 The first organocadmium compounds, dimethylcadmium, CH3-Cd-CH3, and diethylcadmium, CH3CH2-Cd-CH2CH3, were prepared in 1917 by Erich Krause.In general, they are prepared by transmetalation or by an exchange reaction between an organometallic reagent and a cadmium salt.One procedure for the synthesis of diethylcadmium is by the reaction of cadmium bromide with two equivalents of the Grignard reagent ethylmagnesium bromide in diethyl ether.