AMINOLYSIS OF ARYL DITHIO-2-THIOPHENATES AND DITHIO-2-FUROATES IN ACETONITRILE

Citation
Hk. Oh et al., AMINOLYSIS OF ARYL DITHIO-2-THIOPHENATES AND DITHIO-2-FUROATES IN ACETONITRILE, International journal of chemical kinetics, 30(11), 1998, pp. 849-857
Citations number
22
Categorie Soggetti
Chemistry Physical
ISSN journal
05388066
Volume
30
Issue
11
Year of publication
1998
Pages
849 - 857
Database
ISI
SICI code
0538-8066(1998)30:11<849:AOADAD>2.0.ZU;2-7
Abstract
The aminolyses of the title substrates with anilines and benzylamines are investigated in acetonitrile. A clean second-order kinetics is obt ained with a first-order rate law in the amine concentration, which is uncomplicated by the fast proton transfer step. The large magnitude o f rho(z) (rho(1g)) as well as rho(x) (rho(nuc)) together with relative ly large positive p(xz) values is consistent with a stepwise mechanism in which thiophenolate ion expulsion from the intermediate is rate li miting. For the reactions of aryl dithio-2-thiophenates with benzylami nes the magnitude of rho(x) and rho(z) values is relatively smaller su ggesting that both the addition and expulsion of thiophenolate are par tially rate determining. Relatively large secondary kinetic isotope ef fects, k(H)/k(D) greater than or equal to 1.7, with deuterated nucleop hiles, support involvement a concurrent proton transfer to the departi ng thiophenolate ion in the transition state. (C) 1998 John Wiley & So ns, Inc.