Pv. Lalitha et R. Ramaswamy, NEW SUBSTRATES IN THE FERROIN-CATALYZED BROMATE SYSTEM IN AQUEOUS-ORGANIC MIXED-MEDIA, International journal of chemical kinetics, 25(6), 1993, pp. 457-468
A large number of substrates have hitherto been employed in the Belous
ov-Zhabotinsky (B-Z) oscillatory system in pure aqueous medium. A syst
ematic study of aromatic bromate oscillators is limited by solubility
problem relating to the compounds and the brominated derivatives. The
use of aqueous-organic mixed media for the oscillatory study is found
to be highly useful for the study of water insoluble substances. A com
parative study of the oscillatory behavior of gallic acid as substrate
in pure aqueous as well as in a number of mixed media have been made
in order to ascertain the suitability of mixed media in oscillatory sy
stems. The alteration of oscillatory characteristics in the presence o
f organic solvent can be understood in terms of the Field-Koros-Noyes
(FKN) mechanism. The oscillatory behavior of seventeen new substrates
in the ferroin-catalyzed bromate system in 20% (v) acetonitrile is als
o presented and discussed in this communication. The reactivity of str
ucturally related substrates has been correlated to the structure in t
erms of the relevant oscillatory parameters. The use of aqueous-organi
c mixed media in oscillatory systems would enable the investigation of
new classes of substrates since getting them into the solution phase
would no longer be a limitation.