Pulse-radiolysis studies on 4-pyridinemethanol and 4-pyridinecarboxaldehyde in aqueous solutions: dimer radical anion formation in the case of 4-pyridinecarboxaldehyde |
| |
Authors: | DB Naik GR Dey AD Belapurkar K Kishore |
| |
Institution: | (1) Radiation Biology &; Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India;(2) Radiation &; Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India; |
| |
Abstract: | Reactions of e
aq
–
, H atom and OH radicals with 4-pyridinemethanol (4-PM) and 4-pyridinecarboxaldehyde (4-PCA) have been studied at various pH values using the pulse radiolysis technique. Reaction of e
aq
–
with 4-PM and 4-PCA leads to the formation of pyridinyl and ketyl radicals of 4-PM and 4-PCA, respectively. Ketyl radicals formed from 4-PCA react with the parent molecule to give a dimeric radical species. At pH 7, the equilibrium constant for the dimer formation was determined to be 13 500 M-1. At pH 13 also dimer radical formation was observed. Reaction of e
aq
–
with 4-PM was found to give highly reducing pyridinyl radicals. Reaction of OH radicals with 4-PM gives a mixture of species,viz., OH adducts and radicals formed by H-atom abstraction from the –CH2OH moiety. Radicals formed by H-atom abstraction reaction from 4-PM were found to be reducing in nature. O – radicals were found to react with 4-PM exclusively by H-abstraction pathway. |
| |
Keywords: | 4-PYRIDINEMETHANOL 4-PYRIDINECARBOXALDEHYDE PULSE RADIOLYSIS DIMER RADICAL ANION |
本文献已被 SpringerLink 等数据库收录! |
|