PHOTOCHEMICAL-SYNTHESIS AND CRYSTAL-STRUCTURE OF 2 POTENTIALLY USEFUL METAL-CARBONYL-COMPLEXES - PENTACARBONYL(ETA-2-CIS-CYCLOOCTENE)-TUNGSTEN(0) AND TETRACARBONYLBIS(ETA-2-CIS-CYCLOOCTENE)TUNGSTEN(0)

W(CO)5(C8H14) and W(CO)4(C8H14)2 were synthesized photochemically from W(CO)6 and cis-cyclooctene with a respective yield of 71% and 18%. The compounds were characterized by NMR, IR and single X-ray crystallography. The IR spectra of the two compounds exhibited characteristic bands for the mono- and bis-substituted metal carbonyl complexes. In W(CO)4(C8H14)2, the cis-cyclooctene ligands are in a trans configuration with the double bonds perpendicular to each other. The two crystal structures were refined to R = 0.040 for W(CO)5(C8H14) and 0.025 for W(CO)4(C8H14)2. Although the tungsten-carbon (of the carbonyl groups) distances are very similar in both structures, the distances between the tungsten atom and the olefinic carbons are shorter in W(CO)4(C8H14)2, 2.36 angstrom, than in W(CO)5(C8H14), 2.51 angstrom.