Cyclooctadiene tricarbonylruthenium

Described here is the preparation of (1,5-cyclooctadiene)-tricarbonylruthenium and its use in the synthesis of tricarbony%-diene)ruthenium complexes. 

The complex functions as the most suitable source of the tricarbonylruth-enium unit in syntheses of tiicarbonyl(i -diene)ruthenium complexes. Derivatives of 1,3-cyclohexadiene, 1,3-cycloheptadiene, cycloheptatriene, cycloocta-tetraene, 2,4,6-cycloheptatrien-l-one, bicyclo[3.2.1]octa-2,6-diene, bicyclo-[3.2.1]octa-2,4-diene, and butadiene have been prepared by displacement of 1,5-cyclooctadiene. 

Although alternative procedures exist for the preparation of some of these compounds, the ligand-displacement method possesses two distinct advantages (1) the absence of side reactions leads to high yields and facilitates the purifications, and (2) the mild conditions required for the reaction to go to completion (refluxing benzene, 30 min) avoid extensive decomposition of the complex formed this makes the method invaluable where the complexes are very unstable. 

DIHYDRIDOBIS(SOLVENT)BIS(TRIPHENYL-PHOSPHINE)IRIDIUM(III) TETRAFLUOROBORATES 

Submitted by ROBERT H. CRABTREE, MICHELLE F. MELLEA, aud JEAN M. MIHELCIC  

In contrast to the very large number of tricarbonyl(i -diene)iron complexes described in the literature,the corresponding ruthenium compounds have received very little attention. This may reflect the well-documented tendency of ruthenium to form metal-metal bonds as opposed to iron. In particular, while the metal-metal bonds in Fe3(CO)i2 are easily broken, Ru3(CO)i2 undergoes a variety of reactions in which the RU3 cluster is retained. 

I Koch-Light Laboratories, CoInbrook, Bucks., United Kingdom. 

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