Fluorescence switching of imidazo[1,5-a]pyridinium ions: pH-sensors with dual emission pathways.
Imidazo[1,5-a]pyridinium ions are identified as highly emissive and water-soluble fluorophores accessed by an efficient three-component coupling reaction. Synthetic modifications of groups conjugated to the polyheterocyclic core are shown to profoundly impact the emission properties of these molecules. Notably, two structural isomers of functionalized imidazo[1,5-a]pyridinium ions were found to exhibit distinct de-excitation pathways, which are responsible for either a fluorescence turn-on or ratiometric response to pH change.
Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA.
Johnathon T
JT
Hutt
Junyong
J
Jo
András
A
Olasz
Chun-Hsing
CH
Chen
Dongwhan
D
Lee
Zachary D
ZD
Aron
D002412:Cations / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*
D002412:Cations; D005456:Fluorescent Dyes; D011725:Pyridines; D011726:Pyridinium Compounds; C554655:imidazo(1,5-a)pyridine