1, 2-Diphenylcyclooctatetraene (I) has been prepared by copolymerization of diphenylacetylene with acetylene; o-diphenylbenzene was formed as a by-product. Evidence for the structure of 1, 2-diphenylcyclooctatetraene was obtained by hydrogenation, in which a large amount of cis-and a small amount of trans-1, 2-diphenylcyclooctane were formed. The structure of cis-1, 2-diphenylcyclooctane was confirmed by an independent ...