COMPLEXATION OF METHYLMERCURY(II) BY DL-SELENOMETHIONINE

Abstract The complexation of metal ions by methionine [Met] has attracted considerable interest.1–3 However, the coordination chemistry of selenomethionine [Se-Met] has received much less attention despite the fact that it is one of the few naturally occuring selenoaminoacids and a component of at least one bacterial selenoenzyme.4 It has been shown by 1H NMR spectroscopy1 that the prototypical ‘soft’ metal ion, methylmercury(II), binds to Met above pH 7 via the amino group and binds to the thioether group at low pH. A single crystal X-ray diffraction study has confirmed amino coordination in a complex isolated from alkaline solution.5