STUDIES ON REACTIONS OF FERROCENYL-PHENYLACETYLENE AND DIFERROCENYL-ACETYLENE WITH (ETA-5-CYCLOPENTADIENYL)DICARBONYLCOBALT, AND AN X-RAY CRYSTALLOGRAPHIC DETERMINATION OF ONE OF PRODUCTS - (ETA-5-CYCLOPENTADIENYL)(ETA-4-1,3-DIFFERROCENYL-2,4-DIPHENYLCYCLOBUTADIENE)COBAL
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
The reaction of (5-C5H5)Co(CO)2 and diferrocenylacetylene has been shown to produce the mixed sandwich complex (5-cyclopentadienyl)(4-tetraferrocenylcyclobutadiene)cobalt in 83% yield. A similar reaction between (5-C5H5)Co(CO)2 and ferrocenylphenylacetylene produces two structural isomers, (5-cyclopentadienyl)(4-1,2-diferrocenyl-3,4-diphenylcyclobutadiene)cobalt and (5-cyclopentadienyl)(4-1,3-diferrocenyl-2,4-diphenylcyclobutadiene)cobalt, in 78% combined yield. The structures of these two products have been inferred from proton NMR and mass spectral studies, and unequivocally established by means of a single crystal X-ray diffraction investigation of the latter isomer. (5-cyclopentadienyl)(4-1,3-diferrocenyl-2,4-diphenylcyclobutadiene) cobalt, c41H33CoFe2, is monoclinic, P21/c with a = 10.551(3), b = 16.345(2), c = 19.796(3) and B = 93.19. However, the unit cell was found to contain 2 hexane molecules in addition to 4 parent molecules to yield a calculated density of 1.441 g/cm-3. The measured density was 1.44(2) g/cm-3. Intensity data were gathered by the 8-28 scan method with an automated 4-circle diffractometer (CAD-4) yielding 7315 reflections (10,450 scanned) greater than 3. Refinement by full matrix least squares led to a final R of 0.039. The cyclobutadiene ring is square with average bond length of 1.462(5) . However, the ring is not quite planar, one of the carbons being 0.035 out of the plane formed by the other three. Other features of the structure are regular with the ferrocene C5 rings being in the eclipsed conformation. 1978.
