136710-93-5Relevant articles and documents
Metal-metal electronic coupling in syn and anti stereoisomers of mixed-valent (FeCp)2-, (RhL2)2-, and (FeCp)(RhL2)-as-indacenediide ions
Santi, Saverio,Orian, Laura,Durante, Christian,Bencze, Eva Zsuzsanna,Bisello, Annalisa,Donoli, Alessandro,Ceccon, Alberto,Benetollo, Franco,Crociani, Laura
, p. 7933 - 7947 (2007)
The extent of metal-metal electronic coupling was quantified for a series of syn and anti stereoisomers of (FeCp)2-, (RhL2) 2- and (FeCp)(RhL2)-(L2 = 1,5-cyclooctadiene (cod), L = CO) as-indacenediide
Two distinct allosteric active sites regulate guest binding within a Fe8Mo1216+ cubic receptor
Ramsay, William J.,Nitschke, Jonathan R.
, p. 7038 - 7043 (2014)
The binding of phosphine ligands to molybdenum sites on the faces of a supramolecular cube served to inhibit allosterically the encapsulation of a neutral or anionic guest. The edges of the cube also provided a distinct second allosteric site, where the binding of tetraphenylborate also allosterically inhibited anion binding in the cubes cavity. The two allosteric sites were shown to regulate the binding of an anionic guest either independently or in concert. The use of a tertiary amine as an allosteric effector also enabled a phosphine guest to be ejected from the cubes cavity into solution, to generate phosphine complexes with other metal ions.
The Arene-Stabilized η5-Pentamethylcyclopentadienyl Arsenic Dication [(η5-Cp*)As(toluene)]2+
Zhou, Jiliang,Liu, Liu Leo,Cao, Levy L.,Stephan, Douglas W.
, p. 5407 - 5412 (2019)
Double chloride abstraction of Cp*AsCl2 gives the dicationic arsenic species [(η5-Cp*)As(tol)][B(C6F5)4]2 (2) (tol=toluene). This species is shown to exhibit Lewis super acidity by the Gutmann–Beckett test and by fluoride abstraction from [NBu4][SbF6]. Species 2 participates in the FLP activation of THF affording [(η2-Cp*)AsO(CH2)4(THF)][B(C6F5)4]2 (5). The reaction of 2 with PMe3 or dppe generates [(Me3P)2As][B(C6F5)4] (6) and [(σ-Cp*)PMe3][B(C6F5)4] (7), or [(dppe)As][B(C6F5)4] (8) and [(dppe)(σ-Cp*)2][B(C6F5)4]2 (9), respectively, through a facile cleavage of C?As bonds, thus showcasing unusual reactivity of this unique As-containing compound.
Synthetic, spectroscopic, structural, and electrochemical investigations of ferricenium derivatives with weakly coordinating anions: ion pairing, substituent, and solvent effects
Carrasco, Maria C.,Hematian, Shabnam,Khan, Firoz Shah Tuglak,Pourhadi, Hadi,Waldbusser, Amy L.
, p. 7433 - 7455 (2021/06/11)
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.
Formation of unexpected silicon- and disiloxane-bridged multiferrocenyl derivatives bearing Si-O-CHCH2 and Si-(CH2)2C(CH3)3 substituents via cleavage of tetrahydrofuran and trapping of its ring fragments
Bru?a, Sonia,González-Vadillo, Ana M.,Ferrández, Marta,Perles, Josefina,Montero-Campillo, M. Merced,Mó, Otilia,Cuadrado, Isabel
, p. 11584 - 11597 (2017/09/18)
The formation of a family of silicon- and siloxane-bridged multiferrocenyl derivatives carrying different functional groups attached to silicon, including Fc2(CH3)3C(CH2)2SiCHCH2 (5), Fc2(CH2CH-O)SiCHCH2 (6), Fc2(OH)SiCHCH2 (7), Fc2(CH2CH-O)Si-O-Si(O-CHCH2)Fc2 (8) and Fc2(CH2CH-O)Si-O-SiFc3 (9) is described. Silyl vinyl ether molecules 6, 8 and 9 and the heteroleptic vinylsilane 5 resulted from the competing metathesis reaction of lithioferrocene (FcLi), CH2CH-OLi or (CH3)3C(CH2)2Li with the corresponding multifunctional chlorosilane, Cl3SiCHCH2 or Cl3Si-O-SiCl3. The last two organolithium species have been likely formed in situ by fragmentation of the tetrahydrofuran solvent. Diferrocenylvinyloxyvinylsilane 6 is noteworthy since it represents a rare example of a redox-active silyl mononomer in which two different CC polymerisable groups are directly connected to silicon. The molecular structures of the silicon-containing multiferrocenyl species 5, 6, 8 and 9 have been investigated by single-crystal X-ray diffraction studies, demonstrating the capture and storage processes of two ring fragments resulting from the cleavage of cyclic THF in redox-active and stable crystalline organometallic compounds. From electrochemical studies we found that by changing the anion of the supporting electrolyte from [PF6]- to [B(C6F5)4]-, the redox behaviour of tetrametallic disiloxane 8 can be switched from a poorly resolved multistep redox process to four consecutive well-separated one-electron oxidations, corresponding to the sequential oxidation of the four ferrocenyl moieties.
