26 research outputs found
ChemInform Abstract: Novel Rhodamine Dyes via Suzuki Coupling of Xanthone Triflates with Arylboroxins.
Coumarin‐Pyronin Hybrid Dyes: Synthesis, Fluorescence Properties and Theoretical Calculations**
Synthesis and Properties of Heavy Chalcogen Analogues of the Texas Reds and Related Rhodamines
Analogues
of Texas red incorporating the heavy chalcogens S, Se,
and Te atoms in the xanthylium core were prepared from the addition
of aryl Grignard reagents to appropriate chalcogenoxanthone precursors.
The xanthones were prepared via directed metalation of amide precursors,
addition of dichalcogenide electrophiles, and electrophilic cyclization
of the resulting chalcogenides with phosphorus oxychloride and triethylamine.
The Texas red analogues incorporate two fused julolidine rings containing
the rhodamine nitrogen atoms. Analogues containing two “half-julolidine”
groups (a trimethyltetrahydroquinoline) and one julolidine and one
“half-julolidine” were also prepared. The photophysics
of the Texas red analogues were examined. The S-analogues were highly
fluorescent, the Se-analogues generated single oxygen (<sup>1</sup>O<sub>2</sub>) efficiently upon irradiation, and the Te-analogues
were easily oxidized to rhodamines with the telluroxide oxidation
state. The tellurorhodamine telluroxides absorb at wavelengths ≥690
nm and emit with fluorescence maxima >720 nm. A mesityl-substituted
tellurorhodamine derivative localized in the mitochondria of Colo-26
cells (a murine colon carcinoma cell line) and was oxidized <i>in vitro</i> to the fluorescent telluroxide