Date of Award

6-1996

Document Type

Open Access

Degree Name

Bachelor of Science

Department

Chemistry

Language

English

Abstract

Cyclodextrin polymers (CDPs) are water Joluble polymers composed of either a, fl, or y cyclodextrin (CDl monomers. TI,ese commercially available polymers are synthesized ming epichlorohydrin and consist of CD monomers joined by repeating glycer;l linkers (-(CH2-CHOH-CH2-ln) with an average n value of 12-15. GPC analysis of these polymers indicate two major component peaks that have molecular weights (MW) of 2,000 (one CD/ polymer chain) and 9-10,000 (4-5 CDs/polymer chain). These polymers have been used to study the binding interactions of various fluorescence probes. It has been shown that the pyrene fluorescence lifetime increases and its emission I/III ratio decreases in the hydrophobic CD c.avity. In addition, it has been reported that pyrene exists in a more open, hydrophilic environment when bound to the CDPs than that observed with the CDs. We have used these fluorescence properties to study the binding of pyrene to our synthesized fl-CDPs with shorter linker units. We have shown that as the MW of the synthesized fl-CDPs increases (increase in length of linker units), the pyrene I/III increases and the fluorescence lifetime decreases, indicating a more hydrophilic environment. Competitive experiments involving both fl-CD and commercial fl-CDP indicate that pyrene has a strong affinity for the commercial fl-CDP despite the enhanced hydrophobic environment when complexed with fl-CD. We have calculated a K value for the 1:1 fl-CDP:pyrene complex t<' be 1.9 x 103 using competitive binding experiments.

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