Chromophore‐Appended C ₆₀ and C ₇₀ Fullerenes: Anthracene and Pyrene Derivatives – Syntheses, Cyclic Voltammetry, and Spectra

Fluorophore(s) Appended Fullerene Dyads and Triads for Probing Photoinduced Energy Transfer: Syntheses, Electronic Structure, and Fluorescence Studies

“…The emission intensity of the 715 nm band was found to be much higher than that of 6 under similar experimental conditions. The occurrence of excited energy transfer in the dyad 3 paralleled the observations reported earlier in the case of pyrene appended fullerene dyads (Nakamura et al 1995;Schwenninger et al 1997;Gareis et al 1998;Kordatos et al 2001;Fujitsuka et al 2002;Martin et al 2003a, b). The fluorescence studies on triads 1 and 2 revealed interesting behavior.…”

“…A number of fullerene derivatives linked either to porphyrin, phthalocyanine, or ruthenium polypyridyl donor entities have been synthesized and photoinduced electron transfer has been studied (Imahori and Sakata 1997;Guldi and Kamat 2000;Guldi and Prato 2000;Gust and Moore 2000;El-Khouly et al 2004). However, studies on fullerene derivatives appended with energy donor fluorophore entities have been scarce (Nakamura et al 1995;Schwenninger et al 1997;Gareis et al 1998;Kordatos et al 2001;Fujitsuka et al 2002;Martin et al 2003) even though in the fluorophore-fullerene dyads the fullerene molecule can act as an excellent excited state energy acceptor because of its low excited-state energy (absorption extending near-IR region) (Sun 1997). The excitedstate chemistry is expected to be favored in fluorophore-functionalized fullerene systems because of the 'antenna effect' provided by the appended fluorophores.…”

“…The excitedstate chemistry is expected to be favored in fluorophore-functionalized fullerene systems because of the 'antenna effect' provided by the appended fluorophores. Among the different available fluorophores, pyrene is most commonly used to build fluorophore-fullerene dyads in the literature (Nakamura et al 1995;Schwenninger et al 1997;Gareis et al 1998;Kordatos et al 2001;Fujitsuka et al 2002;Martin et al 2003a, b).…”

Cycloadditions

“…Similar conditions were employed to append the chromophore pyrene to C 60 in 41% yield [95]. Reaction of 94 with an acid bromide yields almost quantitatively the bromo compound 96 [96].…”

Photoinduced electron transfer in fullerene triads bearing pyrene and fluorene

“…In order to probe photoinduced electron transfer, photosensitizing electron donors like porphyrin, phthalocyanine, or ruthenium polypyridyl were covalently linked to fullerene and studies were performed in a number of organic solvents [1][2][3][4]. Similarly, for probing photoinduced energy transfer, often pyrene as a fluorophore was covalently linked to fullerene [7][8][9][10][11][12][13][14]. In the latter studies, fullerene is shown to be an excellent excited-state energy acceptor because of its low excitedstate energy (absorption extending into the near-IR region) and the fluorophore provided an 'antenna effect' by channeling the excited energy to the fullerene entity.…”