A highly selective ESIPT-based fluorescent probe with a large Stokes shift for the turn-on detection of cysteine and its application in living cells

Crystal structure of 4-(1-phenylimidazo[1,5-a]pyridin-3-yl)benzoic acid (C20H14N2O2)

“…The dihedral angles between the imidazole [1,5-a] pyridine moiety, the benzoic acid moiety, and the phenyl ring moiety are 27.3 and 29.9(9)°, respectively. The N pyridinyl -C benzoic acid , C benzoic acid -N imidazole and the N imidazole -C phenyl are similar to those of reported analogues [14,[21][22][23][24]…”

Towards NIR‐Active Hydroxybenzazole (HBX)‐Based ESIPT Motifs: A Recent Research Trend

“…ESIPT is photo‐induced tautomerization process in which the photoexcitation of ground state enol form yields an excited keto form (see Figure ). ESIPT molecules constitute an area of the very prolific field of research as they give large Stokes shifts and change in fluorescence due to keto‐enol tautomer . Due to unique photophysical properties, the ESIPT molecules have a wide range of application in sensing, laser dyes, photostabilizers, fluorescent probes in biology, and light emitting materials for the electroluminescent device.…”

An Excited State Intramolecular Proton Transfer-Based Fluorescent Probe with a Large Stokes Shift for the Turn-on Detection of Cysteine: A Detailed Theoretical Exploration

“… 11 − 20 Recently, a new fluorescent probe (2-(1-phenylimidazo[1,5-α]pyridine-3-yl)phenyl acrylate, denoted as MZC-AC) has been designed and synthesized to successfully recognize Cys in which only the HRMS and 1 H NMR spectra have been done to confirm the proposed excited state intramolecular proton transfer (ESIPT) mechanism. 21 Generally speaking, these spectroscopic techniques can only provide indirect information about the photochemical mechanisms. Additionally, the immanent reason why the isolated MZC-AC presents the state of fluorescence quenching is unclear.…”