Chemistry and Chemical Biology ETDs

Publication Date

6-1-1962

Abstract

The phenomenon of intramolecular energy transfer was studied using anthranilate, 8-hydroxyquinolate, 2-methyl-8-hydroxyquinolate, and salicylaldehyde rare earth chelates. Line emission characteristic of the rare earth ion was observed whenever the lowest triplet (measured) of the complex was higher in energy than the emitting (resonance) level of the rare earth trivalent ion. The path of energy transfer from the organic portion of the chelate to the rare earth ion was verified as going via the lowest or a nearby triplet state of the complex. Relative quantum yield measurements were made on the anthranilate rare earth series using a photographic method. Gadolinium anthranilate was used as an internal standard with a defined total quantum yield of 1.0. Fluorescence quantum yields varied from 0.04 for ytterbium anthranilate to 0.45 for lutecium and lanthanum anthranilateo. Phosphorescence quantum yields varied from .037 for ytterbium anthranilate to 0.81 for gadolinium anthranilate with an estimated error or 25%. The relative quantum yields or the anthranilates have no simple relationship to the magnetic susceptibilities of the trivalent rare earth ions. Dissociation and decomposition or the rare earth salicylaldehyde chelates were observed. The salicylaldehyde chelatea demonstrate three different types of emission: (i) green phosphorescence (lifetime ~10-3 sec.) attributed to the salicylaldehyde ion, (ii) a yellow phosphorescence with a lifetime of approximately 10-4 seconds in duration attributed to a triplet to ground state transition in a species containing the metal ion, (iii) a relatively long lived (10-1 sec.) afterglow attributed to an electronic transition occurring in either SA, solvated SA or both species. Energy transfer to rare earth ions in salicylaldehyde chelates probably occurs from the excited state measured to be at approximately 17,700 cm-1. This level is thought to be present in one or all three of the opecies M(SA)3, M(SA)2+, M(SA)++.

Language

English

Document Type

Dissertation

Degree Name

Chemistry

Level of Degree

Doctoral

Department Name

Department of Chemistry and Chemical Biology

First Committee Member (Chair)

Glenn Arthur Crosby

Second Committee Member

Guido Herman Daub

Third Committee Member

Milton Kahn

Fourth Committee Member

Jesse LeRoy Riebsomer

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