1,1′-Bis(tert-butyldimethylsilyl)ferrocene

The asymmetric unit of the title compound, [Fe(C11H19Si)2], consists of one half of a ferrocene derivative. The FeII atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclopentadienyl ligands. No significant intermolecular interactions are observed in the crystal structure.

The asymmetric unit of the title compound, [Fe(C 11 H 19 Si) 2 ], consists of one half of a ferrocene derivative. The Fe II atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclopentadienyl ligands. No significant intermolecular interactions are observed in the crystal structure.

Experimental
Crystal data [Fe(C 11  supplementary materials . E69, m46 [doi:10.1107/S1600536812049069] 1,1′-Bis(tert-butyldimethylsilyl)ferrocene Abdolreza Abri, Behzad Soltani, Christopher J. Ziegler, James T. Engle and Reza Kia Comment Ferrocene has attracted the interest of many scientists and research groups worldwide because of its applications in materials science (Hudson et al., 2001;Liu et al., 2000). Ferrocene as a starting material in synthetic organometallic systems and its derivatives in industrial applications have become a great area of interest for many researchers and industrial chemists.
The asymmetric unit of the title compound comprises a half of a ferrocene drivative (Fig. 1). The Fe II atom lies on a twofold rotation axis, giving an eclipsed conformation for the cyclopentadienyl ligands. The bond lengths and angles are within the normal ranges and are comparable to the related structure (Ren et al., 2012).

Experimental
To a stirred solution of ferrocene (5.00 g, 26.88 mmol) in 100 ml of n-hexane, a solution containing 9.2 ml (60 mmol) tetramethylethylenediamine (tmeda) and 35 ml (56 mmol) of a 1.6 M of n-BuLi in 30 ml of n-hexane was added dropwise over 5 min, and mixture was stirred overnight. The orange precipitate of FcLi 2 was collected. A THF solution (20 ml) containing FcLi 2 (0.67 g, 3.5 mmol) was added dropwise to a THF solution (10 ml) of 1.67 ml t-butyldimethylchlorosilane (13.9 mmol) at -30 °C, and were kept for 30 min at -30 °C and then stirred over night at room temperature. The solvent THF was evaporated together with the excess of chlorosilane under vacuum, then, the orange residue dissolved in n-hexane (30 ml) and the solution filtered over Na 2 SO 4 . The solvent n-hexane was removed under vacuum and the product heated up for 1 h in order to sublime the impurities of ferrocene off. The remaining dark-orange oil or solid (0.69 g, 55% yield) was obtained. Single Crystals suitable for X-ray analysis were obtained by slow evaporation from a nhexane solution at room temperature.

Refinement
All hydrogen atoms were positioned geometrically with C-H = 0.95 or 0.98 Å and included in a riding model approximation with U iso (H) = 1.2U eq (C).  The ORTEP plot of the title compound, showing 40% probability displacement ellipsoids and the atomic numbering [symmetry code for suffix A: -x + 2, y, -z + 1/2]. The H atoms were omitted for clarity. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.