Emissive single-crystalline boroxine-linked colloidal covalent organic frameworks

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

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


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. 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.

Original languageEnglish
Pages (from-to)19728-19735
Number of pages8
JournalJournal of the American Chemical Society
Issue number50
Publication statusPublished - Dec 18 2019

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Emissive single-crystalline boroxine-linked colloidal covalent organic frameworks'. Together they form a unique fingerprint.

Cite this