“…50% 1 through reduction of the mixture of 1 + and 2 2+ . Re-electrolysis at E appl = −0.65 V, involving also the reduction of the secondary product, increased the regeneration of ruthenocene to 84% and produced another small wave with E 1/2 = 0.29 V. Reduction of the secondary product, which on the basis of previous literature is likely to be a Ru(IV) species, is therefore seen to mainly regenerate ruthenocene. 2 Cyclic voltammograms to three different switching potentials after anodic oxidation of 5 mM ruthenocene in CH 2 Cl 2 /0.05 M [NBu 4 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ] at 243 K, 1 mm glassy carbon electrode, 0.1 V s -1 . 3 Linear scan voltammograms obtained during electrolysis experiments on 5 mM ruthenocene in CH 2 Cl 2 /0.05 M [NBu 4 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ] at 243 K, 1 mm glassy carbon electrode, 3 mV s -1 scan rate: () (a) initial solution; (−·−·) (b) after anodic electrolysis at E appl = 0.8 V; (- - -) (c) after cathodic re-electrolysis at E appl = −0.12 V; (○) (d) after final cathodic re-electrolysis at E appl = −0.65 V.…”
The electrochemical oxidation of ruthenocene (1) in CH(2)Cl(2)/[NBu(4)]A, where A = [B(C(6)F(5))(4)](-) or [B(C(6)H(3)(CF(3))(2))(4)](-), gives the dimeric dication [(RuCp(2))(2)](2+), 2(2+), in equilibrium with the 17-electron ruthenocenium ion 1(+). At room temperature the rapid equilibrium accounts for the quasi-Nernstian cyclic voltammetry (CV) behavior (E(1/2) = 0.41 V vs FeCp(2), A = [B(C(6)F(5))(4)](-)). Direct electrochemical evidence for 2(2+) is seen by CV and by bulk electrolysis at 243 K. The bis(ruthenocenium) dication undergoes a highly irreversible two-electron cathodic reaction at E(pc) ca. 0 V. Anodic electrolysis of 1 at 243 K using [B(C(6)H(3)(CF(3))(2))(4)](-) as the supporting electrolyte, followed by cathodic electrolysis of 2(2+), regenerates half of the original 1. Precipitation of 2(2+) occurs when the supporting electrolyte is [B(C(6)F(5))(4)](-), allowing facile isolation of [(RuCp(2))(2)][B(C(6)F(5))(4)](2). A second, unidentified, anodic product also reduces to give back ruthenocene. Digital simulations of the CV curves of 1 at 243 K give a dimerization equilibrium constant of 9 x 10(4) M(-1) for K(eq) = [(RuCp(2))(2)(2+)]/2 [RuCp(2)](+) in CH(2)Cl(2)/0.1 M [NBu(4)][B(C(6)F(5))(4)].
“…50% 1 through reduction of the mixture of 1 + and 2 2+ . Re-electrolysis at E appl = −0.65 V, involving also the reduction of the secondary product, increased the regeneration of ruthenocene to 84% and produced another small wave with E 1/2 = 0.29 V. Reduction of the secondary product, which on the basis of previous literature is likely to be a Ru(IV) species, is therefore seen to mainly regenerate ruthenocene. 2 Cyclic voltammograms to three different switching potentials after anodic oxidation of 5 mM ruthenocene in CH 2 Cl 2 /0.05 M [NBu 4 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ] at 243 K, 1 mm glassy carbon electrode, 0.1 V s -1 . 3 Linear scan voltammograms obtained during electrolysis experiments on 5 mM ruthenocene in CH 2 Cl 2 /0.05 M [NBu 4 ][B(C 6 H 3 (CF 3 ) 2 ) 4 ] at 243 K, 1 mm glassy carbon electrode, 3 mV s -1 scan rate: () (a) initial solution; (−·−·) (b) after anodic electrolysis at E appl = 0.8 V; (- - -) (c) after cathodic re-electrolysis at E appl = −0.12 V; (○) (d) after final cathodic re-electrolysis at E appl = −0.65 V.…”
The electrochemical oxidation of ruthenocene (1) in CH(2)Cl(2)/[NBu(4)]A, where A = [B(C(6)F(5))(4)](-) or [B(C(6)H(3)(CF(3))(2))(4)](-), gives the dimeric dication [(RuCp(2))(2)](2+), 2(2+), in equilibrium with the 17-electron ruthenocenium ion 1(+). At room temperature the rapid equilibrium accounts for the quasi-Nernstian cyclic voltammetry (CV) behavior (E(1/2) = 0.41 V vs FeCp(2), A = [B(C(6)F(5))(4)](-)). Direct electrochemical evidence for 2(2+) is seen by CV and by bulk electrolysis at 243 K. The bis(ruthenocenium) dication undergoes a highly irreversible two-electron cathodic reaction at E(pc) ca. 0 V. Anodic electrolysis of 1 at 243 K using [B(C(6)H(3)(CF(3))(2))(4)](-) as the supporting electrolyte, followed by cathodic electrolysis of 2(2+), regenerates half of the original 1. Precipitation of 2(2+) occurs when the supporting electrolyte is [B(C(6)F(5))(4)](-), allowing facile isolation of [(RuCp(2))(2)][B(C(6)F(5))(4)](2). A second, unidentified, anodic product also reduces to give back ruthenocene. Digital simulations of the CV curves of 1 at 243 K give a dimerization equilibrium constant of 9 x 10(4) M(-1) for K(eq) = [(RuCp(2))(2)(2+)]/2 [RuCp(2)](+) in CH(2)Cl(2)/0.1 M [NBu(4)][B(C(6)F(5))(4)].
“…However, the corresponding MMCT absorption appears at 300 nm while the lower-energy LF states are not affected. This situation should also apply to pmo since osmocene is oxidized at even higher potentials than ferrocene [15]. Accordingly, the (Os II ?…”
“…It is well known that they form clusters containing multicentered bonds not only in the solid state and in solution but also in the gas phase because of their electron-deficient nature. The usual number of alkyllithium (LiR) units forming the clusters is 2, 4, or 6; however in certain cases larger or odd-membered aggregates have also been observed. − …”
The electronic structure of some alkyllithium clusters has been investigated by He(I) photoelectron spectroscopy. Two distinct types of spectra have been observed. This is explained by the different degree of association of the compounds in the gas phase, as determined by the steric demand of the alkyl substituent. From the analysis of the spectra it can be concluded that isopropyl-(i-PrLi), sec-butyl-(s-BuLi), and tert-butyllithium (t-BuLi) form only tetramers, while ethyl-(EtLi), n-propyl-(n-PrLi), n-butyl-(n-BuLi), and isobutyllithium (i-BuLi) are mixtures of tetrameric and hexameric clusters in the gas phase. This observation is in accord with former mass spectrometric investigations [Plavs ˇic ´, D.; Srzic´,
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