Photophysical and Electron-Transfer Properties of Mono- and Multiple-Functionalized Fullerene Derivatives

Abstract

Mono-and multiple-functionalized C 60 derivatives were synthesized and studied for their photophysical properties. Electronic absorption spectra and absorptivities of the C 60 derivatives in solution were measured and compared. By recording the fluorescence spectra using a near-infrared-sensitive emission spectrometer, we quantitatively determined fluorescence quantum yields of the C 60 derivatives. For the mono-functionalized C 60 derivatives, the compound with a [5,6]-open fulleroid addition pattern on the fullerene cage appeared to be considerably less fluorescent than those with a [6,6]-closed cage addition pattern. Despite the disturbance of the electronic structure via multiple additions to the fullerene cage, the multiple-functionalized C 60 derivatives exhibited no dramatic changes in fluorescence quantum yields in comparison with the mono-functionalized C 60 derivatives. The fluorescence lifetimes of the C 60 derivatives, obtained using the time-correlated single photon-counting technique, were all in the range of 1-3 ns. In addition, the dependencies of the fluorescence intensities and lifetimes of the C 60 derivatives on the concentration of the quencher N,N-diethylaniline (DEA) were evaluated. Apparently, upon photoexcitation, even the C 60 derivatives with a hexa-functionalized fullerene cage underwent significant electron-transfer interactions with the electron donor DEA, resulting in efficient fluorescence quenching. In a polar solvent, the contribution of static quenching also became important. The results for different derivatives and their molecular structural and mechanistic significance are discussed.

Nucleophilic cyclopropanation of [60]fullerene by the addition–elimination mechanism

“…The principal possibility of using a,b-dibromo derivatives of acid esters in the Bingel reaction was demonstrated by synthesizing methanofullerene 35 (Scheme 11). 35 In a search for highly water-soluble fullerene derivatives, condensation of equimolar amounts of a bromomalonodiamide derivative and C 60 gave adduct 36, 36 hydrolysis of which resulted in methanofullerene 37 (Scheme 12). However, neither tetraacetate 36 nor even tetraol 37 showed any noticeable water solubility.…”

Fullerene Sugar Balls: A New Class of Biologically Active Fullerene Derivatives

“…Applications of such compounds are therefore not limited by their availability. In addition, hexa‐substituted fullerene derivatives are only weak electron acceptors34 and no longer efficient singlet oxygen sensitizers 35. Therefore, problems associated with the phototoxicity of mono‐ or di‐substituted fullerene derivatives36 resulting from the production of ROS are prevented in the case of hexasubstituted derivatives.…”

Synthesis and Optical Properties of Double Antenna Pyrene-OPV- Fullerene C60

“…This fact, however, does not mean necessarily that there is no emission from fullerene. In fact, it is well demonstrated that the quantum yield of fullerene derivatives is very low (17), and consequently it is reasonable to consider that the residual pyrene-OPV emission covers the fullerene one due to the difference in several orders of magnitude of the relative quantum yields (12). The fluorescence quantum yield of the pyrene OPV-aldehydes is around 30-40%.…”