SYNTHESIS AND CHARACTERIZATION OF BIMETALLIC COMPLEXES WITH THE BRIDGING ETA-2(SIGMA,SIGMA)-1,3-BUTADIYNE-1,4-DIYL LIGAND

The complex (η5-C5H5)(CO)2FeC≡CC≡CH was prepared by sequential treatment of LiC≡CC≡CSi(CH3)3 with (η5-C5H)(CO)2FeCl and tetrabutylammonium fluoride. The monometallic complexes (η5-C5H5)(CO)-LFeC≡CC≡CH (L = CO, PPh3) were deprotonated with sec-BuLi, and the resulting anions were trapped with (η5-C5H5)M(CO)nCl to form (η5-C5H5)(CO)LFeC≡CC≡CM(CO)n(η5-C5H5) (n = 2, M = Fe, L = CO, PPh3; n = 3, M = Mo, L = CO, PPh3; n = 3, M = W, L = CO, PPh3) in 55‒86% isolated yield. IR data suggest that the buta diynediyl ligand is effective in conveying electronic information between the two metal centers of the bimetallic molecules. © 1990, American Chemical Society. All rights reserved.