TY - JOUR
T1 - Photoinduced intramolecular electron-transfer processes in [60]fullerene and N,N-bis(biphenyl)aniline molecular systems in solutions
AU - Sandanayaka, Atula S.D.
AU - Ikeshita, Kei Ichiro
AU - Rajkumar, G. Abraham
AU - Furusho, Yoshio
AU - Araki, Yasuyuki
AU - Takata, Toshikazu
AU - Ito, Osamu
PY - 2005/9/15
Y1 - 2005/9/15
N2 - Photoinduced intramolecular charge-separation and charge-recombination processes in covalently connected C60-(spacer)-bis(biphenyl)aniline (C60-sp-BBA) and C60-((spacer)-bis(biphenyl)aniline) 2 (C60-(sp-BBA)2) have been studied by time-resolved fluorescence and transient absorption methods. Since a flexible alkylthioacetoamide chain was employed as the spacer, the folded structures in which the BBA moiety approaches the G60 moiety were obtained as optimized structures by molecular orbital calculations. The observed low fluorescence intensity and the short fluorescence lifetime of the C60 moiety of these molecular systems indicated that charge separation takes place via the excited singlet state of the G60 moiety in a quite fast rate and high efficiency even in the nonpolar solvent toluene, which was a quite new observation compared with reported dyads with different spacers. From the absorption bands at 880 and 1000 nm in the nanosecond transient absorption spectra, generations of C60•--sp-BBA •+ and C60•--(sp-BBA •+)(sp-BBA) were confirmed. The rates of charge separation and charge recombination for C60-(sp-BBA)2 are faster than those for C60-sp-BBA, suggesting that one of the BBA moieties approaches the C60 moiety by pushing another BBA moiety because of the flexible spacers.
AB - Photoinduced intramolecular charge-separation and charge-recombination processes in covalently connected C60-(spacer)-bis(biphenyl)aniline (C60-sp-BBA) and C60-((spacer)-bis(biphenyl)aniline) 2 (C60-(sp-BBA)2) have been studied by time-resolved fluorescence and transient absorption methods. Since a flexible alkylthioacetoamide chain was employed as the spacer, the folded structures in which the BBA moiety approaches the G60 moiety were obtained as optimized structures by molecular orbital calculations. The observed low fluorescence intensity and the short fluorescence lifetime of the C60 moiety of these molecular systems indicated that charge separation takes place via the excited singlet state of the G60 moiety in a quite fast rate and high efficiency even in the nonpolar solvent toluene, which was a quite new observation compared with reported dyads with different spacers. From the absorption bands at 880 and 1000 nm in the nanosecond transient absorption spectra, generations of C60•--sp-BBA •+ and C60•--(sp-BBA •+)(sp-BBA) were confirmed. The rates of charge separation and charge recombination for C60-(sp-BBA)2 are faster than those for C60-sp-BBA, suggesting that one of the BBA moieties approaches the C60 moiety by pushing another BBA moiety because of the flexible spacers.
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U2 - 10.1021/jp052063f
DO - 10.1021/jp052063f
M3 - Article
C2 - 16834194
AN - SCOPUS:25444520316
VL - 109
SP - 8088
EP - 8095
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 36
ER -