Indolizine-Cyanine Dyes: Near Infrared Emissive Cyanine Dyes with Increased Stokes Shifts
Molecular engineering strategies designed to red-shift cyanine dye absorptions and emissions further into the near-infrared (NIR) spectral region are explored. Through the use of a novel donor group, indolizine, with varying cyanine bridge lengths, dye absorptions and emissions, were shifted deeper...
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Published in | Journal of organic chemistry Vol. 84; no. 2; pp. 687 - 697 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
18.01.2019
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | Molecular engineering strategies designed to red-shift cyanine dye absorptions and emissions further into the near-infrared (NIR) spectral region are explored. Through the use of a novel donor group, indolizine, with varying cyanine bridge lengths, dye absorptions and emissions, were shifted deeper into the NIR region than common indoline-cyanines. Stokes shifts resulting from intramolecular steric interactions of up to ∼60 nm in many cases were observed and explained computationally. Molecular brightnesses of up to 5800 deep into the NIR region were observed. Structure–property relationships are explored for the six indolizine-cyanine dyes with varying cyanine bridge length and indolizine substituents showing broad absorption and emission tunability. The dyes are characterized by crystallography, and the photophysical properties are probed by varying solvent for absorption and emission studies. Computational data show involvement of the entire indolizine π-system during light absorption, which suggests these systems can be tunable even further into the NIR region through select derivatizations. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/acs.joc.8b02521 |