Retraction: Synthesis and characterization of novel silica-coated magnetic nanoparticles with tags of ionic liquid. Application in the synthesis of polyhydroquinolines

Abstract

Retraction of ‘Synthesis and characterization of novel silica-coated magnetic nanoparticles with tags of ionic liquid. Application in the synthesis of polyhydroquinolines’ by Mohammad Ali Zolfigol et al., RSC Adv., 2015, 5, 103617–103624, https://doi.org/10.1039/C5RA23670C.

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The Royal Society of Chemistry hereby wholly retracts this RSC Advances article as the synthesis of {Fe₃O₄@SiO₂@(CH₂)₃Im}C(CN)₃ reported in the article, whereby tricyanomethane is used as a starting material, is not reproducible. The authors stated that they did not report the synthesis of tricyanomethane in the published paper as they purchased this compound from a commercial center and used it in the synthesis of ionic liquids, molten salts and various kinds of catalysts. The authors thought the reaction between tricyanomethane and organic bases is a simple acid–base reaction, therefore they did not cite the previously reported literature and its related history for the preparation of tricyanomethane. However, according to papers by Banert et al.,^1,2 and based on their obtained analysis of the chemical sold to them as tricyanomethane, it became clear to the authors that this purchased compound was not tricyanomethane as there were differences in the ¹H NMR and ¹³C NMR chemical shift of the purchased compound and the reports of Banert et al.¹ According to these documents, the authors believe that the compound sold to them as tricyanomethane was fake. While the authors have now re-prepared {Fe₃O₄@SiO₂@(CH₂)₃Im}C(CN)₃, by synthesising potassium tricyanomethanide as a starting material for the synthesis,^3–5 the synthesis reported in this article is not accurate. Therefore, this article is being retracted to avoid misleading readers and to protect the accuracy and integrity of the scientific record.

Mohammad Ali Zolfigol and Meysam Yarie oppose the retraction.

Signed: Laura Fisher, Executive Editor, RSC Advances

Date: 17^th August 2022

References

1. K. Banert and M. Hagedorn, Synlett, 2019, 30, 1427.
2. K. Banert, M. Chityala, M. Hagedorn, H. Beckers, T. Stueker, S. Riedel, T. Rueffer and H. Lang, Angew. Chem., Int. Ed., 2017, 56, 9582.
3. S. Trofimenko, E. L. Little and H. F. Mower, J. Org. Chem., 1962, 27, 433.
4. R. A. Carboni, Org. Synth., 1959, 39, 64.
5. R. C. Beaumont, K. B. Aspin, T. J. Demas, J. H. Hoggatt and G. E. Potter, Inorg. Chem. Acta, 1984, 84, 141.

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