372195-07-8

Upstream product

• 1271-55-2 acetylferrocene 
• 848737-65-5 tetrakis(acetonitrile)silver(I) tetrakis(pentafluorophenyl)borate 
• 155543-02-5 lithium tetrakis(pentafluorophenyl)borate/ethyl ether complex 

Relevant academic research and scientific papers

An efficient method to separate Sc3N@C80 I h and D5h isomers and Sc3N@C78 by selective oxidation with acetylferrocenium [Fe(COCH3C 5H4)Cp]+

Based on the different oxidation potentials of endohedral fullerenes Sc3N@C80 Ih and D5h and Sc 3N@C78, an efficient and useful method that avoids HPLC has been developed for their separation. Selective chemical oxidation of the Sc3N@D5h-C80 isomer and Sc3N@C 78 by using an acetylferrocenium salt [Fe(COCH3C 5H4)Cp]+ followed by column chromatographic separation and reduction with CH3SNa resulted in the isolation of pure Sc3N@Ih-C80, Sc3N@C 78, and a mixture of Sc3N@D5h-C80 and Sc3N@C68. Endohedral metallofullerenes: Sc 3N@C80 Ih and D5h isomers and Sc3N@C78 were selectively separated by using a chemical oxidation and reduction method based on their different oxidation potentials (see figure). Copyright

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

A facile and effective strategy for the preparation of a series of ferricenium complexes bearing either electron-donating or electron-withdrawing substituents with weakly coordinating anions such as [B(C6F5)4]?or SbF6?is reported. These systems were thoroughly investigated for their ground state electronic structures in both solution and solid states using infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies as well as single crystal X-ray crystallography and electrochemical measurements. The X-ray structures of the six electron-deficient ferricenium derivatives are of particular interest as only a handful (～5) of such derivatives have been structurally characterized to date. Comparison of the structural data for both neutral and oxidized derivatives reveals that the nature of the substituents on the cyclopentadienyl (Cp) ligands displays a more significant impact on the metal-ligand separations (Fe?Ct) in the oxidized species than in their neutral analogs. Our1H-NMR measurements corroborate that in the neutral ferrocene derivatives, electron-donating ring substitutions lead to a greater shielding of the ring protons while electron-withdrawing groupsviainduction deshield the nearby ring protons. However, the data for the paramagnetic ferricenium derivatives reveals that this substitutional behavior is more complex and fundamentally reversed, which is further supported by our structural studies. We ascribe this reversal of behavior in the ferricenium derivatives to theδback-donation from the iron atom into the Cp rings which can lead to the overall shielding of the ring protons. Interestingly, our NMR results for the electron-deficient ferricenium derivatives in solution also indicate a direct correlation between the solvent dielectric constant and the energy barrier for rotation around the metal-ligand bond in these systems, whereas such a correlation is absent or not significant in the case of the electron-rich ferricenium species or the corresponding neutral ferrocene analogs. In this work, we also present the electrochemical behavior of the corresponding ferricenium/ferrocene redox couples including potential values (E1/2), peak-to-peak separation (ΔE1/2), and diffusion coefficients (D) of the redox active species in order to provide a concise outline of these data in one place. Our electrochemical studies involved three different solvents and two supporting electrolytes. Notably, our findings point to the significant effect of ion-pairing in lowering the energy necessary for reduction of the ferricenium ion andE1/2in lower-polarity media. This has significant implications in applications of the ferrocene or ferricenium derivatives as redox agents in low-polarity solvents where an accurate determination of redox potential is critical.

Influence of cyclopentadienyl ring-tilt on electron-transfer reactions: Redox-induced reactivity of strained [2] and [3] Ruthenocenophanes

In contrast to ruthenocene [Ru(h5-C5H5)2] and di-methylruthenocene [Ru(h 5-C5H4Me)2] (7), chemical oxidation of highly strained, ring-tilted [2]ruthenocenophane [Ru(η5-C5H4)2(CH2)2] (5) and slightly strained [3]ruthenocenophane [Ru(h5-C5H4)2(CH2)3] (6) with cationic oxidants containing the non-coordinating [B(C6F5)4]- anion was found to afford stable and isolable metal-metal bonded dicationic dimer salts [Ru(h5-C5H4)2(CH2)2]2[B(C6F5)4]2 (8) and [Ru(h5-C5H4)2-(CH2)3]2[B(C6F5)4]2 (17), respectively. Cyclic voltammetry and DFT studies indicated that the oxidation potential, propensity for dimerization, and strength of the resulting Ru-Ru bond is strongly dependent on the degree of tilt present in 5 and 6 and thereby degree of exposure of the Ru center. Cleavage of the Ru-Ru bond in 8 was achieved through reaction with the radical source [(CH3)2NC(S)S-SC(S)N(CH3)2] (thiram), affording unusual dimer [(CH3)2NCS2Ru(η5-C5H4)(η3-C5H4)C2H4]2[B(C6F5)4]2 (9) through a haptotropic η5-η3 ring-slippage followed by an apparent [2 + 2] cyclodimerization of the cyclopentadienyl ligand. Analogs of possible intermediates in the reaction pathway [C6H5ERu(η5-C5H4)2C2H4] [B(C6F5)4] [E = S (15) or Se (16)] were synthesized through reaction of 8 with C6H5E-EC6H5 (E = S or Se).

Synthesis, characterization and chemistry of bis-(pentafluorophenyl)boryl ferrocene

Bis-(pentafluorophenyl)boryl ferrocene, 1, was prepared via borylation of ferrocene with HB(C6F5)2 or via a transmetallation reaction involving FcHgCl and ClB(C6F5)2 in 87-91% yield. The compound is characterized by a deep maroon colour. A significant intramolecular iron-boron interaction is manifested in the solution spectroscopic (Fe → B charge transfer band at ～230 nm, ε = 1.33 × 104) and solid-state crystallographic data (Fe-B = 2.924 A) This interaction has an impact on the Lewis acidity of the boron center which, unlike the related compound B(C6F5)3, does not strongly bind Lewis bases such as acetone, THF, or acetonitrile. However, an adduct between the stronger base PMe3 and 1 forms readily and this complex (2) was fully characterized. The electron withdrawing -B(C6F5)2 group causes 1 to be oxidized at +450 mV relative to ferrocene. Oxidation of 1 with [NO][BF4], AgOSO2CF3, or AgC6F5 leads to the zwitterionic ferrocenium borates 3-F, 3-OTf, and 3-C6F5, respectively. Each of these compounds was characterized spectroscopically and via X-ray crystallography. The properties of these compounds relative to 1 suggest that oxidation of the iron center significantly enhances the Lewis acidity of the boron center. Due to the σ-donating ability of the borate substituents, zwitterions 3 are weaker oxidizing agents than unsubstituted ferrocenium salts.