Laser Photolysis Study on Mechanism and Efficiency of Electron Transfer Between Fullerenes (C60 and C70) and Tetraselenafulvalenes

Efficient electron-transfer reactions from three kind of tetraselenafulvalenes (TSeF's) to photoexcited triplet state of C₆₀ or C₇₀ in polar solvents have been confirmed by transient absorption spectroscopy observing the decay of ³C₆₀*/³C₇₀* and rise of C₆₀^-•/C₇₀^-•. Growth of single crystal seems to be stimulated by laser irradiation of the solution containing C₆₀ and bis(ethylenedithio)tetraselena-fulvalene (BEDT-TSeF), in which C₆₀^-• was effectively formed.     

Synthesis of Radiolabeled Fullerenes C60 and C70

The synthesis of radiolabeled C₆₀/C₇₀ for potential biochemical tracer studies was carried out. Vaporization under plasma are conditions (~3000C) of graphite rods impregnated with the ¹⁴C labeled steroid progesterone generates the expected C₆₀/C₇₀ mixture. Isolation and characterization of the ¹⁴C-C₆₀ is reported. Interestingly, the C₇₀ had more radioactivity than the C₆₀.     

Synthesis of Radiolabeled Fullerenes C60 and C70

Abstract

The synthesis of radiolabeled C₆₀/C₇₀ for potential biochemical tracer studies was carried out. Vaporization under plasma are conditions (~3000C) of graphite rods impregnated with the ¹⁴C labeled steroid progesterone generates the expected C₆₀/C₇₀ mixture. Isolation and characterization of the ¹⁴C-C₆₀ is reported. Interestingly, the C₇₀ had more radioactivity than the C₆₀.     

Synthesis and Properties of Platinum Complexes of Fullerenes (C60 and C70)

Platinum complexes of C60 and C70 were synthesized and characterized by using spectroscopic analysis. The X-ray data of the C60-platinum complex containing no solvent of crystallization afforded the definite bond lengths and angles.     

Raman Spectra of Chlorinated C60 and C70 Fullerenes

Raman spectra of chlorinated C₆₀ and C₇₀ fullerenes prepared by photochlorination have been reported and discussed. The Raman lines suggest structural analogies with already fully characterized brominated fullerenes. Intense laser light irradiation cause a decomposition of fullerene chloro-derivatives leading to the formation of C₆₀ polymer.     

Raman Spectra of Chlorinated C60 and C70 Fullerenes

Abstract

Raman spectra of chlorinated C₆₀ and C₇₀ fullerenes prepared by photochlorination have been reported and discussed. The Raman lines suggest structural analogies with already fully characterized brominated fullerenes. Intense laser light irradiation cause a decomposition of fullerene chloro-derivatives leading to the formation of C₆₀ polymer.     

A Remark on Intramolecular Transfer of an Injected Electron in C60 and C70

A simple analysis on the intramolecular transfer of an injected electron into C₆₀ and C₇₀ has been performed based on the concept of orbital interaction. This analysis contains the partitioning of each fullerene into three parts and the examination of the frontier molecular orbital interaction for propagation of an injected electron into the whole Cgo or C70 molecule. This electron transfer process is shown to be “one-way” from energetical point of view.     

A Remark on Intramolecular Transfer of an Injected Electron in C60 and C70

Abstract

A simple analysis on the intramolecular transfer of an injected electron into C₆₀ and C₇₀ has been performed based on the concept of orbital interaction. This analysis contains the partitioning of each fullerene into three parts and the examination of the frontier molecular orbital interaction for propagation of an injected electron into the whole Cgo or C70 molecule. This electron transfer process is shown to be “one-way” from energetical point of view.     

