded in CO-saturated solution. We conclude either additional CO impedes the formation of one-electron reduced species or CO reacts with the transient intermediate to inhibit the efficient conversion into 15B. 

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