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The platinum(II) complexes of known quinoline-annulated porphyrins were prepared and spectroscopically characterized. Their optical properties (UV-vis absorption and phosphorescence spectra and phosphorescence lifetimes) were recorded and contrasted against their 2,3-dioxoporphyrin precursor platinum(II) complex. The absorbance and emission spectra (in EtOH glass at 77 K) of the quinoline-annulated porphyrins fall within the NIR optical window of tissue, ranging, depending on the derivative, between [Formula: see text]950 and 1200 nm. The much red-shifted optical spectra, when compared to their non-quinoline-annulated precursors, are attributed to the [Formula: see text]-extension and conformational non-planarity that the annulation causes. The emission yields of the mono-quinoline-annulated derivatives are too low and their lifetimes too short to be practical emitters, but the bis-annulated derivative possesses a practical lifetime and emission yield, suggesting its further exploration, particularly since the methodology toward the solubilization of the quinoline-annulated porphyrins in biological media through derivatization is known.
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S N Ar Reaction Toward the Synthesis of Fluorinated Quinolino[2,3,4‐at]porphyrins
Abstract An intramolecular SNAr displacement of oneo‐fluorine atom of ameso‐pentafluorophenyl‐substituted porphyrin metal complex by a neighboring β‐amino functionality generated the correspondingmeso‐fluorophenyl‐substituted metallo‐quinolino[2,3,4‐at]porphyrins that are not accessible using established quinoline‐annulation methodologies. The Cu(II), Ni(II), and Zn(II) complexes were thus prepared. The parent free base quinolino[2,3,4‐at]porphyrin is accessible only by demetallation of the copper or zinc complexes. A strong through‐space NMR‐spectroscopic coupling between the remainingo‐fluorine atoms on the annulatedmeso‐aryl group and the β‐hydrogen atom on the adjacent pyrrole moiety provide a clear spectroscopic signature for the annulation. Quinoline‐annulation alters the optical properties significantly. On account of the presence of the β‐amino functionality, all quinoline‐annulated porphyrins show strong halochromic responses with Brønsted acids and bases, the prerequisite for their potential use in chemosensing applications.
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- Award ID(s):
- 1800361
- PAR ID:
- 10238454
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- European Journal of Organic Chemistry
- Volume:
- 2021
- Issue:
- 2
- ISSN:
- 1434-193X
- Format(s):
- Medium: X Size: p. 318-323
- Size(s):
- p. 318-323
- Sponsoring Org:
- National Science Foundation
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