Heteroaromatic compounds, covalent hydration

Hammett equation, applied to azines, 217 Hetarynes, 121-143 contrasted with arynes, 125 Heteroaromatic compounds, covalent hydration of, 1-41 "pKa generalizations for, 48-61 Heterocyclic acids, pH-rate profile for, 67 Heterocyclic diazonium compounds, 241 Heptaazanaphthalenes, 393 Hexaazanaphthalenes, 393 Hippuroflavin, 80 Hydrated salts, isolation of, 16 Hydrates, alcoholates from, 16 isolation of, 16... 

Of all the heteroaromatic compounds that have been examined qualitatively and quantitatively for covalent hydration, the pteridines constitute the largest series. Most of the quantitative relationships which were used in earlier discussions were first derived for the hydroxypteridines. Also most of the known examples of hydration in anions were found in this series. 

An understanding of covalent hydration is essential for all who work with heteroaromatic compounds containing doubly bonded nitrogen atoms. As chemists become more aware of the circumstances in which hydration occurs, and the means for detecting it, many new examples will probably be discovered and many puzzling discrepancies solved. Many of the values for ionization constants and ultraviolet spectra which are in the literature refer to partly hydrated equilibrium mixtures and should be replaced by values for the pure substances. 

Covalent Hydration in Nitrogen Heteroaromatic Compounds II. Quantitative Aspects... 

Covalent Hydration in Nitrogen-Containing Heteroaromatic Compounds I, Qualitative Aspects A. Albert and W. L. F. Armarego, Adv. Heterocycl. Chem., 1964, 4, 1-42. Covalent Hydration in Nitrogen Heteroaromatic Compounds II, Quantitative Aspects D. D. Perrin, Adv. Heterocycl. Chem., 1964, 4, 43-73. 

Albert, A., Armarego, W. L. F., Covalent Hydration in Nitrogen-Containing Heteroaromatic Compounds. I. Qualitative Aspects, 4, 1. 

Coordinated ligands, reactions of, 58, 123 Covalent hydration in heteroaromatic compounds, 4, 1, 43 in nitrogen heterocycles, 20, 117 Current views on some physicochemical aspects of purines, 24, 215 Cyclazines and related N-bridged annulenes, 22, 321... 

Covalent Hydration in Nitrogen-Containing Heteroaromatic Compounds I. Qualitative Aspects... 

Heteroaromatic compounds free-radical substitutions of, 2, 131 homolytic substitution of, 16, 123 nitrogen, covalent hydration in, 4, 1, 43 prototropic tautomerism of. 1, 311,339 2, I, 27 SI... 

---