THE EMISSION OF PYRIDINE AND POLYPYRIDINECHROMIUM(III) COMPLEXES IN RIGID AND FLUID MEDIA.

Persistent Link:
http://hdl.handle.net/10150/184143
Title:
THE EMISSION OF PYRIDINE AND POLYPYRIDINECHROMIUM(III) COMPLEXES IN RIGID AND FLUID MEDIA.
Author:
GHAITH, ABDULATIF MOHAMMAD.
Issue Date:
1987
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The excited state emissions and lifetimes of [Cr(bipy)₃]³⁺, cis – [Cr(bipy)₂Cl₂]⁺, trans – [Cr(py)₄FBr]⁺, cis – [Cr(phen)₂F₂]⁺, and trans – [Cr(py)₄F₂]⁺ were studied in hydroxylic and nonhydroxylic solvents at 77 K and as a function of temperature. The emission characteristics are determined by the relative disposition of ²E and one component of ²T₁. The energy of these two levels is influenced by intramolecular and environmental factors, and solvent-induced level inversion occurs in cis – [Cr(phen)₂F₂]⁺. The influence of temperature and solvent viscosity were studied in several glasses with variable melting ranges. The emission of all of the complexes, except [Cr(bipy)₃]³₊, were found to be influenced by solvent viscosity. This influence is large when ²E and the component of ²T₁ are close in energy, and level inversion upon melting of the solvent occurs in cis –[Cr(phen)₂F₂]⁺. The decay of the emission of Cr(III) complexes normally shows small temperature dependence at lower temperatures and large temperature dependence at higher temperatures. The threshold for the appearance of strong temperature dependence depends on intramolecular and environmental factors. The decays of all the complexes except [Cr(bipy)₃]³⁺ show strong discontinuities in the rigid-fluid transition regions of the solvent glasses which are accompanied by risetimes in the decay profiles when the emission intensity is monitored at long wavelengths. This is attributed to solvent relaxation during the excited state lifetime.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Organochromium compounds -- Decay.; Chemiluminescence.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Rund, John V.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTHE EMISSION OF PYRIDINE AND POLYPYRIDINECHROMIUM(III) COMPLEXES IN RIGID AND FLUID MEDIA.en_US
dc.creatorGHAITH, ABDULATIF MOHAMMAD.en_US
dc.contributor.authorGHAITH, ABDULATIF MOHAMMAD.en_US
dc.date.issued1987en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe excited state emissions and lifetimes of [Cr(bipy)₃]³⁺, cis – [Cr(bipy)₂Cl₂]⁺, trans – [Cr(py)₄FBr]⁺, cis – [Cr(phen)₂F₂]⁺, and trans – [Cr(py)₄F₂]⁺ were studied in hydroxylic and nonhydroxylic solvents at 77 K and as a function of temperature. The emission characteristics are determined by the relative disposition of ²E and one component of ²T₁. The energy of these two levels is influenced by intramolecular and environmental factors, and solvent-induced level inversion occurs in cis – [Cr(phen)₂F₂]⁺. The influence of temperature and solvent viscosity were studied in several glasses with variable melting ranges. The emission of all of the complexes, except [Cr(bipy)₃]³₊, were found to be influenced by solvent viscosity. This influence is large when ²E and the component of ²T₁ are close in energy, and level inversion upon melting of the solvent occurs in cis –[Cr(phen)₂F₂]⁺. The decay of the emission of Cr(III) complexes normally shows small temperature dependence at lower temperatures and large temperature dependence at higher temperatures. The threshold for the appearance of strong temperature dependence depends on intramolecular and environmental factors. The decays of all the complexes except [Cr(bipy)₃]³⁺ show strong discontinuities in the rigid-fluid transition regions of the solvent glasses which are accompanied by risetimes in the decay profiles when the emission intensity is monitored at long wavelengths. This is attributed to solvent relaxation during the excited state lifetime.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectOrganochromium compounds -- Decay.en_US
dc.subjectChemiluminescence.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorRund, John V.en_US
dc.identifier.proquest8726804en_US
dc.identifier.oclc698765413en_US
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