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.

In Silico DFT (Density Functional Theory) Study of Chemosensor Selectivity of 3-Oxo-3H-Benzo[f]chromen-2-Carboxylic Acid (ABKK) on Sodium Metal Ion Using FMO (Frontier Molecular Orbital) Analysis

“…The materials used in this study were the ABKK structure model and several representative models of valence metal ions of 1, 2, and 3, including Na + , K + , Li + , Mg 2+ , Ni 2+ , Cu 2+ , and Al 3+ ions. The type of metal ions was selected based on the laboratory test results [2] and the basis set's limitations. DFT calculation was performed on a PC with Intel®Xeon(R) Processor CPU E5-2650 v2@2.60 GHz ×32, 16 GB RAM, with Gaussian 09 software [19].…”

“…The structure of the ABKK chemosensor and its chelate compound with Na + , K + , Li + , Mg 2+ , Ni 2+ , Cu 2+ , and Al 3+ metal ions was optimized at 1:1 and 2:1 ratios under non-solvent conditions using the DFT at the level of M06 method with a basis set of 6-31G (d, p) [3,19]. The optimization ratio of ABKK to metal ions was based on the results of fluorimetric titration of ABKK with metal ions in the laboratory [2]. Next, the electronic properties of the molecular orbital of ABKK and its chelates with metal ions were analyzed.…”

“…Chemosensors are sensor-type chemical compounds that can provide accurate information in real-time about the presence of specific compounds or ions in even complex samples. Metal ion chemosensors based on fluorescent compounds work by chelating metal ions contained in the analyte, thus forming a complex followed by changes in fluorescence intensity that can be monitored by spectrofluorometry [1,2]. Among several metal analysis techniques, chemosensors have advantages over other methods, including low cost, convenience, and fast response [3,4,5,6].…”

“…One of the organic compounds that can be used as chemosensors is coumarin derivatives, which have advantages such as large Stockes shift, high fluorescent quantum yield, good light stability, absorption and emission profile in visible light regions, and non-toxic [18]. Among the many coumarin-derived compounds that have been successfully reported as selective and sensitive chemosensors to Na + metal ion was 3-oxo-3Hbenzo[f]chromen-2-carboxylic acid (ABKK) with an "on-off" chemosensor model through fluorescence quenching by oxidative and reductive PET [2].…”

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.…”