C70 fullerene

OhtsukI T, Ohno K, Shiga K, Kawazoe Y, Maruyama Y and Masumoto K 1998 Insertion of Xe and Kr atoms Into C60 and C70 fullerenes and the formation of dimers Phys. Rev. Lett. 81 967-70... 

The H C ratio in hydrocarbons is indicative of the hydrogen deficiency of the system. As mentioned, the highest theoretical H C ratio possible for hydrocarbon is 4 (in CH4), although in electron-deficient carbocationic compounds such as CH5 and even CH/, the ratio is further increased (to 5 and 6, respectively, see Chapter 10). On the other end of the scale in extreme cases, such as the dihydro- or methylene derivatives of recently discovered Cgo and C70 fullerenes, the H C ratio can be as low as 0.03. 

This paper is concerned with the structures of the simplest possible adducts of the Ceo and C70 fullerenes, namely the monohydrides, CmH and C H. These open shell species or radicals may be considered as the product of the addition of one atom of hydrogen or one of its isotopes, among which we include specifically the light pseudoisotope of hydrogen known as muonium. Mu = pfe. Although Ceo//has been observed [1], the stimulus for these calculations arose from the experiments on muon implantation in solid [2,3] and C70 [4]. 

Farre M, Perez S, Gajda-Schrantz K, Osorio V, Kantiani L, Ginebreda A, Barcelo D (2010) First determination of C60 and C70 fullerenes and N-methylfulleropyrrolidine C60 on the suspended material of wastewater effluents by liquid chromatography hybrid quadrupole linear ion trap tandem mass spectrometry. J Hydrol 383(l-2) 44-51... 

Langa et al. [26, 59, 60], while conducting the cycloaddition of N-methylazo-methine ylide with C70 fullerene, proposed a rather similar approach. Theoretical calculations predict an asynchronous mechanism, suggesting that this phenomenon can be explained by considering that, under kinetic control, microwave irradiation will favor the more polar path corresponding to the hardest transition state . 

In the same way as for Ceo and C70 fullerenes, boron clusters with magic numbers B5+ and Bi3+ appear as prominent peaks in mass spectra. These boron clusters were calculated for various geometries by several authors and were considered to present 3D aromatic stabilization.297-299... 

Krakovjak MG, Anufrieva EV, Anan eva TD et al. (2006) Water-soluble complexes of poly(N-vinylamides) of various structures with C60 and C70 fullerenes. Polym Sci Ser A. 48 590-595. 

Abstract The biological effects of fullerenes and, in particular, of C60 have been recognized since long time. One of the problems which hindered the application of fullerenes in medicinal chemistry regards their insolubility in water and water-based fluids. In the present chapter it is reported that C60 and C70 fullerenes are soluble in vegetable oils, in general, in esters of fatty acids and in free fatty acids. These results pave the way in the utilization of vegetable oils as vehicles in the delivery of fullerenes for both topical applications and internal use (e.g., intramuscular injection). 

Despite the numerous modelling works on the subject (e.g. Sivaraman et al., 2001 Huang, 2005) and the great interest on the solubility of fullerenes in hydrophilic solvents, in water and in biologically active solvents for the potential application of fullerenes as drugs, none was able to predict that C60 and C70 fullerenes... 

This chapter shows that the solubility of C60 and C70 fullerenes can be predicted from the solubility parameter of these two molecules and the calculated solubility parameters of fatty acids and their esters. Furthermore, the solubility of C60 and C70 fullerenes in a series of vegetable oils and fatty acid esters will be presented and discussed. 

Fig. 13.1 The solubility of C60 and C70 fullerene is maximum in vegetable oils with lower level of unsaturation (i.e. number of double bonds) and decreases as the insaturation level grows. Having a peculiar chemical structure, castor oil cannot be included in the correlation rule (See Color Plates)...

The solubility of C60 and C70 fullerenes in vegetable oils will permit to employ these molecules for topical use in creams, lotions and ointments, which are adsorbed by skin. Vegetable oils, especially olive oil, are considered excellent excipients for injectable preparation where the active principle is soluble in fats. Their absorption in the subcutaneous tissues is slow and limited and ensures a gradual release of the active principle (Adami, 1960). 

A theoretical justification of the surprising solubility of C60 and C70 fullerenes in vegetable oils has been proposed in terms of solubility parameter of fullerenes and vegetable oils. It has been shown that the solubility parameter of C60 and C70 fullerenes can be calculated by a group increment approach following Van Krevelen... 

AMI semiempirical calculations show that, in the gas phase, the reactivity of C70 fullerene with butadiene is only slightly greater than that of C6o- However, in toluene,... 

More recently, the same research group showed that the same silylene, Dip2Si , added in a similar manner to the C70 fullerene to yield the related silacyclopropane202. 

C60 and C70 fullerenes were obtained from Southern Chemical L.L.C. and were both 99.9+% pure grade. Toluene and n-hexane were purchased from Aldrich as well as DC1 37% in D20 (deuterium enrichment 99%). Zn dust was from Aldrich as well and was characterized by a particle size <10 pm. 

Fig. 7.4 FT-IR spectra (in KBr) (top) perdeuterated C70 fullerene C70D38 showing the C-D stretching bands at 2,161 and 2,108 cm-1 the features at 2,915 and 2,850 cm-1 are due to residual C-H stretching. The spectra in the middle and at the bottom of the figure are due to C7QI I i8 synthesized respectively in toluene and in benzene...

The hydrogenated C70 fullerenes C70H38 and C70D38 have been photolyzed at 254 nm under Ar or He flow. The photolysis rate constant have been measured k = 1.54 x 10-3 s 1 for C70H38 while the photolysis of C70D3g occurs at a rate of 1.17 x 10-3 s-1. A remarkable isotope effect in the photolysis of the two molecules has been... 

C60 and C70 fullerenes were obtained from MTR and was 99.95% pure grade. n-Hexane (HPLC grade) tetradecane (special grade granted without olefins) and HC1 37% were obtained from Aldrich as well as the deuterium chloride (DC1) 37%... 

All the infrared spectra of the present study have been made on samples embedded in KBr matrix and all data were extrapolated to 0 K. These spectral data at extremely low temperatures are of paramount importance for astrochemical search of these molecules in space. By comparing the gas phase spectra of both C60 and C70 fullerenes extrapolated to 0 K with the data taken in KBr matrix, it has been found that at 0 K the entity of the band shift due to matrix effect is 5-10 cm-1 toward lower frequencies. In other words, the gas phase spectral bands are systematically shifted 5-10 cm 1 toward higher frequencies than the same bands recorded in KBr. Instead, the matrix effect becomes quite negligible when the spectral data taken in KBr are extrapolated to >1,000 K. In such case there is a fair agreement between the band position of C60 and C70 fullerenes in the gas phase and the extrapolation from data taken in KBr matrix. 

The vibrational spectroscopy of C60 and C70 fullerenes has been investigated in numerous papers and reviewed by Kuzmany et al. 1995 Kuzmany and Winter 2000. Much less attention has been dedicated to the low temperature spectra of these two molecules and there are no reports at all concerning the low temperature spectra of fulleranes in general and in particular to the most stable fullerane... 

The present chapter is therefore dedicated to review the low temperature infrared spectroscopy of C60 and C70 fullerenes, C60H18 fullerane (one of the most stable hydrogenated derivative of fullerenes) and a mixture of hydrogenated fullerenes referred collectively as C60H/C70Hy. Additionally, also the gas phase spectra of C60 and C70 fullerenes will be shortly reviewed. 

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