OLIGODIENYL COMPOUNDS OF D-TRANSITION AND F-TRANSITION METALS - SYNTHESIS AND STABILITY

The results of investigations performed in the Laboratory of Organometallic Catalysis of the A. V. Topchiev Institute of Petrochemical Synthesis of the RAS are reviewed. The oligodienyl compounds of a series of transition metals, R(n)(ol)M and R(n)(of)MX(m) (R(ol) = R'(diene)(3-10), where R' is an alkyl, allyl, alkenyl, or H; (diene)(3-10) is an oligodienyl group with 3-10 monomeric diene units; M = Ti3+ Cr2+, Mn2+, Co2+, Ni2+, Nd3+, Pr3+, Sm3+, and Gd3+; X is a halogen or an electronegative group), have been synthesized for the first time and some of their properties have been studied. The stability of oligodienyl compounds is much higher than that of the corresponding pi-alkenyl derivatives. The IR spectra of the compounds synthesized allowed us to conclude that their stability and some peculiarities of the reactions of these compounds can be explained by pi-coordination of the isolated double bond of the oligodienyl chain to the transition metal.