Mimicking Photosynthetic Antenna-Reaction-Center Complexes with a (Boron Dipyrromethene)3–Porphyrin–C60 Pentad

Authors

  • Dr. Jian-Yong Liu,

    1. Department of Chemistry and Center of Novel Functional Molecules, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong (China), Fax: (+852) 2603-5057
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    • These authors contributed equally to this work.

  • Dr. Mohamed E. El-Khouly,

    1. Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan), Fax: (+81) 6-6879-7370668-797-370
    2. Department of Chemistry, Faculty of Science, Kafr El-Sheikh University, Kafr El-Sheikh 33516 (Egypt)
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    • These authors contributed equally to this work.

  • Prof. Shunichi Fukuzumi,

    Corresponding author
    1. Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan), Fax: (+81) 6-6879-7370668-797-370
    2. Department of Bioinspired Science, Ewha Womans University, Seoul 120-750 (Korea)
    • Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan), Fax: (+81) 6-6879-7370668-797-370
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  • Prof. Dennis K. P. Ng

    Corresponding author
    1. Department of Chemistry and Center of Novel Functional Molecules, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong (China), Fax: (+852) 2603-5057
    • Department of Chemistry and Center of Novel Functional Molecules, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong (China), Fax: (+852) 2603-5057
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Abstract

A highly efficient functional mimic of the photosynthetic antenna-reaction-center complexes has been designed and synthesized. The model contains a zinc(II) porphyrin (ZnP) core, which is connected to three boron dipyrromethene (BDP) units by click chemistry, and to a C60 moiety using the Prato procedure. The compound has been characterized using various spectroscopic methods. The intramolecular photoinduced processes of this pentad have also been studied in detail with steady-state and time-resolved absorption and emission spectroscopic methods, both in polar benzonitrile and nonpolar toluene. The BDP units serve as the antennae, which upon excitation undergo singlet–singlet energy transfer to the porphyrin core. This is then followed by an efficient electron transfer to the C60 moiety, resulting in the formation of the singlet charge-separated state (BDP)3–ZnP.+–C60., which has a lifetime of 476 and 1000 ps in benzonitrile and toluene, respectively. Interestingly, a slow charge-recombination process (equation image=2.6×106 s−1) and a long-lived triplet charge-separated state (equation image=385 ns) were detected in polar benzonitrile by nanosecond transient measurements.

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