Electron Localization and Radiation Chemistry of Amides

Abstract

Alkylamides (such as N,N'-dimethylformamide, N,N'-diethylformamide, and N,N'-dimethylacetamide) are aprotic solvents that are widely used in organic synthesis. These polar molecules have no electron affinity, and it is believed that irradiated liquid and solid amides stabilize excess electrons as cavity-type species analogous to hydrated and ammoniated electrons. In this study, we use isotope substitution and EPR spectroscopy to demonstrate that, in frozen amides, the suspected "cavity electron" is, in fact, a solvent-stabilized monomer anion. Our observations call into question other attributions of such features in the literature, both in low temperature solids and room temperature liquids. We also provide a general scheme describing amide radiolysis, as the related amides are used as metal ion extracting agents in nuclear separations.

Efficient solvent system containing malonamides in room temperature ionic liquids: actinide extraction, fluorescence and radiolytic degradation studies

“…12). 41,42 But the radiation stability is found to be relatively inferior than that in n-dodecane. This suggests that the aromatic cation imidazolium moiety was unable to protect the damage by alkyl chain radical formations.…”

“…39 Recent reports on the degradation behavior of amides in RTILs suggested the radical mechanism for the degradation of different formamides and N,N,N′,N′-tetra alkyl-substituted diglycolamides like TODGA. 41,42 But for DIAMEX solvents such as DMDBTDMA and DMDOHEMA in RTIL medium no such systematic study was done before. In this context, irradiated samples were subjected for GC analysis to identify the degradation products of malonamides and of RTIL.…”

CdS Quantum Dots as Potent Photoreductants for Organic Chemistry Enabled by Auger Recombination

“…Potential role of DMPU solvent. The inferior performance of amide solvents and other aprotic solvents relative to DMPU led us to consider that a solvent reduction mechanism could be operative (e.g., formation of DMPU •or DMA •-, species that have been observed when alkali metals are dissolved in these solvents) 131,132 and that this could impose a leveling effect on the potentials accessible by the QDs/TAEA system. The different performance would arise from differences in the reducing power of the respective radical anions because ureas like DMPU are harder to reduce to the corresponding radical anion than other carbonyl derivatives.…”

Structural, magnetic and optical properties of an FeIIIdimer bridged by the meridional planar divergent N,N′-bis(salicyl)hydrazide and its photo- and electro-chemistry in solution

“…The multiplicity of three, the g-values of 2.003, close to the free electron resonance, and the hyperfine constant A = 20 G are consistent with those of a free radical of DMF. 40 Thus a mechanism of photoreduction involving this radical is strongly possible.…”