Acid-Triggered Switchable Near-Infrared/Shortwave Infrared Absorption and Emission of Indolizine-BODIPY Dyes

Matthew A. Saucier; Cameron Smith; Nicholas A. Kruse; Nathan I. Hammer; Jared H. Delcamp

doi:10.3390/molecules28031287

Molecules (Jan 2023)

Acid-Triggered Switchable Near-Infrared/Shortwave Infrared Absorption and Emission of Indolizine-BODIPY Dyes

Matthew A. Saucier,
Cameron Smith,
Nicholas A. Kruse,
Nathan I. Hammer,
Jared H. Delcamp

Affiliations

Matthew A. Saucier: Department of Chemistry and Biochemistry, University of Mississippi, University, MI 38677, USA
Cameron Smith: Department of Chemistry and Biochemistry, University of Mississippi, University, MI 38677, USA
Nicholas A. Kruse: Department of Chemistry and Biochemistry, University of Mississippi, University, MI 38677, USA
Nathan I. Hammer: Department of Chemistry and Biochemistry, University of Mississippi, University, MI 38677, USA
Jared H. Delcamp: Department of Chemistry and Biochemistry, University of Mississippi, University, MI 38677, USA

DOI: https://doi.org/10.3390/molecules28031287
Journal volume & issue: Vol. 28, no. 3
p. 1287

Abstract

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Fluorescent organic dyes that absorb and emit in the near-infrared (NIR, 700–1000 nm) and shortwave infrared (SWIR, 1000–1700 nm) regions have the potential to produce noninvasive high-contrast biological images and videos. BODIPY dyes are well known for their high quantum yields in the visible energy region. To tune these chromophores to the NIR region, fused nitrogen-based heterocyclic indolizine donors were added to a BODIPY scaffold. The indolizine BODIPY dyes were synthesized via microwave-assisted Knoevenagel condensation with indolizine aldehydes. The non-protonated dyes showed NIR absorption and emission at longer wavelengths than an aniline benchmark. Protonation of the dyes produced a dramatic 0.35 eV bathochromic shift (230 nm shift from 797 nm to 1027 nm) to give a SWIR absorption and emission (λmaxemis = 1061 nm). Deprotonation demonstrates that material emission is reversibly switchable between the NIR and SWIR.

Published in Molecules

ISSN: 1420-3049 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Chemistry: Organic chemistry
Website: http://www.mdpi.com/journal/molecules

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