Charge-transfer complexes of fullerene C70 and ternary amines in chlorobenzene. Picosecond dynamics of charge recombination

The kinetics of charge recombination in radical ion pairs C₇₀ ^–/Am⁺ (Am isN, N, NN-tetramethyl-p-phenylenediamine,p-methoxy-N,N-dimethylaniline,p-methyl-N,N-di-methylaniline,N,N-diethylaniline,N,N-dimethylaniline, and triphenylamine) in chlorobenzene was studied by the picosecond laser photolysis technique. The radical ion states are the products of excitation of charge-transfer complexes between C₇₀ and amines and are also formed by quenching of the singlet excited state of C₇₀ by the amine. The rate constant of electron transfer in the radical ion pair decreases as the free Gibbs energy (G) of the reaction increases and reflects the Marcus-inverted region of the dependence of the rate constant on G. The C₇₀/Am and C₆₀/Am systems are compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1151–1158, May, 1996.     

Photoinduced electron transfer of fullerenes (C60 and C70) studied by transient absorption measurements in near-IR region

Efficiencies and rates of electron transfer from various electron donors to excited fullerenes (C₆₀ and C₇₀) have been determined by observing the transient absorption bands in the near-IR region, where the anion radicals of fullerenes appear. From the rise of the absorption bands of C₆₀ ⁻⁺ and C₇₀ ⁻⁺ in the near-IR region, electron transfer takes place via the triplet states (^TC₆₀ ^* and ^TC₇₀ ^*) under appropriately low concentrations of electron donors. By analysis of the rise curves C₆₀ ⁻⁺ and C₇₀ ⁻⁺, contribution of the excited singlet states (^SC₆₀ ^* and ^SC₇₀ ^*) in addition to the route of the triplet states (^TC₆₀ ^* and ^TC₇₀ ^*) is confirmed. The quantum yield for electron transfer via the triplet states Φ_ct ^T was evaluated by the ratio of [C₆₀ ⁻⁺]/[^TC₆₀ ^*] (or [C₇₀ ⁻⁺/[^TC₇₀ ^*]). The Φ_ct ^T depends upon the donor-ability, donor concentration, and solvent polarity. The back electron-transfer process, which was evaluated by observing C₆₀ ⁻⁺, also depends upon the solvent polarity.     

Formation of cation–radical anion pairs derived from carboxybenzophenone–tetrabutylammonium salts. Pulse radiolysis studies

Pulse radiolysis of acetonitrile solutions of tetra-n-butyl ammonium salts of 2- and 4-carboxybenzophenones [BP-COO⁻···N⁺(C₄H₉)₄] were performed in order to generate directly the reduced forms of the benzophenone moieties within pre-formed ion pairs. In earlier studies on photochemical electron transfer reactions, ion pairs containing a tetraalkyl ammonium cation and a benzophenone radical anion were formed in an electron transfer to the triplet BP from a quencher consisting of a tetraalkyl ammonium salt of (phenylthio)acetic acid. In the current work, the [BP^•−COO⁻···N⁺(C₄H₉)₄] ion pairs were formed by direct reduction of the salts without the complication of a third moiety, i.e., the (phenylthio)acetic anion. The spectra and kinetic parameters of the radiolytically-reduced salts were compared to the behavior of reduced forms of the 2- and 4-COOH substituted benzophenones. The results from the pulse radiolysis and photochemistry were compared and explained in terms of the different structures of the ion pairs.     

Magnetic properties of fullerene salts containing d- and f-metal cations (Co2+, Ni2+, Fe2+, Mn2+, Eu2+, Cd2+). Specific features of the interaction between C60·? and the metal cations

