Acidity constant pJCa value

This equilibrium may be treated thermodynamically and the equilibrium constant may be estimated from the Forster Cycle, as shown in Figure 2.17. This cycle illustrates the enthalpy differences between the acid and base forms of the ground-and excited-state species. According to such a scheme, the difference between the ground- and excited-state pJCa values may be estimated from the ground-state... 

The acid constants were determined from the pJCa values obtained from 0.05N NaOH electrometric titration curves (hydrogen electrode). Experimentally it was impossible to measure all the compounds by this method, since some were extremely insoluble (sic) in water, and because of their high molecular wei ts, the pJC values were not significant. For the very insoluble (sic)... 

Willi AV 5. Die Aciditatskonstanten von Benzolsulfonamiden und ihre Beeinflussbarkeit durch Substitution (Effect of substitution on the acidity constants for benzenesulfonamides), Helv. Chim. Acta, 39, 46-53 (1956). NB This paper reported pJCa values for the following substituted benzenesulfonamides. The pJC values were treated according to the Hammett equation ... 

Neudert W and Ropke H, The physico-chemical properties of the disodium salt of adipic acid bis(2,4,6-triiodo-3-carboxyanilide) and other triiodobenzene derivatives, Chem. Ber., 87, 659-667 (1954). Cited in Lemer HH, lodipamide, APDS, 3,333-363 (1974). NB This pJCa value may be a statistically modified composite of and pKs2, since boBi dissociation constants can be expected to be very similar in value. 

Schill G and Gustavii K, Acid dissociation constants of morphine, Acta Pharm. Suec., 1, 24-35 (1964). Cited in Perrin Bases Suppl no. 7484. NB Glass electrode was only calibrated at pH = 9.20 at 20 ° C. The values were validated by comparisons with pJCa values for monofunctional morphine derivatives and checked by potentiometric and partitioning (against dichloromethane) experiments. Reported also codeine (8.26) ethylmorphine (8.33) morphine N-methyl bromide (8.83). 

Wiseman EH, Chang Y-H and Lombardino JG, Piroxicam, a novel anti-inflammatory agent, Arzneim.-Forsch., 26,1300-1303 (1976). NB "An acidity constant (piCJ was determined by potentiometric titration of piroxicam in 2 1 dioxane-water. .. at 25 °C. The apparent pJCa value was estimated from die half-neutralization point... 

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