UV spectroscopy of monosubstituted derivatives of 1,2-dihydro-C60-fullerenes

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

“…Molar-absorption coefficients for C60 found in the literature are compared with measured values in Table 2. 6,7,11,12 The previously reported data is scarce, and deviates from our values. These literature values might be considered to be less reliable due to the fact that either fewer or only single calibration points were used; the fullerenes used were not equally pure; the pathlength was not varied; the dilution reliability was possibly not as accurately analyzed and corrected for by mass; the fullerene solubility limits where not carefully considered and/or the sample temperature was not controlled.…”

“…The profile of the absorption spectra for C60 in o-DCB and o-xylene and for C70 in o-xylene agree well with the literature. 6,23 As previously reported for a range of aromatic solvents, the absorption spectra of both fullerenes are nearly independent of solvent type above 450 nm, but deviate more noticeably below 450 nm. 23 Differences between spectra cannot simply be explained by experimental error and represent a real deviation due to solvent effects.…”

“…The model spectra exhibited a very poor fit to the measured spectra, with large deviations between the measured data points and the lines of best fit (as exemplified in Fig. 3), indicating that the model is not appropriate for (12) 47000 (7) 4040 (12) 957 (12) 834 (12) 47780 ± 407 50390 ± 411 5788 ± 91 852 ± 14 786 ± 13 331 333 400 410 470 66845 (12) 54523 (6) 2590 (12) 3170 (11) 616 (11) 56270 ± 557 59960 ± 610 2692 ± 18 2364 ± 15 394 ± 4 515 520 570 580 600 1022 (12) 979 (11) 938 (12) 786 (11) 887 (11) 777 ± 6 810 ± 6 724 ± 5 685 ± 5 792 ± 6 analyzing the extracted mixtures. A simple baseline correction for these samples would have been incorrect because the off-set did not represent a drift in instrumental response, nor a simple baseline error, but rather a physical interference due to the scattering of light by microscopic particles (which depends on the wavelength).…”

“…For the limited data that does exist in the literature, there are inconsistencies in the molar-absorption coefficients presented, and no indication of uncertainty or errors is provided. 6,7,11,12 Here, we characterize C60 and C70 in o-xylene and o-DCB with UV/Vis-spectrometry at 320 to 800 nm, demonstrate the validity of the Beer-Lambert-Bouguer law and determine accurate molar-absorption coefficients with confidence limits. By closing the literature gap, we give researchers the means to determine mixtures of C60 and C70 in either o-xylene or o-DCB spectroscopically.…”

“…LC/UV). [3][4][5][6] The distinct absorbance features of the most abundant fullerenes, C60 and C70, has made UV/Vis-spectroscopy a powerful analysis tool, since it is a fast, cheap and reliable detection method and this even for C60/C70-mixtures from direct soot extraction. 3,4,7,8 The accuracy of such colorimetric mixture analyses rely on the extraction efficiency and the reliability of molar-absorption coefficients used, the values of which vary with the solvent type.…”