The complex Co4(CO)10(CF3C2CH3)
is formed at room temperature from dodecacarbonyltetracobalt and 1,1,1-trifluorobut-2-yne.
Another monoalkyne complex Co2(CO)6(CF3C2CH3)
has been prepared from octacarbonyldicobalt and 1,1,1-trifluorobut-2-yne at
room temperature. Treatment with triphenylphosphine converts the complex into
Co2(CO)4[P(C6H5)3]2(CF3C2CH3).
At 150�, reaction of Co2(CO)6(CF3C2CH3)
and 1,1,1-trifluorobut-2-yne gives a small amount of a purple complex which is
believed to be Co2(CO)4(CF3C2CH3)3.
Similar reactions involving Co2(CO)4(CF3C2CH3)
and the alkynes hexafluorobut-2-yne and 3,3,3-trifluoropropyne give the
complexes Co2(CO)4(CF3C2CH3)(CF3C2CF3)2
and Co2(CO)4(CF3C2CH3)(CF3C2H)2.
Spectroscopic studies have led to an assignment of the substitution pattern in
these latter complexes. Tris-alkyne complexes were not isolated from similar
reactions between 1,1,1-trifluorobut-2-yne and the complexes Co2(CO)6(CF3C2CF3)
and Co2(CO)6(CF3C2H).
Three isomers of the π-cyclopentadienone-π-cyclopentadienylcobalt
complex, [(CF3C2CH3)2CO]Co(π-C5H5),
were obtained from (π-C6H6)Co(CO)2 and
1,1,1-trifluorobut-2-yne after U.V. irradiation for several days. The isomers
vary in the arrangement of the substituents attached to the cyclopentadienone
ring.
All reactions involving
1,1,1-trifluorobut-2-yne have been compared with similar reactions involving
the related alkynes hexafluorobut-2-yne and but-2-yne.
Reaktive π-Komplexe der elektronenreichen Übergangsmetalle, 11. Mitteilung/ Reactive π-Complexes of the Electron Rich Transition Metal Complexes, Part 11
