Emissive Single-Crystalline Boroxine-Linked Colloidal Covalent Organic Frameworks

Journal Article · 19 November 2019 · Journal of the American Chemical Society

DOI: https://doi.org/10.1021/jacs.9b08815 · OSTI ID:1630069

Evans, Austin M.  ^[1]; Castano, Ioannina  ^[1]; Brumberg, Alexandra  ^[1]; Parent, Lucas R.  ^[1]; Corcos, Amanda R.  ^[1]; Li, Rebecca L.  ^[1]; Flanders, Nathan C.  ^[1]; Gosztola, David J.  ^[2]; Gianneschi, Nathan C.  ^[1]; Schaller, Richard D.  ^[2]; Dichtel, William R.  ^[1]

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1. Northwestern Univ., Evanston, IL (United States)
2. Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials

The synthesis of periodic two-dimensional (2D) polymers and characterization of their optoelectronic behaviors are challenges at the forefront of polymer chemistry and materials science. Recently, we showed that layered 2D polymers known as 2D covalent organic frameworks (COFs) can be synthesized as single crystals by preparing COF particles as colloidal suspensions. Here we expand this approach from the condensation of boronic acids and catechols to the dehydrative trimerization of polyboronic acids. The resulting boroxine-linked colloids are the next class of 2D COFs to be obtained as single-crystalline particles, as demonstrated here for four 2D COFs and one 3D COF. Colloidal stabilization enables detailed structural analysis by synchrotron X-ray diffraction and high-resolution transmission electron microscopy. Solution fluorescence spectroscopy revealed that the COF crystallites are highly emissive compared to their respective monomer solutions. Excitation-emission matrix fluorescence spectroscopy indicated that the origin of this enhanced emission can be attributed to through-space communication of chromophores between COF sheets. Finally, these observations will motivate the development of colloidal COF systems as a platform to organize functional aromatic systems into precise and predictable assemblies with emergent properties.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; National Institutes of Health (NIH); National Science Foundation (NSF); US Army Research Office (ARO)
• Grant/Contract Number: AC02-06CH11357; W911NF-15-1-0447; DGE-1324585; DMREF-1629383; DGE-1842165
• OSTI ID: 1630069
• Journal Information: Journal of the American Chemical Society, Vol. 141, Issue 50; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
covalent organic frameworks
monomers
nanoparticles
two dimensional materials
physical and chemical processes