Synthesis of Crown-Ether Molecular Receptors for Polyoxometalates

Submission Type

Event

Expected Graduation Date

2014

Location

Center for Natural Sciences, Illinois Wesleyan University

Start Date

4-12-2014 2:00 PM

End Date

4-12-2014 3:00 PM

Disciplines

Chemistry

Abstract

Polyoxometalates are a class of polyatomic ions in which several transition metal-oxygen polyhedra are joined together by shared oxygen atoms to form closed, three-dimensional structures. The large diversity in size, charge, composition, and oxidation states of these anions produces a wide range of properties, and even greater range of applications, particularly in catalysis. The recovery and reuse of these anions would be advantageous in many industrial applications such as wood pulp bleaching. Crown ether complexes of alkali metal cations have been reported to interact favorably with polyoxometalates. The goal of this project is to synthesize a crown-ether molecular receptor (Figure 1) that can reversibly interact with different types of polyoxometalates in order to regulate their catalytic activity or recover them from reaction mixtures. After 4'-aminobenzo-15-crown-5 was prepared in four steps using published procedures, two of the 15-crown-5 units were coupled using a difunctional acid chloride. In a final step, the resulting amide-containing receptor will be reduced using lithium aluminum hydride. The chemical properties of the receptor will be investigated.

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Apr 12th, 2:00 PM Apr 12th, 3:00 PM

Synthesis of Crown-Ether Molecular Receptors for Polyoxometalates

Center for Natural Sciences, Illinois Wesleyan University

Polyoxometalates are a class of polyatomic ions in which several transition metal-oxygen polyhedra are joined together by shared oxygen atoms to form closed, three-dimensional structures. The large diversity in size, charge, composition, and oxidation states of these anions produces a wide range of properties, and even greater range of applications, particularly in catalysis. The recovery and reuse of these anions would be advantageous in many industrial applications such as wood pulp bleaching. Crown ether complexes of alkali metal cations have been reported to interact favorably with polyoxometalates. The goal of this project is to synthesize a crown-ether molecular receptor (Figure 1) that can reversibly interact with different types of polyoxometalates in order to regulate their catalytic activity or recover them from reaction mixtures. After 4'-aminobenzo-15-crown-5 was prepared in four steps using published procedures, two of the 15-crown-5 units were coupled using a difunctional acid chloride. In a final step, the resulting amide-containing receptor will be reduced using lithium aluminum hydride. The chemical properties of the receptor will be investigated.