The interaction between the radical anions C₆₀ ^·− and divalent d- and f-metal (Co, Fe, Ni, Mn, Eu, Cd) cations in DMF and acetonitrile-benzonitrile (AN-BN) mixture was studied. Black solid polycrystalline salts (C₆₀ ^·−)₂{(M²⁺)(DMF) _x } (x = 2.4–4, 1–6) containing the radical anions C₆₀ ^·− and metal(ii) cations solvated by DMF were prepared for the first time and their optical and magnetic properties were studied. The salts containing Co²⁺, Fe²⁺, and Ni²⁺ are characterized by antiferromagnetic interactions between the radical anions C₆₀ ^·−, which result in unusually large broadening of the EPR signal of C₆₀ ^·− upon lowering the temperature (from 5.55–12.6 mT at room temperature to 35–40 mT at 6 K for Co²⁺ and Ni²⁺). The salts containing Mn²⁺ and Eu²⁺ form diamagnetic dimers (C₆₀ ⁻)₂, which causes a jumpwise decrease in the magnetic moment of the complexes and disappearance of the EPR signal of C₆₀ ^·− in the temperature range 210–130 K. A feature of salt 6 is magnetic isolation of the radical anions C₆₀ ^·− due to the presence of diamagnetic cation Cd²⁺. The salts prepared are unstable in air and decompose in o-dichlorobenzene or AN. Reactions of C₆₀ ^·− with metal(ii) cations in AN-BN mixture result in decomposition products of the salts that contain neutral fullerene dimers and metals solvated by BN. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1909–1919, September, 2008.     

Activation of molecular oxygen in trifluoroacetic acid

The interaction of molecular oxygen with aqueous trifluoroacetic acid (TFA) led to an increase in pH. This effect was explained by a decrease in the concentration of the protonated CF₃CO₂H₂⁺ and H₃O⁺ species after oxygen was fed in the reactor. Quantum-chemical calculations show that a radical pair can be formed in an activation-free exothermal reaction involving the radical residue of the acid, the CF₃CO₂H₂⁺...³O₂...CF₃CO₂⁻ peroxide radical, and the acid molecule in the CF₃C₂^·...HOO^· collision complex. It was assumed that the activation of molecular oxygen in aqueous TFA solutions, providing the activity of the system in oxidations of various organic and inorganic substrates, is related to the formation of peroxide radicals in them.     

Photoinduced electron transfer reactions in the 10-methylacridinium cation–benzyltrimethylsilane system: steady-state and flash photolysis studies

The mechanism of the photoinduced reaction of the lowest excited singlet state of the 10-methylacridinium (AcrMe⁺) cation with benzyltrimethylsilane (BTMSi) in acetonitrile has been investigated by means of steady-state and time-resolved methods. A variety of stable products was found after irradiation (365 nm) of the reaction mixture under aerobic and oxygen-free conditions. The stable products were identified and analyzed using UV–Vis spectrophotometry, high performance liquid chromatography (HPLC), and mass spectrometry (MS). Based on Stern–Volmer plots of the AcrMe⁺ fluorescence quenching by BTMSi (using fluorescence intensity and lifetime measurements), the rate constants were determined to be k _q = 1.24 (± 0.02) × 10¹⁰ M⁻¹ s⁻¹ and k _q = 1.23 (± 0.02) × 10¹⁰ M⁻¹ s⁻¹, i.e., close to the diffusion-controlled limit in acetonitrile, indicating the dynamic quenching mechanism. The quenching process was shown to occur via an electron-transfer reaction leading to the formation of acridinyl radicals (AcrMe^•) and C₆H₅CH₂Si(CH₃)₃ ^•+ radical cations. Based on stationary and flash photolysis experiments, a detailed mechanism of the secondary reactions is proposed and discussed. The AcrMe^• radical was shown to decay by two processes. The fast decay, observed on the nanosecond timescale, was attributed to the back-electron transfer occurring within the initial radical ion pair. The slow decay on the microsecond timescale was explained by recombination reactions of radicals which escaped from the radical pair, including benzyl radicals formed via C–Si bond cleavage in the C₆H₅CH₂Si(CH₃)₃ ^•+ radical cation.     

Studies of the reaction of the hydroxyl radical with the oxalate ion in an acidic aqueous solution by pulse radiolysis

The reaction of the · OH radical with the oxalate ion in an acidic aqueous solution was studied by pulse radiolysis. The rate constant for the reaction of formation of the radical HOOC-COO·(λ_max = 250 nm, ɛ = 1800 L mol⁻¹ cm⁻¹) is (5.0±0.5)·107 L mol⁻¹ s⁻¹. In the reaction with the hydrogen ion (k = 1.1·10⁷ L mol⁻¹ s⁻¹), the radical HOOC-COO· is transformed into a nonidentified radical designated arbitrarily as H⁺(HOOC-COO)· (λ_max = 260 nm, ɛ = 4000 L mol⁻¹ cm⁻¹). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1165–1167, June, 2008.     

