Azaneylylidene-based tetradentate Schiff base as a new “ON-OFF” fluorescent probe for the detection of Cu(II) ion: Synthesis, characterization and real sample analysis

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 292; p. 122435
• Main Authors: Divyashree, N.R., Revanasiddappa, H.D., Bhavya, N.R., Mahendra, M., Jayalakshmi, B., Shivamallu, Chandan, Prasad Kollur, Shiva
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.05.2023
• Subjects: Chemosensor; Cu(II) ion; DFT; Fluorescence quenching; Chemosensor; Cu(II) ion; DFT; Fluorescence quenching
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2023.122435

[Display omitted] •2,2′-((1E,1′E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methane-ylylidene))bis(4-bromophenol) as Cu(II) probe.•Tap and lake water analysis.•Limit of detection was found to be 0.302 μM. Herein we describe the synthesis of Cu2+ sensor, 2,2′-((1E,1′E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methane-ylylidene))bis(4-bromophenol) (CPMB) and characterization using various spectral and analytical techniques. CPMB exhibited high selectivity towards Cu2+ ions via fluorescence quenching mechanism, which combined the character of high selectivity towards Cu2+ assay even in the presence of other common metal ions such as Cu2+, Al3+, Co2+, Ni2+, Mn2+, Zn2+ Pb2+ Cd2+, Fe2+, Hg2+, Mg2+ and Fe3+ (30 μM) ethanol-water (1:9 v/v) system. Upon the addition of the solution of Cu2+ ions to CPMB, the complexation of Cu2+ with CPMB leads to the immediate formation of light green color, indicating that CPMB can act as simple colorimetric sensor, particularly for Cu2+ in the presence of most interfering metal ions in ethanol-water medium. More interestingly, the ability of sensing behavior of CPMB for Cu2+ ion in the real water samples (tap water and lake water samples) was also investigated. Further, Job’s plot confirmed that the complexation occurred in 1:1 ratio (ligand:metal). Furthermore, the fluorescence inhibiting factor showed a good linear relationship with the concentration of Cu2+ with detection limit of 0.302 μM. The electronic transitions of the complex in ethanol were studied using DFT calculations.