Ruthenocenophanes

Abstract

The new dinuclear [1 .l] (5b) was also prepared and studied to gether with the corresponding [n]ferrocenophanes, 10a and 3a-5a. l,l'-Dilithioruthenocene was found to be a versatile starting material for the synthesis of silicon-substituted ruthenocene derivates such as Ru(C5H4-R)2 (R = SiMe3 (6b), Si2Me5 (7b)) and [n]ruthenocenophanes (3b-5b). A complete set o f 1H, 13C and 2 ,Si NMR data is presented, and the available structural data are discussed with respect to the tilt angle a of the cyclopentadienyl ring ligands which is larger in the more strained [2 ]ruthenocenophanes than in the corresponding [2 ]ferrocenophanes.

Isolation of [1]Ruthenocenophanes: Synthesis of Polyruthenocenylstannanes by Ring‐Opening Polymerization

“…This increasing separation has been attributed to an increased tilt angle α in several other cases, but in this study we could not confirm this trend. On the contrary, we found that in some cases Δ δ Cp decreases with increasing α: The [2]ruthenocenophane 3 (M=Ru, α =29.6(5)°) shows a separation of 0.38 ppm for the hydrogen atoms of the Cp ring,12 whereas for the analogous [2]ferrocenophane 3 (M=Fe, α =21.6(5)°)17 this value increases to δ =0.88 ppm 12. The same can be observed for 5 ( 5 : Δ δ Cp =0.34 ppm; 1 (ER n =ZrCp${{\prime \hfill \atop 2\hfill}}$ ): Δ δ Cp =0.37 ppm).…”

“…Attempts to synthesize silicon‐bridged [1]ruthenocenophanes by reaction of the N , N , N ′, N ′‐tetramethylethylenediamine (TMEDA) adduct of dilithiated ruthenocene Ru(C 5 H 4 Li) 2 ⋅TMEDA ( 4 ) with Cl 2 SiMe 2 have been reported to result in the formation of dimeric and oligomeric species 11. 12 Introduction of larger elements such as zirconium or tin as the bridging atoms might be expected to lead to less‐strained and therefore more‐stable [1]ruthenocenophanes. We attempted to prepare the zirconium‐bridged [1]ruthenocenophane by the reaction of 4 with [Cl 2 ZrCp${{\prime \hfill \atop 2\hfill}}$ ] (Cp′=C 5 H 4 t Bu) in Et 2 O at low temperature.…”

Silicon-bridged bis(cyclohexadienyl) iron complexes: the first structurally characterised [14]ferrocenophaneElectronic supplementary information (ESI) available: experimental details and NMR spectroscopic data. See http://www.rsc.org/suppdata/cc/b1/b107874g/

“…Conversely however, the average value of b, the angle between each plane and the bridging atom-bridgehead bond, is slightly greater for [Me 2 Si(DMCh) 2 ]Fe (40.0°) than [Me 2 Si(C 5 H 4 ) 2 ]Fe (37.0°). This deviation from planarity of the sp 2 bridgehead atom of 1 is also reflected in its 13 C NMR resonance, which is found at d 47.4, an upfield shift relative to unbridged compounds. For comparison, the corresponding value for (DMCh) 2 Fe is d 77.9.…”

“…The formation of 2 allows significant relief of the strain observed in the ansa-bridged species 1, as demonstrated by an angle a of 5.4°, and an average value of b of 6.5°. The silicon bridged cyclopentadienyl [1 2 ]ferrocenophane, {[Me 2 -Si(C 5 H 4 ) 2 ]Fe} 2 , which was reported simultaneously by three groups, [11][12][13] has a similar ring tilt [a = 4.9(3)°]. 12 In both cases, the ring tilt is opposite to that of the monomeric species; the greatest inter-ring separation is observed at the silicon-bridged end of the ring.…”

Cyclic and Linear Polyferrocenes with Silicon and Tin as Alternating Bridges

“…Since the synthesis of the first [1.1]FCPs in 1956,7 this family of compounds has grown significantly with the incorporation of B,10 Al,11 Ga,11b, 12 In,11b, 13 Si,14 Sn,15 Pb,16 P,17 As,18 S,19 Zn,20 and Hg21 atoms as heteroatom bridges. In addition to these [1.1]FCPs, other [1.1]metallacyclophanes have been synthesized, such as [1.1]ruthenocenophanes,14a, 22 [1.1]chromarenophanes,23 [1.1]molybdarenophanes,23 and mixed [1.1]metallacyclophanes22 that contained Fe/Ru or Fe/Co metal combinations. In contrast to [1]metallacyclophanes, their formal dimers lack ring strain and no report of a successful ROP of [1.1]metallacyclophanes has been published to date.…”