Document Type

Thesis - University Access Only

Award Date

1997

Degree Name

Master of Science (MS)

Department / School

Chemistry and Biochemistry

Abstract

Stable complexes are an excellent tool for luminescent labels because of the minimized loss of label to the solvent and the reduction of metal scrambling during multilabel experiments. Complexes of lanthanide (III) ions of Tb, Eu, Sm, and Dy with 1,4,7,10-tetraazacyclododecane tetraacetic acid (DOTA) show complexation coefficients of up to 1027, exhibiting the desired high stability. Applications of the lanthanide complexes are becoming increasingly useful in a variety of ways, including: wildlife tracking, DNA sequencing, trace metal analysis, fluoroimunoassays, magnetic resonance imaging shift reagents, and optical imaging of tissues. The monitoring of the above applications is accomplished by taking advantage of the narrow luminescence lines exhibited by the lanthanide (Ln(III)) metals. Low absorption and long lived emissive excited states are the result of the f-f transitions being formally forbidden. Through the use of photon counting and gated boxcar averaging, the long life of the luminescent excited state is used to increase the sensitivity of detection. However, the low absorption of light is a hindrance. The antenna effect is used to overcome this problem. The antenna group absorbs the excitation energy and transfers this energy to the metal centers. Lanthanide complexes with DOTA have not been well studied. The energy transfer from organic triplet sensitizers to the Ln(III) ions complexed with DOTA is the focus of this research. Work described in this paper includes an overall scale up of the cyclen synthesis. The energy transfer from several triplet sensitizers to Eu-DOTA complexes were studied in aqueous and organic solvents. The emission lifetimes of EuDOTA and TbD03A-pmap were also studied.

Library of Congress Subject Headings

Luminescence

Rare earth metals

Photochemistry

Format

application/pdf

Number of Pages

62

Publisher

South Dakota State University

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