Further reactions of some bis(vinylidene)diruthenium complexes

Bruce, Michael I.; Ellis, Brian; Skelton, Brian W.; White, Allan H.

doi:10.1016/j.jorganchem.2004.09.084

Cited by 17 publications

(21 citation statements)

References 27 publications

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“…Interestingly, the replacement of ruthenium in 1a with iron in 1b resulted in a slightly negative shift of the first anodic wave (at E 1/2 (1)) and significantly decreased comproportionation constant K c (Table ). It will be shown in the spectro-electrochemical section that the formally Fe(II) centers in the terminal positions of 1b oxidize in a more localized fashion compared to the Ru(II) derivative, 1a , as also encountered in the literature for related compounds. ,,, Accordingly, the two formally Fe(II) centers in 1b communicate poorly through the twisted ethynyl–phenylene–N–phenylene–ethynyl bridge, in line with the small Δ E 1/2 (1–2) and K c values for [ 1b ] + . Consequently, it was hardly possible to record IR and UV–vis–NIR spectra of “pure” [ 1b ] + in the course of the corresponding spectro-electrochemical experiments described in the following section.…”

Section: Resultssupporting

confidence: 75%

Multistep Oxidation of Diethynyl Oligophenylamine-Bridged Diruthenium and Diiron Complexes

et al. 2017

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Homo-dinuclear nonlinear complexes [{M(dppe)Cp*}{μ-(-C≡C)X}] (dppe = 1,2-bis(diphenylphosphino)ethane; Cp* = η-CMe; X = triphenylamine (TPA), M = Ru (1a) and Fe (1b); X = N,N,N',N'-tetraphenylphenylene-1,4-diamine (TPPD), M = Ru (2a)) were prepared and characterized by H,C, and P NMR spectroscopy and single-crystal X-ray diffraction (1a, 2a). Attempts to prepare the diiron analogue of 2a were not successful. Experimental data obtained from cyclic voltammetry, square wave voltammetry, UV-vis-NIR (NIR = near-infrared) spectro-electrochemistry, and very informative IR spectro-electrochemistry in the C≡C stretching region, combined with density functional theory calculations, afford to make an emphasizing assessment of the close association between the metal-ethynyl termini and the oligophenylamine bridge core as well as their respective involvement in sequential one-electron oxidations of these complexes. The anodic behavior of the homo-bimetallic complexes depends strongly both on the metal center and the length of the oligophenylamine bridge core. The poorly separated first two oxidations of diiron complex 1b are localized on the electronically nearly independent Fe termini. In contrast, diruthenium complex 1a exhibits a significantly delocalized character and a marked electronic communication between the ruthenium centers through the diethynyl-TPA bridge. The ruthenium-ethynyl halves in 2a, separated by the doubly extended and more flexible TPPD bridge core, show a lower degree of electronic coupling, resulting in close-lying first two anodic waves and the NIR electronic absorption of [2a] with an indistinctive intervalence charge transfer character. Finally, the third anodic waves in the voltammetric responses of the homo-bimetallic complexes are associated with the concurrent exclusive oxidation of the TPA or TPPD bridge cores.

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Section: Resultssupporting

confidence: 75%

Multistep Oxidation of Diethynyl Oligophenylamine-Bridged Diruthenium and Diiron Complexes

et al. 2017

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“…of [FeCp 2 ]PF 6 at -78°C to yield the bimetallic bis(vinylidene), which is then readily deprotonated to form the bimetallic butadiynediyl complexes [{M(dppX)(L)} 2 (1,4-μ-CϵC-CϵC)] (Scheme 17). [112,[135][136][137][138] Scheme 17. Oxidative coupling and subsequent deprotonation to yield bimetallic μ-1,3-diyne-1,4-diyl complexes.…”

Section: Cp]mentioning

confidence: 99%

“…[136,[145][146][147] Therefore the intermediacy of vinylidenes cannot be excluded in the conversion of alkynyl radical cations into carbonyls. However, these reactions are generally slow and a growing body of evidence points to more direct hydrolysis mechanisms that may occur on faster timescales.…”

