KINETIC AND THERMODYNAMIC ASPECTS OF METALLO - N-ALKYLPORPHYRINS.
Item
-
Title
-
KINETIC AND THERMODYNAMIC ASPECTS OF METALLO - N-ALKYLPORPHYRINS.
-
Identifier
-
AAI8409405
-
identifier
-
8409405
-
Creator
-
KUILA, DEBASISH.
-
Contributor
-
David K. Lavallee
-
Date
-
1984
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Chemistry, Inorganic
-
Abstract
-
The occurrence of N-substituted porphyrins in animals and the possibility of using these compounds for therapy have stimulated an interest in their kinetic and thermodynamic properties. In the kinetic section of the dissertation, the dealkylation reactions which produce non-N-substituted metalloporphyrins are discussed. A variety of thermodynamic properties are presented in the subsequent chapters.;The nature of the solvent medium and nucleophile cause a pronounced effect on the dealkylation reactions of Cu(II) complexes of N-substituted porphyrins. The reactions are much slower in water than in acetonitrile(by about 100-fold) and dichloromethane(by about 10-fold). Amines are much better nucleophiles than pyridine or chloride ions. Porphyrin ring substituents have no mazor effect on the dealkylation reaction. However, the N-substituent has a profound effect. For example, under the similar conditions, the p-nitrobenzyl moiety is cleaved about 100 times faster than the methyl group and 1000 times faster than the ethyl group. Such carbocation-stabilizing substituents, therefore, should be useful in the rapid synthesis of radiolabelled metallonon-N-alkylporphyrins.;Thermodynamic features of N-substituted porphyrin complexes which have been investigated include structural, electrochemical, epr and XPS properties. Comparisons of N-aryl(i.e. N-phenyl) and N-alkyl complexes show that the geometries in the solid state, electrochemical properties and spectroscopic properties are generally very similar. Large differences are evident, however, when N-substituted and non-N-substituted complexes are compared. For example, redox potentials greatly favor the reduced form of metallo-N-alkylporphyrins (Fe(II) and Mn(II)) and the cyclic voltammograms are highly reversible or quasi-reversible for non-N-substituted species. The reduction of Cu(II) to CU(I) is evident in the voltammogram and is strongly affected by axial ligations.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
-
Program
-
Chemistry
