A novel selective fluorescent chemosensor for Fe3+ ions based on phthalonitrile dimer: synthesis, analysis, and theoretical studies

Abstract

Phenyl-4,4-di(3,6-dibutoxyphthalonitrile) (3) was synthesized by the reaction of 1,4-phenylenebisboronic acid (1) and 4-bromo-3,6-dibutoxyphthalonitrile (2), using Suzuki cross-coupling reaction. The newly synthesized compound (3) was characterized by FT-IR, MALDI-MS, ESI-MS, 1H-NMR, 13C-NMR, and 13C-DEPT-135-NMR. The fluorescence property of phenyl-4,4-di(3,6- dibutoxyphthalonitrile) (3) towards various metal ions was investigated by fluorescence spectroscopy, and it was observed thatthe compound (3) displayed a significantly ‘turn-off’ response to Fe3+, which was referred to 1:2 complex formation between ligand (3) and Fe3+. The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe3+ ions.

Rapid Synthesis of Phthalonitrile based Push‐Pull Bent Dibenzodioxin and its Utility in Selective Sensing of Ferric Ions

“…Photostability test of bent dibenzodioxin (50 μM) was done in DMSO over 60 minutes. Figure 4 shows that the emission remained almost constant and did not decrease with time, hinting towards the stability of the emission of the compound [11] …”

“…The fluorimetric titration of bent dibenzodioxin with Fe 3+ solution showed a decrease in fluorescence intensity by increasing the concentration of Fe 3+ ion. The Job's plot is illustrated in Figure 9, which shows a maximum when the mole fraction of Fe 3+ ion reaches 0.6, indicating 1 : 2 stoichiometry complexation between bent dibenzodioxin and Fe 3+ ion in DMSO [10b,11] …”

“…Figure 4 shows that the emission remained almost constant and did not decrease with time, hinting towards the stability of the emission of the compound. [11]…”

Performance of 4,5‐diphenyl‐1H‐imidazole derived highly selective ‘Turn‐Off’ fluorescent chemosensor for iron(III) ions detection and biological applications

“…The process involved refluxing precursor compounds, benzyl, and ammonium acetate in a heated glacial acetic acid mixture. The synthesis of the chemosensors was accomplished with a quantitative yield, and their characterization was performed using various techniques, including FTIR, 1 H-, 13 C-NMR, and ESI mass spectrometry (refer to Supporting Information Figures S1-S4). The spectral analysis, along with consistent data, provided confirmation of the structures of chemosensors 1 and 2.…”

“…The developed chemosensors exhibit a distinct 'On-Off' fluorescence response specifically to iron(III) ion (Fe 3+ ). Iron, a prevalent transition metal in the human body, plays a crucial role in electron transport within the heme enzyme complex, essential for life's energy conversion [13,14]. Iron ions are vital for oxygen transport in hemoglobin, various metabolic processes, and storage and utilization of oxygen in muscles.…”