Sendh J, Baruah JB. Sequential effects of two cations on the fluorescence emission of a coordination polymer with Zn
4O core in node.
RSC Adv 2024;
14:31598-31606. [PMID:
39376515 PMCID:
PMC11457270 DOI:
10.1039/d4ra06309k]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2024] [Accepted: 09/26/2024] [Indexed: 10/09/2024] Open
Abstract
Distinct changes in the fluorescence emissions of free ligand 5-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)isophthalic acid (H2NAPHISO) than a 2D-zinc-coordination polymer of it, caused by sequential interactions with different sets of binary cations were observed. The coordination polymer having unsymmetrical Zn4O core of tetranuclear zinc-node could be dispersed in dimethylformamide without its degradation. The coordination polymer had an emission peak at 435 nm (quantum yield = 0.082) which was selectively quenched by adding Fe2+ ions. Based on this quenching, the Fe2+ ions in aqueous solution could be detected with a detection limit 42.57 nM. The metal ions such as Li+, Na+, Cd2+, Hg2+, Al3+ did not interfere in the detection; but each of these ions together with Fe2+ ions showed characteristic shift of the emission spectra. The H2NAPHISO in dimethyl formamide was non-fluorescent, but showed emission at 452 nm upon addition of Cd2+ or Zn2+ ions. This new emission of H2NAPHISO caused by zinc or cadmium ions was not quenched by Fe2+ ions. Various cations had affected the emission of the H2NAPHISO with Zn2+ which was much different from the corresponding changes caused by the same ion on the emission of the coordination polymer. For example, the Mn2+ and Zn2+ ions together in a solution of the ligand showed a broad emission spectrum spreading over 380-450 nm, but ions Sn2+ and Zn2+ together had showed emission at a shorter wavelength (380 nm). These allowed to modulate the emission of the ligand by binary combination of metal ions.
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