'Sacrificial' supramolecular assembly and pressure-induced polymerization: toward sequence-defined functionalized nanothreads

• Published in: Chemical science (Cambridge) Vol. 11; no. 42; pp. 11419 - 11424
• Main Authors: Gerthoffer, Margaret C, Wu, Sikai, Chen, Bo, Wang, Tao, Huss, Steven, Oburn, Shalisa M, Crespi, Vincent H, Badding, John V, Elacqua, Elizabeth
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 14.11.2020; The Royal Society of Chemistry
• Subjects: Aromatic compounds; Chemistry; Copolymers; Crystal structure; Crystallography; Cycloaddition; Enumeration; Infrared spectroscopy; Mathematical analysis; Optical microscopy; Polarized light; Polymerization; Pressure; Raman spectroscopy; Reaction mechanisms; Spectrum analysis; Substitution reactions; Synchrotrons; Synthesis; X ray photoelectron spectroscopy
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d0sc03904g

Limited supramolecular strategies have been utilized to synthesize sequence-defined polymers, despite the prominence of noncovalent interactions in materials design. Herein, we illustrate the utility of 'sacrificial' aryl-perfluoroaryl supramolecular synthons to synthesize sp 3 -hybridized nanothreads from sp 2 -enriched reactants. Our strategy features A-B reactant pairs in the form of a phenol:pentafluorophenol co-crystal that is preorganized for an electronically-biased and sequence-defined polymerization. The polymerization, initiated at 12 GPa, affords an alternating copolymer featuring exogenous -OH functionalities. The external substitution is confirmed through IR spectroscopy. Importantly, the inclusion of the functional unit provides the first experimental glimpse at reaction mechanism: keto-enol tautomerization that can only occur during cycloaddition is observed through IR spectroscopy. Our approach realizes the first example of a functionalized nanothread and attains sequence definition through sacrificial supramolecular preorganization and presents a further approach for de novo design of complex nanothreads. Supramolecular synthons are exploited to synthesize -OH functionalized sp 3 -rich sequence-defined nanothreads using pressure-induced polymerization of a phenol:pentafluorophenol co-crystal.