Fullerene complexes with bis(η6-hexamethylbenzene)chromium, hexamethylbenzene, and hexaethylbenzene

The [60]fulleride of bis(η-hexamethylbenzene)chromium(I) [(η⁶-C₆Me₆)₂Cr]^⋅+[C₆₀]^⋅−, and the complexes C₆₀·C₆Me₆ and C₆₀·C₆Et₆ were synthesized. Thermal decomposition of [(η⁶-C₆Me₆)₂Cr]^⋅+[C₆₀]^⋅− was studied. The molecular structures of C₆₀·C₆Me₆ and C₆₀·C₆Et₆ were determined. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 220—224, February, 2006.     

Synthesis and properties of bis(biphenyl)chromium(<Emphasis Type="SmallCaps">i</Emphasis>) 1,4-di(2-cyanoisopropyl)-1,4-dihydrofulleride and 1-(2-cyanoisopropyl)-1,2-dihydrofullerene

Radical-ion salts bis(biphenyl)chromium(i) 1,4-di(2-cyanoisopropyl)-1,4-dihydrofulleride [(Ph₂)₂Cr]^+·[1,4-(CMe₂CN)₂C₆₀]^−· and bis(biphenyl)chromium(i) 1-(2-cyanoisopropyl)-1,2-dihydrofulleride [(Ph₂)₂Cr]^+·[1,2-(CMe₂CN)(H)C₆₀]^−·, the salt bis(biphenyl)chromium(i) (2-cyanoisopropyl)fulleride [(Ph₂)₂Cr]^+·[(CMe₂CN)C₆₀]⁻, and neutral 1-(2-cyanoisopropyl)-1,2-dihydrofullerene 1,2-(CMe₂CN)(H)C₆₀ have been synthesized for the first time. The compounds [(Ph₂)₂Cr]^+·[1,4-(CMe₂CN)₂C₆₀]^−· and [(Ph₂)₂Cr]^+·[1,2-(CMe₂CN)(H)C₆₀]^−· decompose in THF to form [(Ph₂)₂Cr]^+·[(CMe₂CN)C₆₀]⁻, whose protonation affords 1,2-(CMe₂CN)(H)C₆₀. 1,4-Di(2-cyanoisopropyl)-1,4-dihydrofullerene 1,4-(CMe₂CN)₂C₆₀ and 1,2-(CMe₂CN)(H)C₆₀ are stable in vacuo up to 513 K. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1935–1939, September, 2008.     

The thermodynamic properties of bis(η<Superscript>6</Superscript>-ethoxybenzene)chromium fulleride from <Emphasis Type="Italic">T</Emphasis> → 0 to 340 K

The temperature dependence of the heat capacity of crystalline bis-(η⁶-ethoxybenzene)chromium fulleride [(η⁶-(EtOPh))₂Cr]^·+[C₆₀]^·− was studied for the first time by adiabatic vacuum calorimetry over the temperature range 6–340 K with errors of ±0.2%. The temperature dependence of the EPR signal parameters of bis-(η⁶-ethoxybenzene)chromium fulleride was studied for the first time from 120 to 340 K. A reversible endothermic transformation was observed between 160 and 250 K during heating; it was caused by the dissociation of the [(C₆₀)₂]²⁻ dimer and the formation of the [(η⁶-(EtOPh))₂Cr]^·+[C₆₀]^·− fulleride; its standard thermodynamic characteristics were estimated and analyzed. The experimental data were used to calculate the standard thermodynamic functions, including the heat capacity, enthalpy, entropy, and Gibbs function of the fulleride dimer from T → 0 to 160 K and the [(η⁶-(EtOPh))₂Cr]^·+[C₆₀]^·− monomeric complex over the temperature range 250–340 K. The standard thermodynamic properties of the fulleride studied, fullerides studied earlier, and fullerite C₆₀ were compared.     

