Redox reagents based on 2,2',4,4'',4',4'''-quaterpyridyl and 4,7'-phenanthrolino-5',6':5,6 -pyrazine.
Item
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Title
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Redox reagents based on 2,2',4,4'',4',4'''-quaterpyridyl and 4,7'-phenanthrolino-5',6':5,6 -pyrazine.
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Identifier
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AAI9218250
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identifier
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9218250
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Creator
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Morgan, Robert John.
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Contributor
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Adviser: A. D. Baker
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Date
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1992
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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 | Chemistry, Organic
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Abstract
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The title ligands, and a series of Ru(II) polypyridine complexes containing the title ligands, have been prepared and characterized. The ground and excited state redox and acid-base properties of the quaterpyridyl complexes (Ru(bpy){dollar}\sb2{dollar}qpy) {dollar}\sp{lcub}2+{rcub}{dollar} (bpy = 2,2{dollar}\sp\prime{dollar}-bipyridine), and its N-methylated derivatives ( (qpyme) {dollar}\sp{lcub}+{rcub}{dollar} and (qpyme{dollar}\sb2\rbrack\sp{lcub}2+{rcub}),{dollar} have been measured. (Ru(bpy){dollar}\sb2{dollar}qpy) {dollar}\sp{lcub}2+{rcub}{dollar} is highly luminescent (660 nm) and has a large quantum yield (0.053 in water), a long excited state lifetime (569 ns in water), and a first pK{dollar}\sb{lcub}\rm a{rcub}{dollar} of 4.2. Quaternization of the remote pyridine rings of the quaterpyridyl generally decreases the quantum yield, and red shifts the emission and absorption maxima. (Ru(qpy){dollar}\sb3\rbrack\sp{lcub}2+{rcub}{dollar} is also a powerful emitter, with a quantum yield of emission of 0.14 in methanol, and an excited state lifetime of 991 ns in water.;The photoredox properties of monomeric, dimeric, and Pt(II) heterobinuclear Ru(II) complexes containing the bis-bidentate bridging ligand ppz reveal that the metal centers of luminescent, homobinuclear ((bpy){dollar}\sb2{dollar}RuppzRu(bpy){dollar}\sb2\rbrack\sp{lcub}4+{rcub}{dollar} are not coupled. ((bpy){dollar}\sb2{dollar}RuppzPtCl{dollar}\sb2\rbrack\sp{lcub}2+{rcub},{dollar} the first Ru(II)/Pt(II) compound in which the two metal centers share the same {dollar}\pi{dollar}- system, is non-luminescent and its metal centers are strongly coupled.;The interaction of mixed ligand complexes of the type (Ru(bpy){dollar}\sb2{dollar}L) {dollar}\sp{lcub}2+{rcub}{dollar} L = ppz, ppzPtCl{dollar}\sb2,{dollar} qpy, (qpyme) {dollar}\sp{lcub}+{rcub}{dollar} or (qpyme{dollar}\sb2\rbrack\sp{lcub}2+{rcub}{dollar} with calf thymus DNA has been investigated by absorption, emission and circular dichroism (CD) spectroscopy, and equilibrium dialysis binding studies. Resolved spectral features of the ligand L simplify interpretation of the spectra regarding intercalation.;A novel method for the enantiomeric resolution of certain tris-chelates of ruthenium(II) has been developed. Passing an aqueous solution of (Ru(phen)) {dollar}\sb3\sp{lcub}2+{rcub}{dollar} or Ru(bpy){dollar}\sb2{dollar}ppz{dollar}\sp{lcub}2+{rcub}{dollar} through a column containing DNA adsorbed onto hydroxylapatite, gives fractions which are {dollar}>{dollar}95% enantiomerically pure, and an additional pass results in pure isomers. We report the {dollar}\Delta\varepsilon{dollar} values for the {dollar}\Delta{dollar} and {dollar}\Lambda{dollar} isomers of the ppz complex. Qualitative results for the complex (Ru(bpy){dollar}\sb2{dollar}phen) {dollar}\sp{lcub}2+{rcub}{dollar} indicate that a minimal complement of ligands, in which only one is competent to intercalate within the major groove of B-form DNA can form the basis for highly enantioselective interaction.
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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.
