<unk>  currently has few applications because of the risks involved. As with many methyl-organometallics, it is a methylating agent that can donate its methyl groups to an organic molecule; however, the development of less toxic nucleophiles such as dimethylzinc, trimethylaluminium, and Grignard reagents (organomagnesium halides), has essentially rendered this compound obsolete in organic chemistry. It was also studied for reactions involving bonding methylmercury cations to target molecules, forming potent bactericides, but methylmercury's bioaccumulation and ultimate toxicity has led it to be largely abandoned in favor of the less toxic ethylmercury and<unk>  compounds, which perform a similar function without the bioaccumulation hazard. In toxicology, it still finds limited use as a reference toxin. It is also used to calibrate NMR instruments for detection of mercury (δ 0 ppm for 199Hg NMR), although<unk>  and less toxic mercury salts are now preferred.
Dimethylmercury
Ethylmercury
Mercury
Vinyl chloride
Metaldehyde
Lewis lead
Hydrogen fluoride
Heptachlor