Electrochemical behavior and parameters of hydrofullerene C60H36

Electrochemistry of hydrofullerene C₆₀H₃₆ was studied by cyclic voltammetry in THF and CH₂Cl₂ in the −47–14 °C temperature range. Hydrofullerene undergoes reversible one-electron reduction to form a radical anion in THF (E ⁰=−3.18 V (Fc⁰/Fc⁺), Fc=ferrocene) and irreversible one-electron oxidation in CH₂Cl₂ (E _p ^a =1.22 V (Fc⁰/Fc⁺)). The reduction potential was used to estimate electron affinity of hydrofullerene as EA=−0.33 eV. It was suggested that C₆₀H₃₆ is an isomer withT-symmetry in which 12 double bonds form four isolated benzenoid rings located in vertices of an imaginary inscribed tetrahedron on the molecular surface. For hydrofullerene, the “electrochemical gap” is an analog of the energy gap (HOMO−LUMO), equal to (E ^Ox−E ^Red)=4.4 V, and indicates that C₆₀H₃₆ is a sufficiently “hard” molecule with a low reactivity in redox reactions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2083–2087, November, 1999.     

Thermodynamic characteristics of bis(η6-ethylbenzene)chromium fulleride

The temperature dependence of heat capacity of crystalline bis(η⁶-ethylbenzene)chromium fulleride [(η⁶-EtPh)₂Cr]^·+ [C₆₀]^·− was studied in adiabatic vacuum calorimeter in the range of 6.7 to 344 K with an error of ±0.3%. Dependence of the parameters of EPR signal of bis(η⁶-ethylbenzene)chromium fulleride on temperature was studied by electron paramagnetic resonance (EPR) in the range of 120 to 290 K. In the range of 204 to 246 K, upon heating, reversible endothermic transformation was recorded, which is caused by the dissociation of dimer (C₆₀⁻)₂ and formation of fulleride [(η⁶-EtPh)₂Cr]^·+ [C₆₀]^·−; its standard thermodynamic parameters were estimated and analyzed. Standard thermodynamic functions were calculated by the experimental data obtained: heat capacity, enthalpy, entropy, and Gibbs function of fulleride dimmer in the range of T → 0 to 204 K and monomer complex [(η⁶-EtPh)₂Cr]^·+ [C₆₀]^·− in the range of 246 to 344 K. Standard thermodynamic properties of fulleride under study, fullerides studied earlier, and fullerite C₆₀ were compared.     

Photochemical study of the zinc cis-3-(4-imidazolylphenyl)-1-(pyridin-2-yl)[60]fullereno[1,2-c]pyrrolidine-meso-tetraphenylporphyrinate dyad

Axial coordination of fullerenopyrrolidine bearing the donor imidazolyl group, cis-3-(4-imidazolylphenyl)-1-(pyridin-2-yl)[60]fullereno[1,2-c]pyrrolidine (C₆₀∼Im), with zinc meso-tetraphenylporphyrinate (ZnTPP) in an o-dichlorobenzene solution affords a non-covalently bonded donor-acceptor dyad ZnTPP-C₆₀∼Im. The photochemical behavior of the ZnTPP-C₆₀∼Im complex was studied by fluorescence (excitation at λ = 420 nm) and laser kinetic spectroscopy (excitation at λ = 532 nm, 12 ns). The formation constant of the 1: 1 porphyrin-fullerenopyrrolidine complex determined from quenching of ZnTPP fluorescence assuming static intracomplex quenching is 1.6·104 L mol⁻¹. Absorption spectra of the excited states in the system consisting of ZnTPP and Im∼C₆₀ (ZnTPP/C₆₀∼Im) were measured in solution from 380 to 1000 nm. The quenching constant of the triplet-excited ZnTPP with fullerenopyrrolidine C₆₀∼Im was determined. The results obtained indicate the formation of the triplet exciplex {PL}^* ⇌ {P^δ+…L^δ−} in the ZnTPP/C₆₀∼Im system upon laser photolysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1541–1547, September, 2006.     

