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

The results of investigations performed in the Laboratory of Organomet allic Catalysis of the A. V. Topchiev Institute of Petrochemical Synth esis 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)(3-1 0), where R' is an alkyl, allyl, alkenyl, or H; (diene)(3-10) is an ol igodienyl group with 3-10 monomeric diene units; M = Ti3+ Cr2+, Mn2+, Co2+, Ni2+, Nd3+, Pr3+, Sm3+, and Gd3+; X is a halogen or an electrone gative group), have been synthesized for the first time and some of th eir properties have been studied. The stability of oligodienyl compoun ds is much higher than that of the corresponding pi-alkenyl derivative s. 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 b ond of the oligodienyl chain to the transition metal.