24344-83-0Relevant academic research and scientific papers
The return of the succinimidyl radical
Merenyi, Gabor,Lind, Johan,Eberson, Lennart
, p. 62 - 66 (2007/10/03)
The aqueous kinetics of the succinimidyl radical, S., has been re-examined in the presence of oxidizable substrates and oxygen. The results indicate a rapid equilibrium between S. and its ring-opened analogue, the β-(isocyanato-carbonyl)ethyl radical, PI.. The equilibrium constant K1 is ca. 10, with k1 ≈ 107 s-1 and k-1 ≈ 106 s-1. The glutarimidyl radical, G., was produced by one-electron reduction of N-chloroglutarimide, GCl. The rate constants of several oxidation and hydrogen abstraction reactions with S. and G. have been determined. Furthermore, halogen abstraction reactions from haloimides by some selected alkyl radicals were also scrutinised. Most striking is the finding that the 2-cyanoethyl radical abstracts Br from SBr ca. 25 times slower than does the ethyl radical. This demonstrates a strong β-effect and rationalises a relatively slow Br abstraction rate by PI. from SBr. While the closure rate of the PI' radical appears to be solvent-insensitive, the ring opening rate of S., k1, is estimated to be ca. 100 times faster in, e.g., CH2Cl2 than in water. This suggests hydrogen-bonded stabilisation of S.. Acta Chemica Scandinavica 1998.
One-Electron Reduction Potential and Ring Opening of the Succinimidyl Radical in Water
Lind, Johan,Jonsson, Mats,Eriksen, Trygve E.,Merenyi, Gabor,Eberson, Lennart
, p. 1610 - 1614 (2007/10/02)
By means of pulse radiolysis in water, N-chlorosuccinimide (SCl) was reduced in a one-electron step to yield the succinimidyl radicals, S*, via the intermediacy of the radical anion, SCl*-.The rate of ring opening of S* was measured to be 8 x 104 s-1.By equilibrium with Cl2*-/2Cl-, the one-electron reduction potential of S* was determined to be 2.22 +/- 0.02 V vs NHE.From this value and other data, the N-H bond strength in succinimide was calculated to be 118 +/- 3 kcal/mol.
Reaction of phenylchlorocarbene and diphenylcarbene with the carbon-chlorine bond: Kinetics and mechanisms
Jones, Michelle B.,Maloney, Vincent M.,Platz, Matthew S.
, p. 2163 - 2169 (2007/10/02)
The reactions of phenylchlorocarbene (PCC) and diphenylcarbene (DPC) with carbon-chlorine bonds were investigated by laser flash photolysis techniques, product studies, and electrochemical methods. The data with both carbenes are consistent with a polar chlorine atom transfer to form radical pairs. The PCC reaction can be thought of as an inner sphere electron transfer from the carbene to the carbon-halogen bond in which there is partial carbon-halogen bond formation in the transition state. The transition state is thought to involve a crossing between closed- and open-shell singlet surfaces. The data obtained in the reaction of DPC with chlorine donors resembles the data obtained with PCC but is more difficult to interpret because the multiplicity of the state reacting with the C-Cl bond is unclear.
