I. A CARBON-13 NMR STUDY OF METAL ION POLARIZABILITY. II. PALLADIUM PORPHYRINS: PHARMACEUTICAL USE AND REACTION KINETICS.
Item
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Title
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I. A CARBON-13 NMR STUDY OF METAL ION POLARIZABILITY. II. PALLADIUM PORPHYRINS: PHARMACEUTICAL USE AND REACTION KINETICS.
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Identifier
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AAI8222941
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identifier
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8222941
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Creator
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DOI, JON DAVID.
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Contributor
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Dr. David K. Lavallee
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Date
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1982
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Inorganic
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Abstract
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Part I. Although several methods to determine the effective electron density or polarizing ability of a metal ion are presently available, these techniques have limited applicability. The purpose of this project is to investigate whether ('13)C NMR chemical shifts at the para position of the bound ligand, pyridine, correlate well with the effective electron density of the metal center.;The ('13)C NMR chemical shifts for the para carbon atom of pyridine bound to these diamagnetic metal ions Zn(II), Cd(II), Ag(I), Co(III) and Rh(III) show an excellent correlation with pKa values calculated from optical basicity data but show a much poorer correlation with experimental pK(,a) values. The strong correlation with electrostatic force considerations is consistent with the use of ('13)C chemical shifts as an empirical measure of the polarizing power of metal ions. From the magnitude of chemical shift values, large changes in polarizability are readily observable but small shift changes, such as those caused by ligand substitution on a particular metal ion, are not likely to be seen.;Part II. Chapter I. Selective lymphatic ablation on rats by use of ('109)Pd-hematoporphyrin has been reported. The literature preparation of this complex results in too large a loss in activity for experiments with large animals and human subjects. The palladium complex can be rapidly and quantitatively prepared using N-methylhematoporphyrin in dimethylsulfoxide. Distribution, toxicity and transplantation studies on dogs give promising results but additional experiments need to be run. Chapter 2. The mechanism of metalloporphyrin formation involving a metal salt and a N-methylporphyrin follows a two-step pathway: complexation, to form the metalated N-methylporphyrin intermediate and demethylation of the intermediate to form the planar metalloporphyrin. The rates for the reactions involving Pd(NO(,3))(,2)(.)xH(,2)O and N-methyltetraphenylporphyrin in acetonitrile, N,N-dimethylformamide and dimethylsulfoxide were determined.;The results in acetonitrile show that the demethylation reaction is rate determining. When combined with results previously reported, the reactivity order: Pd(II) > Cu(II) Ni(II) > Zn(II) > Mn(II) closely follows the stability of the planar porphyrin products. The results in N,N-dimethylformamide and dimethylsulfoxide are less clear. However, it is apparent that the rate determining step in these solvents is the complexation reaction.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Chemistry
