Conformational Properties of Substituted Ferrocenes: Experimental and Theoretical Studies of the Molecular Structures of 1,1‘-Di-<i>tert</i>-butylferrocene and Isopropylferrocene

Abstract

The molecular structures of 1,1‘-di-tert-butylferrocene (1) and isopropylferrocene (2) have been examined by solid-state X-ray crystallography, gas-phase electron diffraction, and DFT and molecular mechanics calculations. Whereas the solid-state structure of 1 has crystallographically imposed staggered C2h symmetry, electron diffraction and calculations support a mixture of C2 eclipsed isomers. The eclipsed ring−ring and the ring−isopropyl conformations found for 2 are essentially identical in the solid and gas phase and are supported by calculations. The molecular mechanics analysis may be extended to other alkylferrocene derivatives.