Improved Spectrophotometric Analysis of Fullerenes C60 and C70 in High-solubility Organic Solvents

Abstract

Fullerenes are among a number of recently discovered carbon allotropes that exhibit unique and versatile properties. The analysis of these materials is of great importance and interest. We present previously unreported spectroscopic data for C60 and C70 fullerenes in high-solubility solvents, including error bounds, so as to allow reliable colorimetric analysis of these materials. The Beer-Lambert-Bouguer law is found to be valid at all wavelengths. The measured data were highly reproducible, and yielded high-precision molar absorbance coefficients for C60 and C70 in o-xylene and o-dichlorobenzene, which both exhibit a high solubility for these fullerenes, and offer the prospect of improved extraction efficiency. A photometric method for a C60/C70 mixture analysis was validated with standard mixtures, and subsequently improved for real samples by correcting for light scattering, using a power-law fit. The method was successfully applied to the analysis of C60/C70 mixtures extracted from fullerene soot.

[60]Fullerene for Medicinal Purposes, A Purity Criterion towards Regulatory Considerations

“…Figure 6A shows the representative UV-Vis spectrum of a toluene solution of the studied samples. The observed spectral features agree with those previously observed by other authors [37,38]. The absence of absorption bands at 424 nm and 496 nm, characteristic of C 60 O [39], clearly indicates that this impurity can only be present at concentrations below the limit of detection.…”

The Effects of Temperature and Humidity on the Microstructure of Sulfonated Syndiotactic–polystyrene Ionic Membranes

“…The characteristic absorption features of s–sPS (sample A) occur below 300 nm while above this value the absorbance falls quickly off. Pure C60 exhibits two maxima at 335 and 408 nm [ 43 ]. These features are well displayed by the spectrum from the sPS–C60 composite membrane after casting (blue curve).…”

Interactions between fullerene derivatives and biological systems

“…Fullerene materials represent promising PDT photosensitizers, as it shows very efficient ISC that is conserved in a variety of fullerene derivatives. 26 Furthermore, while the bare fullerene cage shows weak absorption in the Vis-NIR region, 3 it can be functionalized with chromophores to form dyads that participate in chromophore-to-fullerene energy transfer. Accordingly, the development of efficient photosensitizers requires attention to several parameters such as absorption wavelength, absorption intensity, triplet state population, triplet state lifetime, and mechanism of ROS generation (type I or type II).…”

“…In ideal PDT photosensitizers, the system should absorb visible light to avoid the penetration limitations and cytotoxicity of shorter wavelength light. To circumvent its poor absorption, 3 C 60 has been modified with a chromophore. 26 After chromophore excitation, efficient energy transfer is observed from it to the fullerene cage, promoting the cage into an excited state and allowing it to undergo ISC and generate ROS.…”

“…In contrast to its physical and electronic properties, the biological activity of fullerene materials was initially limited in its investigation due to poor aqueous compatibility 2 and weak absorption of visible light. 3 The report of water-soluble fullerene systems opened various avenues of its biological study and many works have taken advantage of its properties for uses in MR imaging, 4,5 drug delivery, 6,7 antiviral and antibacterial defense, 8,9 antioxidative and anti-inflammatory therapy, [10][11][12] photodynamic therapy (PDT), [13][14][15] and tumor targeting 16,17 (Fig. 1).…”