Synthesis of New ESIPT-Fluorescein: Photophysics of pH Sensitivity and Fluorescence

Abstract

ESIPT-inspired benzimidazolyl substituted fluorescein dyes were synthesized. PH-sensitivity was determined by the photophysical property measured at a physiological possible pH range. Fluorescence quantum efficiency values were calculated independently at two different emissions. A rational relationship is defined between fluorescence quantum efficiency and calculated HOMO energy.

ESIPT-inspired benzothiazole fluorescein: Photophysics of microenvironment pH and viscosity

“…We have reported in our earlier communication that incorporation of an ESIPT unit in fluorescein causes a red shift in emission to the tune of 50 nm as compared to that of the original fluorescein (570 nm) [18,19].…”

“…In continuation of our work in benzimidazole, oxazole and thiazole chemistry [14,19,20] and to understand the effect of ESIPT unit in the photophysical properties of fluorescein moiety, in this paper, we report the synthesis and photophysical properties of novel fluorescein molecules containing thiazole units. The photophysical properties are studied as a function of pH and viscosity.…”

Synthesis, crystal structure and DFT studies of a dual fluorescent ketamine: Structural changes in the ground and excited states

“…In the excited state the proton may be transferred from amine group (NH) to keto group (C=O) through ESIPT process leads to the existence of both KHB and EHB forms [18][19][20][21][22][23]33]. In dual emission, the low intensity peak at 410 nm arises from the normal ketamine form and the red shifted high intensity peak at 435 nm corresponds to the stable tautomeric enolimine form.…”

“…This hypothesis leads to the concept of twisted intramolecular charge transfer (TICT) process. A number of reports have shown that the degree of steric hindrance plays an important role in dual emission arises from twisted intramolecular charge transfer (TICT) or excited state intramolecular proton transfer (ESIPT) process [18][19][20][21][22][23].…”

Synthesis of novel fluorescent 1,3,5-trisubstituted triazine derivatives and photophysical property evaluation of fluorophores and their BSA conjugates

“…As a part of ongoing research to develop novel materials for high-tech applications (Sekar et al, 2010Gupta et al, 2011;Patil et al, 2012), here we report the synthesis, characterization, and photophysical properties of novel fluorescent biocompatible fluorophores and their binding study with protein. The novel triazine derivatives were prepared from 4-(4,6-dichloro-1,3,5-triazin-2-yl)-N,N -diethylaniline and different α -amino acids.…”