Sodium ion chemosensor of 3-oxo-3H-benzo[f]chromen-2-carboxylic acid: An experimental and computational study

Abstract

A fluorescence compound of benzocoumarin typical skeleton was synthesized and its interaction with various metal ions was evaluated. The synthesis was performed via Knoevenagel condensation whereas identification of the product was accomplished by various spectroscopic techniques. The chemo-sensor test against representative metal ions was monitored by fluorescence spectrophotometry. Density Functional Theory calculation (DFT) (Functional/basis set; M06/6-31G (d, p)) was also carried out to clarify the experimental results and to confirm the mechanism of interaction. The 3-oxo-3H-benzo[f]chromene-2-carboxylic acid 1 was obtained as yellow solid with; 60 % chemical yield, melting point; 235.6 - 236.7?C, ?max UV/Visible, ?em and Stokes shift (MeOH / nm); 374, 445, and 71 nm, respectively. Structure of the compound was identified based on spectroscopic data and literature comparison. The compound 1 exhibited a chelation quenched fluorescence (CHQF) phenomenon toward Na+ ion selectively, with binding stoichiometry (1:2) and LoD and LoQ of 0.14 and 0.48 mg/L, respectively. Based on DFT calculation, compound 1 chelated Na+ ion through mechanism of oxidative (1:1 equivalent) and reductive (2:1 equivalent) Photoinduced Electron Transfer (PET), correspondingly.

A new highly selective “off–on” typical chemosensor of Al3+, 1-((Z)-((E)-(3,5-dichloro-2-hydroxybenzylidene)hydrazono)methyl) naphthalene-2-ol, an experimental and in silico study

“…Comparatively, optical detection such as the uorescence method shows unique potential for high sensitivity. 19 At present, uorescent chemosensors have been widely used to detect different metal ions because of their high sensitivity, selectivity, and fast response time, 20,21 including to detect a trace of Al 3+ ions. Therefore, the development of an analytical method of Al 3+ ions based on uorescence detection is still interesting, in particular, to solve the issues of weak coordination ability of Al 3+ ions and its lack of spectroscopic characteristics.…”