THE THERMALLY-INDUCED PROTOTROPIC ISOMERIZATION OF ETA-4-1,3-DIALKENES, ETA-4-1,4-DIALKENES, ETA-4-1,5-DIALKENES COMPLEXED TO (ETA-5-CYCLOPENTADIENYL)COBALT

This study reports a series of facile, thermally-induced, prototropic isomerizations of eta4-1,4- and eta4-1,5-dienes of (eta5-cyclopentadie nyl)cobalt to their corresponding eta4-1,3-complexes. The data indicat e the E-isomers to be thermodynamically favored over the Z-isomers. Fu rthermore, in the case of eta4-hexadiene complexes, the eta4-2,4-EE-is omer is observed to be thermodynamically preferred relative to either the eta4-2,4-E,Z- or eta4-1,3-E-isomers.