Ab initio MO LCAO SCF simulation of molecular and electronic structure of η5-π-C60H5XCp (X=Fe, Si) complexes

The problem of existence of η⁵-π-complexes of unsubstituted fullereneI _h -C₆₀ and its cyclopentadienyl type derivative C₆₀H₅ ^. is discussed.Ab initio MO LCAO SCF calculations of hypothetical sandwich systems η⁵-π-C₆₀H₅XCp (X=Fe (1a), Si (1b)), the cationic complex C₆₀FeCp⁺ of unsubstituted C₆₀, and the C₆₀H₅ ^. radical were performed in the STO-3G and 3-21G basis sets. In the1a, 1b, and C₆₀H₅ ^. systems, hydrogen atoms are attached to carbon atoms of fullerenei _h -C₆₀ at α-positions relative to the same pentagonal face (pent ^*). In η⁵-complexes, XCp species are also coordinated to this face. According to calculations in the 3-21G basis set, the Fe-pent ^* bond energy in complex1a is much higher than those of similar bonds in1b and in the η⁵-π-C₆₀FECp⁺ cation (117 kcal mol⁻¹ vs. 37 and 64 kcal mol⁻¹, respectively) and is 7 kcal mol⁻¹ higher than the Fe−Cp bond energy in the classical sandwich system FeCp₂. The Fe…C _pent* and Fe…C_Cp distances in complex1a are slightly shorter than the Fe…C distance in the ferrocene molecule. The spin populations in the C₆₀H₅ ^. radical are almost completely localized on the atoms of thepent ^* face, which must favor the formation of η⁵-π-complexes of this radical. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1657–1662, September, 1999.     

Laser flash photolysis of fullerols of C60 and of C70 in aqueous solutions

Fullerols of C₆₀ and of C₇₀ [C₆₀(OH)_n, C₇₀(OH)_m], water-soluble fullerene derivatives, unlike some other fullerene derivatives (such as C₆₀ (C₄H₆O), C₆₀ (C₃H₇N) and C₆₀ [C(COOEt)₂]_x), do not result in excited triplet state but in ionization via monophotonic process in aqueous solutions with 248 nm laser. The quantum yields of formation of hydrated electron (Φ_e ⁻) are determined to be 0.08 and 0.11 for fullerols of C₆₀ and of C₇₀ respectively at room temperature (ca. 15°C) with KI solution used as reference. By laser flash photolysis and oxidation of sulfate radical anion SO₄ ⁻, the fullerol radical cation or neutral radical of C₆₀ is confirmed to be existent and the transient absorption spectra of fullerol radical cation of C₇₀ are observed for the first time. Project supported by the National Natural Science Foundation of China     

Generation of fullerenyl radicals and chemiluminescence in the (C<Subscript>60</Subscript>—R<Subscript>3</Subscript>Al)—O<Subscript>2</Subscript> system

Fullerenyl radicals (FR) RC₆₀ ^· and chemiluminescence (CL) are generated in the presence of O₂ in C₆₀—R₃Al (R = Et, Buⁱ) solutions in toluene (T = 298 K). The FR are formed due to the addition of the R^· radical, which is an intermediate of R₃Al autooxidation, to C₆₀. Mass spectroscopy and HPLC were used to identify Et_nC₆₀H_m (n, m = 1–6), Et_pC₆₀ (p = 2–6), and dimer EtC₆₀C₆₀Et as stable products of FR transformations. As found by ESR, the EtC₆₀ ^· radical (g = 2.0037) is also generated by photolysis of solutions obtained after interaction in the (C₆₀— R₃Al)—O₂ system. In the presence of dioxygen, the FR is not oxidized but yields complexes with O₂, which appear as broadening of the ESR signals. Chemiluminescence arising in the (C₆₀—R₃Al)—O₂ system is much brighter (I _max = 1.86·10⁸ photon s⁻¹ mL⁻¹) than the known background CL (I _max = 6.0·10⁶ photon s⁻¹ mL⁻¹) for the autooxidation of R₃Al and is localized in a longer-wavelength spectral region (λ_max = 617 and 664 nm). This CL is generated as a result of energy transfer from the primary emitter ³CH₃CHO* to the products of FR transformation: R_nC₆₀H_m, R_pC₆₀, and EtC₆₀C₆₀Et. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 205–213, February, 2007.     

