 The methodology followed was the same as for simple U(COT)2 but some of the compounds properties were found to be different.The tetraphenylcyclooctatetraene complex was found to be completely air stable by Streitwieser, this high stability is probably due to the hindering effects of the phenyl groups, protecting the U4+ center from an attack by oxygen.All these derivatives are much more soluble in organic solvents such as benzene , they form green solutions that are more air sensitive than the crystalline solids.