TY - JOUR
T1 - Photonic Switching of Photoinduced Electron Transfer in a Dihydropyrene-Porphyrin-Fullerene Molecular Triad
AU - Liddell, Paul A.
AU - Kodis, Gerdenis
AU - Andréasson, Joakim
AU - De La Garza, Linda
AU - Bandyopadhyay, Subhajit
AU - Mitchell, Reginald H.
AU - Moore, Thomas
AU - Moore, Ana
AU - Gust, Devens
PY - 2004/4/21
Y1 - 2004/4/21
N2 - Photonic control of photoinduced electron transfer has been demonstrated in a dimethyldihydropyrene (DHP) porphyrin (P) fullerene (C60) molecular triad. In the DHP-P-C60 form of the triad, excitation of the porphyrin moiety is followed by photoinduced electron transfer to give a DHP-P.+-C60.- charge-separated state, which evolves by a charge shift reaction to DHP.+-P-60 .-. This final state has a lifetime of 2 μs and is formed in an overall yield of 94%. Visible (≥300 nm) irradiation of the triad leads to photoisomerization of the DHP moiety to the cyclophanediene (CPD). Excitation of the porphyrin moiety of CPD-P-C60 produces a short-lived (<10 ns) CPD-P.+-C60.- state, but charge shift to the CPD moiety does not occur, due to the relatively high oxidation potential of the CPD group. Long-lived charge separation is not observed. Irradiation of CPD-P-C60 with UV (254 nm) light converts the triad back to the DHP form. Thermal interconversion of the DHP and CPD forms is very slow, photochemical cycling is facile, and in the absence of oxygen, many cycles may be performed without substantial degradation. Thus, light is used to switch long-lived photoinduced charge separation on or off. The principles demonstrated by the triad may be useful for the design of molecule-based optoelectronic systems.
AB - Photonic control of photoinduced electron transfer has been demonstrated in a dimethyldihydropyrene (DHP) porphyrin (P) fullerene (C60) molecular triad. In the DHP-P-C60 form of the triad, excitation of the porphyrin moiety is followed by photoinduced electron transfer to give a DHP-P.+-C60.- charge-separated state, which evolves by a charge shift reaction to DHP.+-P-60 .-. This final state has a lifetime of 2 μs and is formed in an overall yield of 94%. Visible (≥300 nm) irradiation of the triad leads to photoisomerization of the DHP moiety to the cyclophanediene (CPD). Excitation of the porphyrin moiety of CPD-P-C60 produces a short-lived (<10 ns) CPD-P.+-C60.- state, but charge shift to the CPD moiety does not occur, due to the relatively high oxidation potential of the CPD group. Long-lived charge separation is not observed. Irradiation of CPD-P-C60 with UV (254 nm) light converts the triad back to the DHP form. Thermal interconversion of the DHP and CPD forms is very slow, photochemical cycling is facile, and in the absence of oxygen, many cycles may be performed without substantial degradation. Thus, light is used to switch long-lived photoinduced charge separation on or off. The principles demonstrated by the triad may be useful for the design of molecule-based optoelectronic systems.
UR - http://www.scopus.com/inward/record.url?scp=1942439825&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1942439825&partnerID=8YFLogxK
U2 - 10.1021/ja039800a
DO - 10.1021/ja039800a
M3 - Article
C2 - 15080684
AN - SCOPUS:1942439825
SN - 0002-7863
VL - 126
SP - 4803
EP - 4811
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 15
ER -