Jamison & Johnson Collaborative Paper Highlighted in C&E News

Danielle Randall
August 20, 2015

Scalable Synthesis of Sequence-Defined, Unimolecular Macromolecules by Flow-IEG, a collaborative paper by Assistant Professor Jeremiah A. Johnson and Department Head/Professor Timothy F. Jamison, was published in Proceedings of the National Academy of Sciences of the United States of America and highlighted with an article in Chemical & Engineering News.  The research, which features the development of Flow-IEG," a semi-automated coupling and modification technique that makes it possible to easily synthesize sequence- and length-defined linear and branched non-biological polymers", was presented at the national meeting of the American Chemical Society in Boston this past week.

Frank A. Leibfarth, Jeremiah A. Johnson, and Timothy F. Jamison

Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139

We report a semiautomated synthesis of sequence and architecturally defined, unimolecular macromolecules through a marriage of multistep flow synthesis and iterative exponential growth (Flow-IEG). The Flow-IEG system performs three reactions and an in-line purification in a total residence time of under 10 min, effectively doubling the molecular weight of an oligomeric species in an uninterrupted reaction sequence. Further iterations using the Flow-IEG system enable an exponential increase in molecular weight. Incorporating a variety of monomer structures and branching units provides control over polymer sequence and architecture. The synthesis of a uniform macromolecule with a molecular weight of 4,023 g/mol is demonstrated. The user-friendly nature, scalability, and modularity of Flow-IEG provide a general strategy for the automated synthesis of sequence-defined, unimolecular macromolecules. Flow-IEG is thus an enabling tool for theory validation, structure–property studies, and advanced applications in biotechnology and materials science.