Acid−Base Equilibrium Constants for Glycine in NaClO4, KCl, and KBr at 298 K. Dependence on Ionic Strength

1998 ◽  
Vol 43 (5) ◽  
pp. 876-879 ◽  
Author(s):  
P. Alonso ◽  
J. L. Barriada ◽  
P. Rodríguez ◽  
I. Brandariz ◽  
M. E. Sastre de Vicente
Keyword(s):  
Ionic Strength ◽  
Equilibrium Constants ◽  
Acid Base ◽  
Base Equilibrium ◽  
Acid Base Equilibrium ◽  
Dependence On Ionic Strength

Synthesis, Acid-Base Properties, Kinetics and Mechanism of Cu2+ Incorporation into Water-Soluble Highly Substituted Porphyrins

2017 ◽  
Vol 21 (09) ◽  
pp. 611-621
Author(s):  
Hirofumi Konno ◽  
Jun Takeda
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Kinetics And Mechanism ◽  
Water Soluble ◽  
Acid Base ◽  
Base Equilibrium ◽  
Absorbance Change ◽  
Acid Base Equilibrium ◽  
Kinetics Of ◽  
Base Properties

The synthesis, acid-base properties, and kinetics of Cu[Formula: see text] incorporation into water-soluble highly substituted porphyrins were studied. The basicity increased and the stepwise acid-base equilibrium was clarified by increasing the number of phenyl groups at the [Formula: see text] position, and the basicity of a dodeca-substituted porphyrin increased with the ionic strength. The metalation reaction of the dodeca-substituted porphyrin with Cu[Formula: see text] in aqueous solution revealed a biphasic absorbance change at 453 nm. Plots of [Formula: see text] or[Formula: see text] vs. the Cu[Formula: see text] concentration and of log ([Formula: see text] or[Formula: see text]/[Formula: see text] 0) vs. the ionic strength show that [Formula: see text] is dependent on the Cu[Formula: see text] concentration and ionic strength, while [Formula: see text] is independent of these parameters. These results confirm the stepwise metalation mechanism and the existence of an intermediate in aqueous solution, which is indicated by the biphasic absorbance change at 453 nm.

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