Detail of "15416-77-0"

Reference

Kinetics of decomposition of o-benzoquinones in an aqueous medium

Kinetics of decomposition of o-benzoquinones in an aqueous medium. Suslov, S. N.; Stom, D. I. (Nauchno-Issled. Inst. Biol., Irkutsk, USSR). Gidrokhim. Mater., 69, 69-73 (Russian) 1977. CODEN: GKMAAS. DOCUMENT TYPE: Journal CA Section: 60 (Sewage and Wastes) Section cross-reference(s): 67 The macrokinetic equation for the title reaction was derived: dx/dt = 2k(a-x)(b + x/2), where x, t, k, a, and b were the concn. of the reacting quinone, reaction time, rate const. of the 1st reaction step involving the hydration of the o-quinone into trioxyderivs., the active concn. of o-quinone, and the active concn. of polyphenol, resp. The agreement of the equation with exptl. data was shown. Only o-benzoquinone (I) [583-63-1] and 4-methyl-1,2-benzoquinone (II) [3131-54-2] had high apparent activation energies of 18 and 23 kcal/mol, resp., whereas tetrachloro-o-quinone (III) [2435-53-2], tetrabromo-o-quinone (IV) [2435-54-3], caffeic acid quinone (V) [15416-77-0] and chlorogenic acid quinone (VI), 3-hydroxy-1,2-benzoquinone [15258-70-5], 3-hydroxy-5-carboxy-1,2-benzoquinone [65271-60-5], 4-hydroxy-1,2-benzoquinone [65271-61-6], Me caffeate quinone [1782-53-2] and 1,2-naphthoquinone [524-42-5] had apparent activation energies in the 2-10 kcal/mol range. Both I and its derivs. were unstable in aq. solns., the rate of their hydration and redn. increased with their increasing concn. and with pH increasing to 11. The decompn. was catalyzed by the corrsponding phenols. At the initial concn. below 5 ′ 10-4M the reaction was very slow. In most cases the reaction was of the 2nd order; but in case of II, III, and IV the order changed from the 1st to 2nd; and for I, V, and VI the reaction was of 1st order, esp. at the start of the expts.