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Fluoride anion sensing mechanism of 2‐(quinolin‐2‐yl)‐3‐hydroxy‐4 H ‐chromen‐4‐one chemosensor based on inhibition of excited state intramolecular ultrafast proton transfer
Author(s) -
Li Junyu,
Feng Shiquan,
Xu Liancai,
Feng Xuechao
Publication year - 2020
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.4116
Subject(s) - chemistry , intramolecular force , deprotonation , hydrogen bond , photochemistry , density functional theory , moiety , intermolecular force , time dependent density functional theory , molecule , excited state , fluoride , ion , computational chemistry , inorganic chemistry , stereochemistry , organic chemistry , atomic physics , physics
The excited state hydrogen bonding interactions and intramolecular proton transfer (ESIPT) process for 2‐(quinolin‐2‐yl)‐3‐hydroxy‐4 H ‐chromen‐4‐one (Qu3HC) system has been theoretically studied via density functional theory (DFT) and time‐dependent DFT (TDDFT) methods. We confirmed that the reversible tuning of intramolecular hydrogen bonding direction is impossible for Qu3HC system. Then, we have studied the S 0 ‐state and S 1 ‐state hydrogen bonding dynamical behaviors of Qu3HC structure and confirmed that the strengthening of intramolecular hydrogen bond in the S 1 state could facilitate ESIPT reaction. Given photo‐induced excitation, we find that the charge redistribution around hydroxyl moiety plays important roles in providing driving force for ESIPT. Our constructed potential energy curves further verify that the ESIPT process of Qu3HC should be ultrafast due to low potential barrier. With the addition of fluoride anions, the exothermal deprotonation process occurs spontaneously along with the intermolecular hydrogen bond O–H···F, which reveals the uniqueness of detecting fluoride anion using Qu3HC molecule. As a whole, the fluoride anion inhibits the initial ESIPT process of Qu3HC, which results in different fluorescence behaviors.