Acid-base and coordination properties of Meso-substituted porphyrins in nonaqueous solutions

作者：Pukhovskaya S G^*; Dao Tkhe Nam; Fien Chan Ding; Domanina E N; Ivanova Yu B; Semeikin A S

来源：Russian Journal of Physical Chemistry, 2017, 91(9): 1692-1702.

DOI：10.1134/S0036024417090242

• porphyrins
• acid-base properties
• electronic effects of substituents
• structure
• kinetics
• coordination properties

Acid-base and coordination properties of alkyl and aryl meso-substituted porphyrins are studied spectrophotometrically in nonaqueous solutions. It is found that the nature of the substituent greatly affects the basicity of ligands for porphyrins characterized by a flat structure of macrocycle. The electronic effects of substituents have a much weaker influence on the kinetics of complexing. These effects could be due to the opposite orientation of some factors: an increase in the basicity and stability of the N-H bonds of porphyrin reaction centers. Dissociation constants pK (b) of the cationic forms of meso-substituted derivatives of porphyrin are measured. The values of pK (b) are in good agreement with classic concepts of the nature of substituents, particularly those indirectly included in the macrocycle through phenyl buffer rings.

• 出版日期2017-9
• 单位北京化工大学