Formation and catalytic activity of novel water soluble di[ethylenediaminetetraacetato bis(N-oxido)] lanthanides

•Reaction of hydrogen peroxide and edta lanthanide forms N-oxido edta lanthanide.•Water-soluble N-oxido edta lanthanide fully dissociates in solution.•N-oxido edta lanthanide catalyzes the conversion of pyridine to pyridine N-oxide in 96% yield.

Reaction of hydrogen peroxide with ethylenediaminetetraacetato lanthanides results in the formation of water-soluble isomorphous N-oxido ethylenediaminetetraacetato lanthanides K5[Ln(edtaO2)2] · 12H2O [Ln = La (1), Ce (2), Nd (3), H4edta = ethylenediaminetetraacetic acid C10H16O8N2] in weak basic solution, where lanthanide ions are octa-coordinated by two quardentate N-oxido edta ligands, resulting in a distorted anti-tetragonal prism. Based on the comparisons of solid and solution 13C NMR spectra, these compounds are fully dissociated in solution. Catalytic reaction of K5[La(edtaO2)2]·12H2O shows 96% conversion for the reaction of pyridine to pyridine N-oxide at 70 °C.

Graphical abstractLanthanum N-oxido ethylenediaminetetraacetate catalyzes the oxidation of pyridine with hydrogen peroxide with a yield of 96%. Peroxo groups are trapped by ethylenediaminetetraacetate.Figure optionsDownload full-size imageDownload as PowerPoint slide