Title

Synthesis and Study of the Recognition Properties of Non-chiral and Chiral Porphyrin-Calixarene Hybrid Hosts

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

Summer 2017

Abstract

Supramolecular chemistry is a multi-disciplinary field and is described as "Chemistry beyond the molecule". Host-Guest binding and molecular recognition are important concepts in supramolecular chemistry. Chiral recognition is an emerging area of research in the field of molecular recognition. This thesis has a dual focus. The first goal was to synthesize and study alkyl-substituted porphyrins, where an alkyl group is positioned within the binding pocket of porphyrin hosts to attempt to hinder the internal co-ordination of oxygen of urea to Zn metal. If the steric interaction of the alkyl groups inhibited urea oxygen-zinc internal coordination, we expected to observe an effect on binding constants to guest and possibly on the stereoselectivity observed in guest binding. The second goal was to synthesize and study both achiral and chiral porphyrin-calixarene hybrids. The hydrophobic cavity of calixarenes offers another binding point for guest binding in addition to porphyrin binding sites, thus increasing the interaction of guest with host. It was anticipated that the additional binding pocket provided by the calixarene may lead to enhancements in guest binding strength, or guest binding stereoselectivity in the case of chiral recognition studies, or it may lead to the ability to bind guests of different structure/functionality than is typically able to coordinate to porphyrins studied by the Starnes’ group. In both cases, porphyrin isocyanate was reacted with amines to synthesize the hosts. Chiral recognition studies were performed by titrating host solutions with guest solutions and following the titrations using UV/VIS spectroscopy. From the UV/Vis titration studies, it was observed that Calixarene and porphyrin together exhibited co-operative binding of host and guest.

Advisor

Stephen D Starnes

Subject Categories

Chemistry | Physical Sciences and Mathematics

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