Identifier

etd-07102009-101519

Degree

Master of Science (MS)

Department

Chemistry

Document Type

Thesis

Abstract

In nature, self-assembly processes of biologically active organic molecules often occur, resulting in formation of dimers and higher oligomers of various and sometimes complex structures. This natural occurrence of self-organization has been the subject of research, with the aim of understanding and possibly modulating the aggregation behavior of biological molecules. The meso-tetrakis(4-phosphonatophenyl) porphyrin, H2TPPP was synthesized, purified, and characterized. Its self-assembly was studied in aqueous solutions as a function of pH and time. The variations on the λmax and shape of the Soret band of this porphyrin in the absorption spectra when altering the pH indicated the pH dependency in the hierarchical self-assembly of H2TPPP in aqueous solution. The aggregation as a function of time was monitored via fluorescence spectroscopy, where the emission intensity decrease suggests self-quenching and aggregation. Small angle x-ray scattering experiments were conducted in an attempt to obtain structural information for the self-organized porphyrin complexes. Analytical ultracentrifugation techniques confirmed reported SAXS results and also revealed the self-associative behavior of the aggregates.

Date

2009

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Graca H. Vicente

Included in

Chemistry Commons

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