Conformational Properties of Substituted Ferrocenes:  Experimental and Theoretical Studies of the Molecular Structures of 1,1‘-Di-tert-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 C 2h symmetry, electron diffraction and calculations support a mixture of C 2 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.

The molecular structure of [Sn(P2C2But2)] using gas-phase electron diffraction and DFT calculations

“…DFT methods have also been used to investigate the structures of substituted ferrocenes with good results. 47 Recently, photoelectron spectroscopic measurements and/or DFT calculations have given information about the electronic structures of the following phospha-metallocenes [M(g 5…”

Synthetic, spectroscopic, structural, and electrochemical investigations of ferricenium derivatives with weakly coordinating anions: ion pairing, substituent, and solvent effects

“…This is consistent with the overall trend observed in ferrocene derivatives highlighting that the structures with eclipsed conformations reach considerably larger bending angles. 39,43 The difference between structures of Ac2 FcBArF20 and its neutral analog, Ac2 Fc is even more pronounced. The Ac2 Fc + complex crystallizes in the monoclinic space group P21/c, with the Cp rings in staggered arrangements (ϕ = -26.4°) in contrast to the nearly eclipsed conformation observed for Ac2 Fc (ϕ = 139.6°).…”

A general diastereoselective synthesis of highly functionalized ferrocenyl ambiphiles enabled on a large scale by electrochemical purification

“…The presence of the tert-butyl groups hampers a trans-arrangement of the functions (P-Ct-Br ca 180°) in agreement with the predicted conformational properties of substituted ferrocenes. 21 This journal is © The Royal Society of Chemistry We achieved the introduction of boryl functions on compounds 3a-c after Br/Li exchange (Scheme 1), to give 4a-d in excellent yields (81-99%) except for the hindered 4d (35%). We characterized these ambiphiles in the solid state by X-ray diffraction studies (Figure 3) and in solution by NMR (Table 1).…”