Chloromercuri-ferrocenes

Ferrocene, like thiophene, furan, and other so-called superaromatic systems, reacts readily with mercuric acetate to form mercurated derivatives. Nes-meyanov and coworkers first reported that ferrocene could be mercurated under relatively mild conditions in either ethyl ether-alcohol or benzene-alcohol solution (63). The acetoxymercuriferrocenes formed in this manner are usually treated with an alcoholic solution of an alkali metal halide. The resulting products, chloro-mercuriferrocene (XXVII) and l,l -di(chloromercuri)ferrocene (XXVIII), can be conveniently separated by extraction with n-butyl alcohol. 

Reaction of l,l -di(chloromercuri) ferrocene with sodium iodide or sodium thiosulfate might be expected to lead to higher homologs of XXIX in which ferrocene units are bridged by atoms of mercury. Reactions of this type have produced apparently polymeric materials with structures such as XXX, although the very limited solubility of the products has thus far precluded reliable molecular weight measurements (80). 

Venkatasubbaiah, K., Bats, J. W., Rheingold, A. L., Jakle, F., Rational synthesis and complexation behavior of the bidentate lewis acid l,2-bis(chloromercury)ferrocene. Organometallics 2005, 24, 6043-6050. 

Polyferrocenylenes of previous investigations using copper-, cobalt- or palladium-assisted reactions of l,l -dilithioferrocene or l,r-bis(chloromercuri)ferrocene possessed distinctly stronger paramagnetism and/or were found to contain [0,0]-ferro-cenophane (bisfulvalenediiron) (3 in (Eq. 3)) in various proportions resulting from internal cyclization erf the dinuclear intermediate6). 

Other Carbon-Heteroatom Bonds. Carbon-mercury bonds are readily formed by treating the metalated species with mercuric chloride (Reaction 21) (27). The resulting chloromercury derivative in one case is a useful intermediate in the preparation of 2-iododimethylaminomethyl-ferrocene (27). 

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