Chemical Shift Standards for 199Hg NMR Spectroscopy, Twenty-Five Years Later

While mercury-199 NMR is a well-established tool for elucidating details of coordination chemistry in biochemical and inorganic complexes, historically the technique has been associated with the use of the extremely toxic chemical, dimethylmercury, as a reference standard. In the twenty-five years since an accidental exposure to dimethylmercury led to the tragic death of Dr. Karen Wetterhahn, the community has learned a great deal about the insidious neurotoxicity of this compound as well as more appropriate ways to avoid exposure. Here, we track the general shift towards the use of alternative mercury reference standards, and away from dimethylmercury.