SOME REACTIONS OF METAL ATOMS WITH ARENES ILLUSTRATING THE IMPORTANCEOF HALF-SANDWICH MOLECULES, M(ARENE), AS REACTION INTERMEDIATES

Reactions of chromium or molybdenum atoms with mixtures of bromobenzen e and other arenes at -196 degrees C have given several new sandwich c ompounds including [Cr(C6H5Br)(C6F6)] and [Mo(C6H5Br)(C6F6)]. The work has led to the development of a theory for the mechanism of reaction of metal atoms with arenes which focuses on the redox properties of th e coordinatively unsaturated half sandwich intermediate M(arene). The theory is then applied to explain the results of other new and known m etal atom-arene reactions.