SYNTHESIS OF 2,2'-BIPYRIDINE-LIKE BRIDGING LIGANDS AND ABSORPTION, LUMINESCENCE AND ELECTROCHEMICAL STUDIES OF THEIR MONONUCLEAR AND BINUCLEAR RUTHENIUM (II) COMPLEXES.
Item
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Title
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SYNTHESIS OF 2,2'-BIPYRIDINE-LIKE BRIDGING LIGANDS AND ABSORPTION, LUMINESCENCE AND ELECTROCHEMICAL STUDIES OF THEIR MONONUCLEAR AND BINUCLEAR RUTHENIUM (II) COMPLEXES.
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Identifier
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AAI8401921
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identifier
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8401921
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Creator
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BRAUNSTEIN, CARLOS HUGO.
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Contributor
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Prof. Arthur D. Baker
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Date
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1983
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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, Organic
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Abstract
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The ligands ethyl 2-(2'pyridyl)cinchonate, , 2,3-(2'-pyridyl)pyrazine, , 4,5-diazafluoren-9-one azine, , and 2,2'-dipyridyl glyoxime, , have been used to prepare the complexes (bpy)(,2)RuL('2+) and (bpy)(,2)RuLRu(bpy)(,2)('4+). In contrast to previously synthesized mono-and bimetallic Ru(II) complexes, (bpy)(,2)RuL('2+) and (bpy)(,2)RuLRu(bpy)(,2)('4+) (L = ) are luminescent in room temperature fluid solution. The resonance Raman spectra of the mono- and bimetallic complexes of compound exhibit a pronounced dependence on excitation wavelength which indicates that the visible MLCT transitions terminate in different ligands. Luminescence is assigned to a ligand (pi)*-Ru(II) t(,2) transition and measurements of the relative quantum yields of emission indicate that the emissive state is populated with equal efficiency in both complexes. Analysis of the electrochemical and spectral properties of the complexes indicates that the perturbation induced by the second Ru(bpy)(,2)('2+) moiety in (bpy)(,2)RuLRu(bpy)(,2)('4+) (L= ) is relatively small and similar to that introduced by substituting a weak electron withdrawing substituent onto the ligand periphery. This relatively weak interaction, which is thought to be the reason why both mono- and bimetallic complexes emit, is attributed to steric constraints imposed by ligand . The spectroscopic properties of (bpy)(,2)Ru('2+) (L = ) and (bpy)(,2)RuLRu(bpy)(,2)('4+) (L = ) are also discussed.
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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
