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

Abstract

Reaction of hydrogen peroxide with ethylenediaminetetraacetato lanthanides results in the formation of water-soluble isomorphous N-oxido ethylenediaminetetraacetato lanthanides K 5 [Ln(edtaO 2 ) 2 ] · 12H 2 O [Ln = La ( 1 ), Ce ( 2 ), Nd ( 3 ), H 4 edta = ethylenediaminetetraacetic acid C 10 H 16 O 8 N 2 ] 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 13 C NMR spectra, these compounds are fully dissociated in solution. Catalytic reaction of K 5 [La(edtaO 2 ) 2 ]·12H 2 O shows 96% conversion for the reaction of pyridine to pyridine N-oxide at 70 °C. Lanthanum N-oxido ethylenediaminetetraacetate catalyzes the oxidation of pyridine with hydrogen peroxide with a yield of 96%. Peroxo groups are trapped by ethylenediaminetetraacetate. • 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.