Enzyme-like catalysis by single chain nanoparticles that use transition metal cofactors

Xiong, Thao Mee

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https://hdl.handle.net/2142/114057 Copy

Description

Title

Enzyme-like catalysis by single chain nanoparticles that use transition metal cofactors

Author(s)

Xiong, Thao Mee

Issue Date

2021-11-11

Director of Research (if dissertation) or Advisor (if thesis)

Zimmerman, Steven C

Doctoral Committee Chair(s)

Zimmerman, Steven C

Committee Member(s)

• Chan, Jefferson
• Fout, Alison R
• Moore, Jeffrey S

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• single chain nanoparticle
• artificial metalloenzyme

Abstract

A strategy to improve the catalytic activity of transitional metal-based catalysis in the complex biological environment mimics metalloenzymes by folding a polymer chain around a metal center to form single chain nanoparticles (SCNPs). Herein I report two strategies for the preparation of transition metal-SCNPs. First, we developed a noncovalently cross-linked amphiphilic polymer with covalently attached catalyst that allows substrate binding for higher catalytic activity. Next, I developed a modular approach in which a noncovalently cross-linked SCNP formed from the folding of an amphiphilic polymer selectively binds catalyst “cofactors” and substrates to increase their proximity and resultant catalytic activity. The polymers were synthesized by free radical polymerization and post-polymerization functionalization with amines and characterized by NMR, GPC, and DLS. Fluorescence studies demonstrated the SCNP’s ability to increase the catalytic activity of a Cu-catalyzed alkyne-azide cycloaddition reaction and the Ru-catalyzed cleavage of allylcarbamate groups compared to the free catalysts. A small library of Cu and Ru catalysts with different alkyl chain lengths, functional groups, and charges was used to develop a structure-activity relationship. Ligand binding to the SCNP was identified and characterized by NOESY and STD NMR experiments. These results demonstrate the potential of this plug-and-play strategy for obtaining functional transition metal-SCNPs. We also utilized polymers for ketal-based cross-linked polyamide microcapsules. Under acidic conditions, the microcapsules degrade and release anticorrosion active agents. They were embedded in commercially available coatings to obtain self-protecting coatings.

Graduation Semester

2021-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/114057

Copyright and License Information

Copyright 2021 Thao Mee Xiong

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