Boyd, Mary K. published the artcileWater quenching behavior of excited 9-xanthylium cations in aqueous sulfuric acid solutions, SDS of cas: 596-38-3, the publication is Journal of the American Chemical Society (1991), 113(19), 7294-300, database is CAplus.
A series of 9-alkyl- and 9-aryl-substituted xanthylium cations (I; R = H, Me, Me2CHr, cyclo-Pr, tert-Bu; II; R1 = H, p-CF3, p– and m-Me, p– and m-OMe) were generated from the corresponding 9-xanthenols in strongly acidic aqueous MeCH (2:1) solutions (39-78% H2SO4). Steady-state irradiation at 370 nm produced the excited cations, all of which were fluorescent in the 520-nm region. Fluorescence lifetimes varied considerably with acid concentration, from subnanosecond values at low acidity to 20-35 ns at high acidity. Stern-Volmer plots of ΦF°/ΦF vs. the free water concentration in these acid solutions gave linear plots in all cases, yielding kq values in the 106-109 M-1 s-1 range, depending on substituents. For the 9-aryl systems, a plot of log kq vs. a recently determined σhν scale was reasonably linear (r = 0.974) with a ρ value of -1.5, which is opposite in sign to that recently determined for H2O quenching of the same cations in their ground states. Possible explanations for this surprising result are considered.
Journal of the American Chemical Society published new progress about 596-38-3. 596-38-3 belongs to alcohols-buliding-blocks, auxiliary class Other Aromatic Heterocyclic,Benzene,Alcohol, name is 9-Phenyl-9H-xanthen-9-ol, and the molecular formula is C19H14O2, SDS of cas: 596-38-3.
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