A Theoretical Study on the Fluorescence Signal Sensing of a colorimetric ClO^‐ chemosensor

Abstract

Detection of reactive oxygen species by optical signal sensing is of great interesting to the chemical and medical world. In this paper, the fluorescence signal sensing process of a colorimetric ClOchemosensor (S-BODIPY) has been investigated through DFT/TDDFT calculations. The relative free energy (ΔG = 23.46 kcal/mol) suggests that the oxidation process of the chemosensor by the analyte would have a favorable reaction rate, accounting for a rapid response speed, and the large binding energy of 35.3 kcal/mol supports a good selectivity of the chemosensor for ClO -. The calculated vertical excitation energies of S-BODIPY (1.93 eV) and its oxidation product SO-BODIPY (2.01 eV) agree well with the experimental emission data (2.00 and 2.11 eV, respectively). The absorption spectra and 1 H NMR spectra have also been computed and analyzed showing reasonably good agreement with experimental ones. The fluorescence signal sensing mechanism is verified to be associated with the intramolecular charge transfer (ICT), that is, the relatively weak ICT process in SO-BODIPY than that in S-BODIPY has caused the observable blueshift in both the absorption and emission spectra after the detection of ClO -. K E Y W O R D SClOcolorimetric chemosensor, Fluorescence sensing mechanism, Intramolecular charge transfer, Time-dependent density functional calculations, Oxidation reaction of thioether

Sensing Mechanism of Excited‐State Intermolecular Hydrogen Bond for Phthalimide: Indispensable Role of Dimethyl Sulfoxide

“…In a previous study, it was speculated that the remarkable fluorescence enhancement of PTI was attributed to the recovery of excited‐state intramolecular proton transfer (ESIPT) process, [ 30 ] where the proton transfer process between the proton donor and the proton receptor was adjacent to the excited molecule upon photoexcitation. [ 31‐38 ] However, we performed systematic theoretical calculations for the fluorescent probe CORM3‐green sensing process via density functional theory (DFT) and time dependent DFT (TDDFT) methods. Among them, we provided a new strategy for the reduction product PTI through the analyses of the detailed bond parameters (dihedral angle and bond length), the reduced density gradient function, IR spectra and molecular orbitals.…”

Fluoride ion‐induced gas sensor based on the dipyrromethene boron difluoride derivative: A theoretical investigation

“…Few studies on the sensor mechanism of BODIPYs toward the gases are available. [27][28][29] Based on these considerations, I present a BODIPY derivative, namely, 1,3,7-trimethyl-5-phenylamino-BODIPY (hereafter referred to as BNDP, Scheme 1), and theoretically investigate the ability of the deprotonated BNDP as a fluorescent probe toward gases, that is, CO 2 , COS, SO 2 , SO 3 , H 2 S, and NH 3 . The BODIPY core and the N atom of the phenylamino group play the roles of response signal unit and binding site, respectively.…”