Large Substituent Effect on the Photochemical Rearrangement of 1,6-(<i>N</i>-Aryl)aza-[60]fulleroids to 1,2-(<i>N</i>-Arylaziridino)-[60]fullerenes
作者:Akihiko Ouchi、Ryota Hatsuda、Bahlul Z. S. Awen、Masako Sakuragi、Reiko Ogura、Tadahiro Ishii、Yasuyuki Araki、Osamu Ito
DOI:10.1021/ja0267728
日期:2002.11.1
Large substituenteffects were observed in the rates and reaction mechanisms of the photochemical rearrangement of N-arylaza-[60]fulleroid 1 to N-arylaziridino-[60]fullerene 2, in which the difference of the rates between the fastest and the slowest (>2160-fold) was attained only by changing the aryl group from 1-naphthyl to 2-naphthyl. The decreasing order of the reaction rates in relation to the
Remote Control on the Photochemical Rearrangement of 1,6-(<i>N</i>-Aryl)aza-[60]fulleroids to 1,2-(<i>N</i>-Arylaziridino)-[60]fullerenes by <i>N</i>-Substituted Aryl Groups
作者:Akihiko Ouchi、Bahlul Z. S. Awen、Ryota Hatsuda、Reiko Ogura、Tadahiro Ishii、Yasuyuki Araki、Osamu Ito
DOI:10.1021/jp0472717
日期:2004.11.1
Photochemical rearrangement of 1,6-(N-aryl)aza-[60]fulleroids (1) to 1,2-(N-arylaziridino)-[60]fullerenes (2) depends on the N-aryl substituents remote from the reaction center. A systematic kinetic study of the N-substituents discloses a decrease in the reaction rates of the photochemical rearrangement in the order 1-naphthyl (1b) > 1-pyrenyl (1d) > phenyl (1a) > 2-naphthyl (1c). The large substituent effect in the rates, which vary by ca. 2200-fold, is interpreted in terms of changes in the reaction mechanisms. The fast photochemical rearrangement of derivatives 1b,d proceeds through the normal triplet states of 1; in the case of 1b, triplet sensitization by the product 2b also operates. For the slow rearrangement rates of la,c, nanosecond transient absorption spectroscopy reveals that different triplet states participate, namely, electron transfer between the N-aryl substituent and the fullerene.