Three-Dimensional Fully Conjugated Carbaporphyrin Cage

Xian Sheng Ke, Taeyeon Kim, Qing He, Vincent M. Lynch, Dongho Kim, Jonathan L. Sessler

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

A fully conjugated three-dimensional (3D) expanded carbaporphyrin (2) was prepared in a one-pot procedure that involves a [2+4] condensation reaction between a dibenzo[g,p]chrysene-bearing tetrapyrrole precursor (1) and pentafluorobenzaldehyde, followed by oxidation. Single crystal X-ray diffraction analysis revealed that 2 possesses a cage-like structure consisting of four dipyrromethenes and two bridging dibenzo[g,p]chrysene units. As prepared, 2 is nonaromatic as inferred from UV-vis-NIR and 1 H NMR spectroscopy and a near-zero (1.75) nucleus-independent chemical shift (NICS) value. In contrast, after protonation with trifluoroacetic acid (TFA), the cage gains global aromatic character as inferred from the large negative NICS value (11.63) and diatropic ring current observed in the anisotropy of the induced current density (ACID) plot, as well as the ca. 8-fold increase in the excited state lifetime. In addition, the size of the cavity increases to ca. 143 Å 3 upon protonation as deduced from a single crystal X-ray diffraction analysis. To our knowledge, this is the largest carbaporphyrin prepared to date and the first with a fully conjugated 3D cage structure whose size and electronic features may be tuned through protonation.

Original languageEnglish
Pages (from-to)16455-16459
Number of pages5
JournalJournal of the American Chemical Society
Volume140
Issue number48
DOIs
Publication statusPublished - 2018 Dec 5

All Science Journal Classification (ASJC) codes

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

Fingerprint Dive into the research topics of 'Three-Dimensional Fully Conjugated Carbaporphyrin Cage'. Together they form a unique fingerprint.

  • Cite this

    Ke, X. S., Kim, T., He, Q., Lynch, V. M., Kim, D., & Sessler, J. L. (2018). Three-Dimensional Fully Conjugated Carbaporphyrin Cage. Journal of the American Chemical Society, 140(48), 16455-16459. https://doi.org/10.1021/jacs.8b11158