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Titolo:
Radiation chemical oxidation of aniline derivatives
Autore:
Singh, TS; Gejji, SP; Rao, BSM; Mohan, H; Mittal, JP;
Indirizzi:
Univ Pune, Natl Ctr Free Rad Res, Dept Chem, Pune 411007, Maharashtra, India Univ Pune Pune Maharashtra India 411007 , Pune 411007, Maharashtra, India Bhabha Atom Res Ctr, Radiat Chem & Chem Dynam Div, Mumbai 400085, India Bhabha Atom Res Ctr Mumbai India 400085 Dynam Div, Mumbai 400085, India Indian Inst Sci, Jawaharlal Nehru Ctr Adv Sci Res, Bangalore 560064, Karnataka, India Indian Inst Sci Bangalore Karnataka India 560064 560064, Karnataka, India
Titolo Testata:
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
fascicolo: 7, , anno: 2001,
pagine: 1205 - 1211
SICI:
1472-779X(2001):7<1205:RCOOAD>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
AQUEOUS-SOLUTION; PULSE-RADIOLYSIS; OH RADICALS; HYDROXYCYCLOHEXADIENYL RADICALS; METHYLATED BENZENES; ELECTRON; HYDROXYLATION; REACTIVITY; SPECTRA; CATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Rao, BSM Univ Pune, Natl Ctr Free Rad Res, Dept Chem, Pune 411007, Maharashtra, India Univ Pune Pune Maharashtra India 411007 1007, Maharashtra, India
Citazione:
T.S. Singh et al., "Radiation chemical oxidation of aniline derivatives", J CHEM S P2, (7), 2001, pp. 1205-1211

Abstract

The reactions of (OH)-O-., O.- and N-3(.) with chloro- and hydroxy-anilines were studied by pulse radiolysis. The rates of the OH radical reaction are higher (k similar to 5x10(9) dm(3) mol(-1) s(-1)) than those found for the O.- and N-3(.) reactions (k similar to 2x10(9) dm(3) mol(-1) s(-1)). Neither the position of the substituent nor the introduction of an additional Cl to monochloroanilines has any significant effect on the rates of the (OH)-O-. reaction. The intermediates formed in all the aniline derivatives studied herein have lambda (max) values around 310-320 and 350-380 nm. The OH radical reacts both by addition and direct H abstraction giving rise to OH adducts (350-380 nm) and anilino radicals (310-320 nm). The extent of these two reactions depends on the position of the substituent, the former being more predominant in the meta than in the ortho and para isomers. The initially-formed OH adducts subsequently undergo dehydration, leading to anilino radicals in the case of chloroanilines and phenoxyl radicals with hydroxyanilines. The OH attack at the carbon bonded to Cl in all three monochloroanilines is not significant (less than or equal to 15%). Semi-empirical quantum calculations using the PM3 method were carried out to evaluate the possible sites of the OH radical attack. The charge distribution and the heats offormation data reveal that the (OH)-O-. attack extends over more than one carbon center. The relative stabilities of the isomeric OH adducts formed from the attack at the unsubstituted carbons of chloro- and hydroxy-anilinesare nearly the same, their respective heats of formation being approximately -70 and -230 kJ mol(-1).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/03/20 alle ore 14:14:22