Chemical Activation of Zinc

Alloys with Metals. In the beginning of this chapter reference was made to Pebal s [1] advice, in 1861, to activate zinc by etching with sulfuric acid, for its reaction with iodoethane. 

In later periods by far the most widely used method for the activation of zinc was alloying it with copper. In one of the standard textbooks for organometallic chemistry [53] the preparation was described of not less than five different Zn/Cu couples. Furthermore three different Zn/Pb couples were mentioned in the same reference, indicating the large number of problems encountered with this metal. 

Surprisingly Zn/Cu couples were also used for Zn-Barbier reactions when modern techniques of activation were used to have the reaction starting e.g. a 50% Zn/Cu couple had proved its superiority over other types of activated zinc [54] in the following reaction  

In a review of the Simmons-Smith reaction [55] it is stated that the copper plays no other role than activating the zinc surface for reaction, and that in ether 

Another metal, used in alloys with zinc was silver a Zn/Ag couple was successfully used in a modification of the Simmons-Smith reaction [57]. 

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