The redox interaction between the vanadyl cation and tris[6-(2-hydroxymethyl)pyridylmethyl]amine

Reaction of tris[6-(2-hydroxymethyl)pyridylmethyl]amine, tpa(OH)3, with VIVOSO4·5H2O resulted in an unexpected redox reaction producing [VIIILH][VIIILH2][PF6]3·1.5H2O (where H3L is bis(2-hydroxymethylpyridyl)(2-carboxypyridylmethyl)amine). This reaction is interesting in the light of the ability of ascidians to accumulate VIII by reduction of VV from sea water. It also provides additional proof to the susceptibility of pyridylmethylamines to oxidation by certain metal ions.

Graphical abstractReaction of tpa(OH)3 with VIVOSO4·5H2O resulted in a redox reaction producing [VIIILH][VIIILH2][PF6]3·1.5H2O.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Reaction of the vanadyl cation, {VIVO}2+, with a polypyridyl ligand. ► A VIII complex containing an oxidized form of the ligand is formed. ► NMR spectroscopy indicates catalytic aerial oxidation of the ligand by VOSO4.