4-Quinolone-Carboxamide and Carbothioamide Compounds as Fluorescent Sensors. New Fluorimetric Methods for Cu2+ and Fe3+ Determination in Tap Water and Soil

Ion sensor properties of the carboxamide and carbothioamide compounds carrying 4-quinolone group were investigated by means of emission spectrometry in methanol-water (1:1). The compounds were selectively complexed with Cu²⁺, Pd²⁺, and Fe³⁺ among many metal ions. The complex stoichiometry and the stability constant were determined by fluorimetric measurements. The carboxamide compound having phenyl group (QPO) showed sensitivity for Fe³⁺ ion with a linear range between 0.1 and 0.7 mg/L. The new method was applied in the determination of iron in the spiked tap water samples and the sandy-soil reference material. A modified standard addition method was used to remove the matrix effect. Limit of detection was 0.03 mg/L for the Fe³⁺ determination method. The carboxamide compound with benzyl group (QBO) showed sensitivity for Cu²⁺ ion with linear range 0-0.4 mg/L. There was no matrix effect for copper determination in the spiked tap water samples. The detection limit of the method for Cu²⁺ ion was 0.05 mg/L. The quantification limits of the methods were low enough to determine iron and copper amount in drinking water samples according to EPA.

Molecular iron complexes as catalysts for selective C–H bond oxygenation reactions

This feature article summarises recent developments in homogeneous C–H bond oxygenation catalysed by molecular iron complexes.