Synthesis of spiro-oxindole-based chemosensor for detection of Hg2+ ions using SBA-Pr-N-IS-Bu-SO3H

• Published in: Inorganic chemistry communications 2024-06, Vol.164, p.112398, Article 112398
• Main Authors: Mohammadi Ziarani, Ghodsi, Panahande, Zahra, Badiei, Alireza
• Format: Article
• Language: English
• Subjects: Hg2+ ions chemosensors; Multicomponent reaction; SBA-Pr-N-IS-Bu-SO3H; Spiro-oxindoles
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2024.112398

[Display omitted] •Spiro-oxindoles was prepared using SBA-Pr-N-Is-Bu-SO3H as nanocatalyst via the reaction of isatin, malononitrile, and dimedone with high efficiency.•The sensing properties were appraised in EtOH for the various metals cations.•The result revealed that compound 4d could be used as chemosensors for the sensitive detection Hg2+ ion using fluorescence spectroscopy.•The detection limit was calculated to 4.6 × 10−7 M for Hg2+.•The stoichiometric ratio of ligand with Hg2+ ion, Job’s plot test was performed and the ratio was 2:3. Spiro-oxindoles were prepared efficiently via multicomponent reactions (MCRs) for finding the new chemosensors. Also, the use of the efficient nanocatalysts based on SBA-15 in these reactions are so important. Therefore, the functionalization of SBA-15 by different organic compounds are common to produce new efficient nanocatalysts. Herein, SBA-Pr-N-Is-Bu-SO3H as an efficient nanoporous catalyst was applied in the synthesis of (5,6,7,8-tetrahydro-chromene)-4,3′-spirocyclic oxindoles through the three-component reaction of isatin derivatives, malononitrile and dimedone under reflux conditions in high yield and short reaction time. Among all spiro-oxindole derivatives, 2-amino-7,7-dimethyl-5′-nitro-2′,5-dioxo-5,6,7,8-tetrahydro-spiro[chromen-4,3′-indoline]-3-carbonitrile was investigated in fluoresence spectroscopy. According to the obtained results it was observed that in the presence of various cations such as, K+, Ca2+, Na+, Cu2+, Zn2+, Cr3+, Fe3+, Fe2+, Mn2+, Co2+, Al3+, Pb2+, Ag+, Cd2+, Ni2+, Hg2+ and Mg2+, it can selectively detect Hg2+ ion and increase the emission intensity. Its calculated detection limit was 4.6 × 10−7 M, which can be considered a good value. Also, in order to determine the stoichiometric ration for ligand and Hg2+ ion, Job's plot test was performed and the ratio was 1:2.