The only products that could be definitely assigned as resulting from the methylation of MEA were DEA and Ch (7% yield and trace (<1%), respectively, based on conversion of MEA, of which 88% remained). The assignments of DEA and Ch were made by comparison with spectroscopic standards of each molecule in aqueous phosphate buffer at pH 7.4. Several additional products (4% in total, based on conversion of MEA) were also formed but these could not be definitively assigned. Products resulting from the methylation of nucleophiles other than MEA (namely ferrocyanide (a product of the system), water, and cyanide) included [Fe(CN) 5 CNMe] 3-, methanol, and acetonitrile (see above).