Conjugated diene complexes crystal structure

The first complex of a conjugated diene was reported in 1930 by Reihlen and coworkers. Reaction of butadiene with FefCOjs gave a yellow-brown oil with the molecular fonnula (CaHejFefCO). The elucidation of the structure of fenocene eventually lead Hallam and Pauson- to propose a jr-complex (1) for (C4H6)Fe(CO)3 and this was eventually confirmed by crystal structure analysis at low temperature. Since that time interest in... 

The rational synthesis of anionic, neutral, and cationic dinuclear palladium complexes containing bridging conjugated dienes is shown in Scheme 32 for butadiene, and consists of the formal redox condensation of Pd(0) and Pd(ii) complexes in the presence of the conjugated diene to give Pd(l) dimers. In addition, some complexes with isoprene and with 1,3-cyclohexadiene were made. The isoprene complexes consisted of the expected pair of regioisomers in the case of the less symmetric neutral molecules. The crystal structures of one neutral complex... 

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