1,5-Cyclooctadienes 4-Cyclooctatetraene metal complexes

Cyclooctatetraene also forms interesting complexes with cobalt, rhodium, nickel, and other transition metals, but these will not be elaborated on here. It should also be mentioned that other eight-mem-bered ring systems, such as 1,5-cyclooctadiene, 1,3,5- and 1,3,6-cyclo-octatrienes, etc., form a variety of metal, t complexes. The most recent survey of cyclooctatetraene and related metal, t complexes is the review by Fischer and Werner (100) as well as earlier reviews by these authors (99) f and Bennett (11). 

It is also not clear why the diolefin 1,5-cyclooctadiene forms a weaker bond to silver than cyclooctene. The effects of strain differences within the olefins and/or within the complexes is not apparent30, but in any case suggests, as noted by the original authors, a negligible interaction between the metal and the second double bond. However, the cyclooctatetraene complex is asserted to be polymeric in solution and so currently precludes obtaining useful information derived from these complexation studies of this species. 

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