Solvent Effects on Ion-Pair Distribution and Dimerization of Tetraalkylammonium Salts

Summary.  The distribution of tetraalkylammonium ions (C _n H _2n+1 )₄N⁺ (R ⁺, TAAn ⁺, n = 4–7) with picrate ion (pic ⁻) and inorganic anions X ⁻, (Cl⁻, Br⁻, ClO⁻ ₄), into various inert organic solvents was studied at 25.0°C. The distribution data were analyzed by taking into consideration the distribution of ion pairs, R ⁺ · X ⁻, and the dimerization of the ion pairs, (R ⁺ · X ⁻)₂, in the organic phase. The ion-pair, distribution constant, K _dist, increases with increasing chain length of the tetraalkylammonium ion and with increasing ionic radius of the anion. The values of K _dist show a good correlation with the E _T value of solvent, i.e. the solvation ability with respect to the anion, and smoothly increase with increasing E _T. The effect of the solvent on the dimerization constants, K _dim, is markedly different between the ion pairs of picrate ion and inorganic anions. In the case of picrate, K _dim significantly decreases with decreasing length of the alkyl chain of the tetraalkylammonium ion, but hardly changes by changing the solvent. On the other hand, in the case of ion pairs of inorganic anions the value of K _dim decreases with decreasing E _T and is almost constant for all anions. These results were reasonably explained by the difference of the solvation of the anion moieties of the monomeric and dimeric ion pairs. Received May 15, 2001. Accepted (revised) July 18, 2001     

Direct observation of geminate recombination within photochemically produced ion pairs in polar solutions

Pulsed laser excitation of pyrene (P)/N, N-diethylaniline (DEA) solutions in methanol at low temperatures leads to the generation of the P^? and DEA⁺ radical ions. A fast initial decay of the ions (τ_{$\text{1}\text{2}$} ≈ 37 nsec at ?40°C) is observed and is attributed to geminate recombination within the initially formed (²P^?…²DEA⁺) ion pair. The quenching of ¹P^*) by DEA is also associated with substantial intersystem crossing, yielding ³P^*. The data rule out both gemiate and non-geminate (homogeneous) inonic recombinations as sources for the initial yield of ³P^*, in keeping with a prompt triplet formation mechanism.     

Solvent Effects on Ion-Pair Distribution and Dimerization of Tetraalkylammonium Salts

 The distribution of tetraalkylammonium ions (C _n H _2n+1 )₄N⁺ (R ⁺, TAAn ⁺, n = 4–7) with picrate ion (pic ⁻) and inorganic anions X ⁻, (Cl⁻, Br⁻, ClO⁻ ₄), into various inert organic solvents was studied at 25.0°C. The distribution data were analyzed by taking into consideration the distribution of ion pairs, R ⁺ · X ⁻, and the dimerization of the ion pairs, (R ⁺ · X ⁻)₂, in the organic phase. The ion-pair, distribution constant, K _dist, increases with increasing chain length of the tetraalkylammonium ion and with increasing ionic radius of the anion. The values of K _dist show a good correlation with the E _T value of solvent, i.e. the solvation ability with respect to the anion, and smoothly increase with increasing E _T. The effect of the solvent on the dimerization constants, K _dim, is markedly different between the ion pairs of picrate ion and inorganic anions. In the case of picrate, K _dim significantly decreases with decreasing length of the alkyl chain of the tetraalkylammonium ion, but hardly changes by changing the solvent. On the other hand, in the case of ion pairs of inorganic anions the value of K _dim decreases with decreasing E _T and is almost constant for all anions. These results were reasonably explained by the difference of the solvation of the anion moieties of the monomeric and dimeric ion pairs.     

Redox-induced hydrogen transfer from hydrofullerene C60H36 to fullerene C60

The possibility of hydrogen transfer from hydrofullerene C₆₀H₃₆ to electrogenerated radical anion C₆₀ ^.− or dianion C₆₀ ²⁻ in propylene carbonate-toluence (3∶2, v/v) was demonstrated by cyclic voltammetry. The process affords C₆₀H₂ as the product. The reaction found is the typical redox-induced process. Translated fromIzvestiya Akodemii Nauk. Seriya Khimicheskaya, No. 6, pp. 1136–1139, June, 1998.