31719-70-7Relevant academic research and scientific papers
Pulse Radiolytic One-electron Oxidation of some Dihydroxy-substituted Anthraquinones
Pal, Haridas,,Palit, Dipak K.,Mukherjee, Tulsi,Mittal, Jai P.
, p. 681 - 688 (1992)
The spectroscopic characteristics and the kinetic parameters associated with the transients formed on one-electron oxidation of quinizarin (1,4-dihydroxy-9,10-anthraquinone), quinizarin 2- and 6-sulfonates, 1,5-dihydroxy-9,10-anthraquinone and 1,8-dihydroxy-9,10-anthraquinone have been studied by pulse radiolysis and kinetic spectrophotometric techniques, using OH., O.-, N3., Br2.- and .CH2CHO as the oxidising radicals.The pKa and the disproportionation equilibria of the semi-oxidised quinones have been studied for the water-soluble sulfonates.In contrast to the complex decay of the semi- oxidised naphthazarin (5,8-dihydroxy-1,4-naphthoquinone), the semi-oxidised anthraquinone derivatives decay by simple second-order kinetics.The pKa values of the latter are also much higher (ca. 8) compared to the former (ca. 4).The differences observed are attributed to the loss in symmetry in the free radical structures of the semi-oxidised anthraquinone derivatives.
