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Updated: May 7, 2026

Quantifiable and Inexpensive Cell-Free Fluorescent Method to Confirm the Ability of Novel Compounds to Chelate Iron
Published on: February 23, 2024
Iron and manganese pyridoxal-based complexes as fluorescent probes for nitrite and nitrate anions in aqueous solution
Maria Strianese1, Stefano Milione, Valerio Bertolasi
1Dipartimento di Chimica, Università di Salerno , via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy.
Abstract:
Water-soluble iron and manganese pyridoxal-based complexes pyr2enFeCl (1) and pyr2enMnCl (2) (pyr2en = N,N'-ethylenebis(pyridoxylideneiminato) have been synthesized and characterized. Proof-of-principle results that the title complexes can be efficiently used as fluorescent probes for nitrite and nitrate detection are provided. The fluorescent complex pyr2enFeCl (1) selectively recognizes nitrate anions by fluorescent enhancement in an aqueous solution displaying high binding affinities. ESI-MS experiments clearly show the binding of these anions via the substitution of the chloride anion at the metal center. The pyridoxal-based manganese complexes of NO2(-) and NO3(-) have been isolated, and their structures have been established by single-crystal XRD. Density functional theory (DFT) calculations show that the substitution of the chloride anion at the metal center by the nitrite or nitrate anion is favored by the gain in the energies of hydration.
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