Single-Crystal Polycationic Polymers Obtained by Single-Crystal-to-Single-Crystal Photopolymerization
- Northwestern Univ., Evanston, IL (United States); University of Notre Dame
- Univ. of California, Santa Cruz, CA (United States)
- Westlake Univ., Hangzhou (China)
- Northwestern Univ., Evanston, IL (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Tianjin Univ. (China)
- Tianjin Univ. (China); Univ. of New South Wales, Sydney, NSW (Australia); Northwestern Univ., Evanston, IL (United States)
The efficient preparation of single-crystalline ionic polymers and fundamental understanding of their structure–property relationships at the molecular level remains a challenge in chemistry and materials science. Herein, we observe the single-crystal structure of a highly ordered polycationic polymer (polyelectrolyte) and its proton conductivity. The polyelectrolyte single crystals can be prepared on a gram-scale in quantitative yield, by taking advantage of an ultraviolet/sunlight-induced topochemical polymerization, from a tricationic monomer—a self-complementary building block possessing a preorganized conformation. A single-crystal-to-single-crystal photopolymerization was revealed unambiguously by in situ single-crystal X-ray diffraction analysis, which was also employed to follow the progression of molecular structure from the monomer, to a partially polymerized intermediate, and, finally, to the polymer itself. Collinear polymer chains are held together tightly by multiple Coulombic interactions involving counterions to form two-dimensional lamellar sheets (1 nm in height) with sub-nanometer pores (5 Å). The polymer is extremely stable under 254 nm light irradiation and high temperature (above 500 K). The extraordinary mechanical strength and environmental stability—in combination with its impressive proton conductivity (~3 × 10–4 S cm–1)—endow the polymer with potential applications as a robust proton-conducting material. By marrying supramolecular chemistry with macromolecular science, the outcome represents a major step toward the controlled synthesis of single-crystalline polyelectrolyte materials with perfect tacticity.
- Research Organization:
- Univ. of Notre Dame, IN (United States); Univ. of California, Berkeley, CA (United States); Northwestern Univ., Evanston, IL (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); Army Research Office (ARO); National Natural Science Foundation of China (NSFC)
- Grant/Contract Number:
- NA0003763; AC02-05CH11231; FG02-08ER15967
- OSTI ID:
- 1603945
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 13 Vol. 142; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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