THE FORMATION AND REACTION CHEMISTRY OF TADIENYL)(ETA(4)-TETRAPHENYLCYCLOBUTADIENE)-COBALT AND TADIENYL)(ETA(4)-TETRAPHENYLCYCLOBUTADIENE)-COBALT

tadienyl)(eta(4)-tetraphenylcyclobutadiene)cobalt, which has been synt hesized from (eta(5)-benzoylcyclopentadienyl)dicarbonylcobalt and 2 eq uivalents of diphenylacetylene, undergoes typical organic reactions, i ncluding reduction with sodium borohydride, reduction with lithium alu minum hydride/aluminum chloride, as well as the Wittig reaction. ntadi enyl)(eta(4)-tetraphenylcyclobutadiene)cobalt has also been prepared f rom a(5)-carbomethoxycyclopentadienyl)dicarbonylcobalt and diphenylace tylene. The ester can be readily converted into the corresponding carb oxylic acid, and sequentially into the acid chloride, amide, and cyano derivatives. The anhydride was prepared from the acid chloride. A Fri edel-Crafts acylation reaction of cyclopentadienyl)(eta(4)-tetraphenyl cyclobutadiene ferrocene and aluminum chloride in refluxing 1,2-dichlo roethane has afforded a heterobimetallic ketone, tadienyl)(eta(4)-tetr aphenylcyclobutadiene)cobalt.