Localized Molecular Orbital Studies of Fullerenes: C60 and C70

Localized molecular orbitals (LMOs) have been calculated for C₆₀ and C₇₀ by using the CNDO/2 approximation and the energy-localization scheme of Edmiston-Ruedenberg. It is found that the π-bonding on the surfaces of the spherical carbon cages is localized into two-centered two-electron (2c2e) and three-centered two-electron (3c2e) bonds with additional charge distributions delocalized in the neighboring atoms. The localized electronic structures, the hybridized states of carbon atoms, the spherical aromaticity, and the reactivity for forming metal complexes of C₆₀ and C₇₀ are discussed.     

Effect of Molecular Rotation on Vapor Phase Nucleation: Fullerenes C60 and C70

Abstract

The effect of rotational free energy of fullerenes C₆₀ and C₇₀ on homogeneous nucleation of crystals from vapor phase have been studied. Classical nucleation parameters have been estimated for the case of nucleation and crystal growth of C₆₀ and C₇₀ by Physical Vapor Transport (PVT) method under different supercooling in the range of 20–150 K, keeping the source temperatures constant. The result shows that the growth of large size single crystals is more feasible in the lower supercooling range. The effect of change in interfacial tension on the critical free energy of formation of the nuclei is also studied.     

Ozone Reaction with C70 and C60 Fullerenes: The Effect of Temperature on the Reaction Kinetics

It has been confirmed that the effect of temperature on the rate constants (k) of ozone reaction with C₇₀ and C₆₀ fullerenes follows the Arrhenius law. The experimental values of activation energy (E_a) and pre-exponential factor (A), like as those of other simple alkenes, are in the order of 2.4-2.6 kcal mol^-1 and (1.2-1.8) × 10⁷ L mol^-1 sec^-1, respectively. They are practically equal for the both fullerenes. It has also been found that the value of the rate constant k of C₇₀ fullerene ozonolysis is higher in comparison to the respective k-value of C₆₀.     

Thermolysis and Photolysis of C60 Diozonides

Ozonation of C₆₀ in o-xylene produced three C₆₀(O₃)₂ diozonides that were separated from one another and from two C₆₀(O₃)₃ triozonides by High Performance Liquid Chromatography (HPLC). Upon thermolysis at 10, 15, and 16.6°C, each of the diozonides dissociated sequentially, first to a C₆₀O(O₃) oxyozonide, then to a C₆₀O₂ diepoxide. The three diepoxides were stable in solution for at least 3 weeks. The mean lifetimes of the three diozonides were 52 ± 5, 62 ± 6, and 17.3 ± 1.8 min, respectively (all at 15°C). The mean lifetimes of the three oxyozonides were 69.7 ± 0.7 and 58 ± 6 min at 16.6°C, respectively and about 240 min at 10°C. Photolysis of the diozonides yielded two dioxidoannulenes with UV-Vis adsorption maxima at 333 and 332 nm, and what appeared to be an epoxide-oxidoannulene with UV-Vis adsorption maximum at 327 nm. These annulenes were observed to form dimers. We have synthesized and characterized six C₆₀O₂ dioxides, at least three and possibly four of which were hitherto unknown. We report the discovery of oxyozonides that form during the dissociation of diozonides.     

Solubility of Fullerenes C60 and C70 in Seven Normal Alcohols and Their Deduced Solubility in Water

Abstract

The solubilities of C₆₀ and C₇₀ at 25°C in seven normal alcohols obey the relationship InY = a + bX + cX², where Y is solubility and X is the Hildebrand solubility parameter of the solvent. Extrapolation to the solubility parameter of water yields solubilities in water of 1.3′10^?11 (C₆₀) and 1.3′10^?10(C₇₀) ng/ml with an uncertainty of one order of magnitude.     

Fullerenes C60 and C70: a model for solubility by applying the correlation intensity index

Abstract

Fullerenes are materials which have many applications as in the field of chemical technology as well as in the field of biochemistry and medicine. Solubility of fullerenes in different solvents has been studied many times in the field of computational chemistry. However, analysis of different approaches which able help to solve the task of prediction of solubility fullerenes remains attractive and very important direction of scientific activity. The correlation intensity index (CII) is a new criterion of the predictive potential of models. The applying of CII together with Index of Ideality Correlation (IIC) in modeling of fullerenes solubility in various solvents by the Monte Carlo method using the CORAL software (http://www.insilico.eu/coral) indicates that applying of the CII improves the predictive potential of these models. These models can be applied for systematization of ecological, biochemical, and medicinal knowledge related to applying of fullerenes. This systematization gradually becomes a factor of key importance, since the applying of the fullerenes expanded day by day.     