Section: Whereas Reaction Of For Example [Ru{c=c(h)-ph}l(pph 3 )Cp]mentioning

confidence: 99%

Ligand Redox Non‐Innocence in Transition‐Metal σ‐Alkynyl and Related Complexes

Schauer

Low

2011

Eur J Inorg Chem

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Transition-metal σ-alkynyl complexes are valuable functional materials that have found application as sructural units in the assembly of polymetallic arrays and large molecular structures, reagents for the transfer, oligomerisation or functionalisation of alkynes, magnetic or optical materials and putative components for use in a future molecular-based electronics platform. Many σ-alkynyl complexes are redoxactive, undergoing facile oxidation (reduction) at moderate potentials to generate radical cations (anions) in which the

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“…Similar dimerizationp henomena have previously been observed for analogousR ua nd other metal complexes. [22] In particular,t he aforementioned divinylidene [{Cp(PPh 3 ) 2 Ru} 2 -(m-C 4 Ph 2 )][PF 6 ] 2 ,i solated by Bruce et al by treatment of Cp(PPh 3 ) 2 RuC 2 Ph with AgC 2 Ph, [23] presents an analogouss tructure to that hypothesized for 2F.…”

Section: Characterizationmentioning

confidence: 95%

“…For analogous metal complexes,e xperimental observations, supported by calculations, have identified C b of the alkynyl moiety as as ite very prone to further reactivity. [21][22][23][24] Thus, one possible explanation for the chemical reaction observed here,r esulting from the oxidationo f2A,c ould be that of aC b -C b radicald imerizationb etween two oxidized [Ru*]-DHA species. Am ore detailed investigation into the oxidative dimerizationp roducts of Cp(PPh 3 [23] In othert rials, oxidations of Cp*(dppe)RuC 2 PhX using AgOTf also resulted in unstable radical cations leadingt om ore complex product mixtures.…”

Section: Characterizationmentioning

confidence: 99%

Multistate Switches: Ruthenium Alkynyl–Dihydroazulene/Vinylheptafulvene Conjugates

Vlasceanu

Andersen

Parker

et al. 2016

Chemistry A European J

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Multimode molecular switches incorporating distinct and independently addressable functional components have potential applications as advanced switches and logic gates for molecular electronics and memory storage devices. Herein, we describe the synthesis and characterization of four switches based on the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermoswitch pair functionalized with the ruthenium-based Cp*(dppe)Ru ([Ru*]) metal complex (dppe=1,2-bis(diphenylphosphino)ethane; Cp*=pentamethylcyclopentadienyl). The [Ru*]-DHA conjugates can potentially exist in six different states accessible by alternation between DHA/VHF, Ru(II) /Ru(III) , and alkynyl/vinylidene, which can be individually stimulated by using light/heat, oxidation/reduction, and acid/base. Access to the full range of states was found to be strongly dependent on the electronic communication between the metal center and the organic photoswitch in these [Ru*]-DHA conjugates. Detailed electrochemical, spectroscopic (UV/Vis, IR, NMR), and X-ray crystallographic studies indeed reveal significant electronic interactions between the two moieties. When in direct conjugation, the ruthenium metal center was found to quench the photochemical ring-opening of DHA, which in one case could be restored by protonation or oxidation, allowing conversion to the VHF state.

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Further reactions of some bis(vinylidene)diruthenium complexes

Cited by 17 publications

References 27 publications

Multistep Oxidation of Diethynyl Oligophenylamine-Bridged Diruthenium and Diiron Complexes

Multistep Oxidation of Diethynyl Oligophenylamine-Bridged Diruthenium and Diiron Complexes

Ligand Redox Non‐Innocence in Transition‐Metal σ‐Alkynyl and Related Complexes

Multistate Switches: Ruthenium Alkynyl–Dihydroazulene/Vinylheptafulvene Conjugates

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