Molecular Engineering of Stabilized Silicon-Rosindolizine Shortwave Infrared Fluorophores.
J Org Chem
; 89(5): 2825-2839, 2024 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-38334085
ABSTRACT
Fluorescence-based biological imaging in the shortwave infrared (SWIR, 1000-1700 nm) is an attractive replacement for modern in vivo imaging techniques currently employed in both medical and research settings. Xanthene-based fluorophores containing heterocycle donors have recently emerged as a way to access deep SWIR emitting fluorophores. A concern for xanthene-based SWIR fluorophores though is chemical stability toward ambient nucleophiles due to the high electrophilicity of the cationic fluorophore core. Herein, a series of SWIR emitting silicon-rosindolizine (SiRos) fluorophores with emission maxima >1300 nm (up to 1550 nm) are synthesized. The SiRos fluorophore photophysical properties and chemical stability toward nucleophiles are examined through systematic derivatization of the silicon-core alkyl groups, indolizine donor substitution, and the use of o-tolyl or o-xylyl groups appended to the fluorophore core. The dyes are studied via absorption spectroscopy, steady-state emission spectroscopy, solution-based cyclic voltammetry, time-dependent density functional theory (TD-DFT) computational analysis, X-ray diffraction crystallography, and relative chemical stability over time. Optimal chemical stability is observed via the incorporation of the 2-ethylhexyl silicon substituent and the o-xylyl group to protect the core of the fluorophore.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
J Org Chem
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos