作者: JW Bridges , DS Davies , RT Williams
DOI: 10.1042/BJ0980451
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摘要: Abstract 1. The variations with pH (from 36n-sulphuric acid to 10n-sodium hydroxide) of the excitation and fluorescence wavelengths intensity 2-, 3- 4-hydroxypyridine their O- N-methyl derivatives were investigated. 2. 4-Hydroxy- 4-methoxy-pyridine non-fluorescent at all values. 3. cations dipolar ions 3-hydroxypyridine anion fluorescent, but neutral forms not. 4. All 2-hydroxypyridine fluorescent. 5. Pyridoxol, pyridoxal its 5-phosphate, pyridoxamine pyridoxic lactone studied similarly. these compounds, except more fluorescent than 3-hydroxypyridine. 6. most compounds are anions, for pyridoxol, where ion was form. least molecules. appreciably in cases. 7. form examined dianion lactone. 8. 2- 3-methoxypyridine. showed excited-state ionization. excited pKa values determined results discussed reference Weller's (1952) equation relating ground- dissociation constants. 9. ionizations undergone by from data. 10. Stokes shifts various ionic species calculated discussed.