Dimethyl cuprate undergoes C-C bond coupling with methyliodide in the gas phase but dimethyl argenate does not

Multistage mass spectrometry experiments have been used to synthesize and study the reactions of (CH3)2M-(M = Cu and Ag) with methyl iodide in the gas phase. While the dimethylcuprate ion (M = Cu) reacts with CH3I via C-C bond cross coupling, its silver congener is unreactive. The experimental results are consistent with MP2/6-31++G** ab initio calculations, which reveal that the preferred mechanism for Cu involves the formation of a T-shaped Cu transition state. [reaction: see text]