23337-93-1Relevant academic research and scientific papers
Combination and Disproportionation Reactions of the Radical
Goergenyi, Miklos,Seres, Laszlo
, p. 1827 - 1830 (2007/10/02)
The radical (1) was produced in the di-tert-butyl peroxide-initiated and thermal decompositions of azoethane.Self-combination of 1 takes place almost exclusively at the carbon radical centre (1C).The disproportionation: combination ratio Δ(C2H5., 1N) ca. 0.38 (Δ = kd/kc) and the rate constant ratio kd(CH3., 1N)/kc(CH3., 1C) = 0.15 +/- 0.03.The cross-combination ratio Φ(CH3., 1C) = 1.38 +/- 0.11, which is lower than the cross-reaction ration Φ*(CH3., 1) ca. 2.5.
Kinetic Effects of an Unusually Large Neutral to Radical Cation Geometry Change. Slow Electron-Transfer Reactions between Alkylhydrazines
Nelsen, Stephen F.,Rumack, Daniel T.,Meot-Ner (Mautner), Michael
, p. 1373 - 1379 (2007/10/02)
High pressure mass spectrometry was used to measure the kinetics for electron transfer between 54 pairs of tetraalkylhydrazines containing acyclic and f-ve- to seven-membered cyclic and bicyclic rings.Rate constants for electron transfer vary between 18 and 0.03 x 10-11 cm3molecule-1s-1 at 550 K.Variable-temeprature mesuremeants were made on five pairs over a 77-120 deg range.The (Me2N)2(1+), (EtMeN2)2 pair gave Ea=2.7 kcal/mol.The association energy for (Me2N)2 was measured at ΔH0=-13.0 kcal/mol near room temperature.These data are combined to estimate an energy separation of about 15.7 kcal/mol between associated (Me2N)2(1+)/(EtMeN)2 dimer complex and the transition state for electron transfer.The observed Bronsted α value of about 0.5 suggests a large barrier to electron transfer, and the kinetics suggests that the components largely retain their original structures in the associated complex, but that significant distortion is required to reach the transition-state geometry.The effect of alkyl group changes on the electron-transfer rate and comparison of these data with solution experiments are discussed.
