Synthesis, crystal structure of Z-1,2-dimethyl-1,2-bis-(m-ferrocenyl-phenyl)ethene

The binuclear ferrocene derivative, Z-1, 2-dimethyl-1, 2-bis (m-ferrocenylphenyl)e hene (Z-DDFP) has been isolated from the mixture of the coupling reaction of m-ferrocenylacetophenone (m-FAP) by the low-valent titanium salts obtained from zinc/titanium tetrachloride in THF. The single crystal X-ray structure of the complex as benzene solvate has been determined and found to be triclinic with cell constants a=7.748(5), b=10.600(7), c=18.550(4)Å, α=97.565(5)°, β=98.551(8)°, γ=90.318(8)° and V=1494.2ų. The structure was refined by [least-squares method for 5151 independent reflections with I>3σ(I) to a final R=0.0363 and R_w=0.0523. The two cyclopentadienyl rings in each ferrocenyl unit are approximately parallel. The two phenyl rings are significantly twisted by 66.80° from each other in the stable configuration. Both the ferrocenyl units on the same side of the C=C double bond are not co-planar with a mean dihedral angle of 96.28°. The structural analysis shows that the chain linking two central iron atoms is about 18Å, significantly close to those found in some biological models.