Chemistry and Biochemistry
Bayer School of Natural and Environmental Sciences
ATRA, ATRP, Polymers, Mass Spectrometry, GPC, NMR
This work is focused on the synthesis, characterization, and application of functionalized materials prepared from atom transfer radical processes. Atom transfer radical processes encompass both atom transfer radical addition (ATRA) and polymerization (ATRP) reactions, both of which are catalyzed by ppm amounts of copper complexes. The synthetic efforts of ATRA include increasing adduct selectivity through optimization of reaction conditions to generate small molecules in high to moderate yields. ATRA provides retention of the halogen moiety, which is an attractive functional group that can be further modified with other transformations. Specifically, the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) allows for the realization of various applications due to the robust nature and host of “click-able” targets. This, in conjunction with the stout nature of ATRA, enables these materials to have use in all aspects of biomedical applications.
ATRP reactions were primarily utilized to prepare homo- and block copolymers using a photoinduced methodology. The photoATRP reaction enables polymerization of various acrylate-based monomers in a one-pot, multi-step fashion, generating block copolymers without the need for polymer isolation prior to additional block additions. Specifically, the photoATRP reaction was utilized to generate amphiphilic block copolymers containing a hydrophilic/hydrophobic section. When subjected to specific environments (solvent/temp/concentration/etc.), these amphiphiles have the ability to form micelles, of which can be utilized for small molecule encapsulation. These polymers would find use in all areas of biomedicine, such as bioimaging or drug delivery. It was envisioned that the polymerization could be employed to a host of multifunctional/star-shaped initiators, which may enable the formation of unimolecular micelles, a characteristic which is highly sought over.
Additionally, ATRP was utilized to prepare polymeric materials to characterize by means of MS/MS. Very similar to proteomics, subjecting these polymeric materials to collisional induced dissociation (CID) experiments enables proficient end-group and block identification based on measured fragments.
This work provides significant contributions to several fields: small molecule synthesis using ATRA in conjunction with CuAAC, block copolymer formation via ATRP, as well as the application of functionalized materials from the aforementioned methods. Moreover, these materials acted as an excellent scaffold to conduct MS/MS experiments to contribute to the growing field commonly referred to as “polymeromics.”
Fischer, S. (2020). Functionalized Materials from Atom Transfer Radical Processes (Doctoral dissertation, Duquesne University). Retrieved from https://dsc.duq.edu/etd/1931