Structural Analogies and Differences Between Graphite Oxide and C60 and C70 Polymeric Oxides (Fullerene Ozopolymers)

A brief survey of the chemical structural analogies and differences between graphite oxide and fullerene ozopolymers or polymeric fullerene oxides (PFO) is presented. Graphite oxide is the product of oxidation of graphite prepared with strong oxidizing agents while PFO is the products formed by prolonged ozonation of C₆₀ or C₇₀ in solution. Notwithstanding the different starting substrates and oxidation conditions, elemental analyses, FT-IR spectroscopy and ¹³C-NMR spectroscopy suggest a very similar chemical structure for graphite oxide and PFO. A further analogy is the possibility to perform reduction or oxidation reactions on both substrates considered. Graphite oxide and PFO have also in common the ability to act as ion exchangers and as metal ion binders. Even the thermal behavior is comparable. However, X-ray powder diffraction has confirmed that graphite oxide still has a layered structure derived from graphite but with the graphene sheets at much bigger distance from each other due to the intercalation of oxidized groups and solvent molecules, while PFO do not show at all any sign of layered structure either from the X-ray spectra and also by its behavior in solution which is strikingly different from that shown by graphite oxide.     

Solubility of Fullerenes C60 and C70 in Seven Normal Alcohols and Their Deduced Solubility in Water

The solubilities of C₆₀ and C₇₀ at 25°C in seven normal alcohols obey the relationship InY = a + bX + cX², where Y is solubility and X is the Hildebrand solubility parameter of the solvent. Extrapolation to the solubility parameter of water yields solubilities in water of 1.3'10^-11 (C₆₀) and 1.3'10^-10(C₇₀) ng/ml with an uncertainty of one order of magnitude.     

Ferrocene Derivatives in Diels-Alder [4+2] Cycloaddition Reactions to Fullerenes C60 and C70

The synthesis and characterization of adducts of C₆₀ and C₇₀ with diene 5 is described. When 5 was reacted with fullerene C₆₀, a mixture of mono 7 and bisadduct 8 was found, while with C₇₀ a novel monoadduct 9 was formed.     

C_（60）／C_（70）在有机－无机凝胶中的光谱特性

本文介绍了把Ｃ６０／Ｃ７０成功地掺入到几种有机一无机凝胶中的工艺过程，测定了样品的吸收谱，激发谱和荧光谱。以５３２ｎｍ为激发光源，在６５０ｎｍ，６８０ｎｍ波段左右获得比在甲苯溶液中强得多的荧光效应。     

Structural (XRD and HRTEM) investigations of fullerite C60 and C70 samples

Since the carbon states on the basis of C₆₀ and C₇₀ exhibit very interesting physical properties such as hardness exceeding diamond, we focused our investigations on the comparison of structures of the C₆₀ and C₇₀ hard phases synthesized at high pressure and high temperatures. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) investigations have revealed that two states (amorphous and nanocrystalline) co-exist in samples of both kinds of fullerites. The difference between the diffraction patterns of C₆₀ and C₇₀ has been ascribed mainly to the grade of disorder. The XRD and HRTEM results have been correlated with the transport properties (electrical and thermal conductivity) of the samples.     

Combustion Calorimetric Studies on C60 and C70

Combustion calorimetric studies on C₆₀ and C₇₀ were made using a new micro-bomb combustion calorimeter. Standard enthalpies of formation at 298.15 K were determined to be (2273±15) kJ·mol^-1 and (2375±18) kJ·mol^-1 for C₆₀ and C₇₀, respectively.