Photoinduced Electron Transfer in an Amine–Corrole–Perylene Bisimide Assembly: Charge Separation over Terminal Components Favoured by Solvent Polarity

Authors

  • Dr. Roman Voloshchuk,

    1. Institute of Organic Chemistry of the Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)
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  • Prof. Dr. Daniel T. Gryko,

    Corresponding author
    1. Institute of Organic Chemistry of the Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)
    2. Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)
    • Institute of Organic Chemistry of the Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw (Poland)
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  • Dr. Maciej Chotkowski,

    1. Department of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw (Poland)
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  • Adina I. Ciuciu,

    1. Istituto per la Sintesi Organica e Fotoreattivitá (ISOF), CNR, Via P. Gobetti 101, 40129 Bologna (Italy)
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  • Dr. Lucia Flamigni

    Corresponding author
    1. Istituto per la Sintesi Organica e Fotoreattivitá (ISOF), CNR, Via P. Gobetti 101, 40129 Bologna (Italy)
    • Istituto per la Sintesi Organica e Fotoreattivitá (ISOF), CNR, Via P. Gobetti 101, 40129 Bologna (Italy)
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Abstract

An assembly has been synthesised that consists of four units: a meso-substituted corrole (C3), perylene bisimide (PI), and two electron-rich triphenylamine (DPA) units. PI is connected through a 1,4-phenylene bridge to C3, whereas the two DPA units are linked to C3 through a diphenyl ether linkage, which is used for the first time to connect the various moieties. Various synthetic strategies were elaborated, and the chosen one afforded the final system in six steps in an overall yield of 6 %. The resulting assembly, made of three different units, was named a “triad”. Excitation of the corrole (C3) or perylene bisimide (PI) units led to the charge-separated state DPA-C3+-PI with a rate k>1011 s−1 in benzonitrile and dichloromethane (CH2Cl2) or with k of the order of 1010 s−1 in toluene. The latter charge-separated state decayed to the ground state with a rate k=1.8×109 s−1 in toluene. In the polar solvents benzonitrile and dichloromethane, recombination to the ground state competes with a charge shift to form the distal charge-separated state, DPA+-C3-PI, the formation of which occurs with a yield of 50 %. Recombination to the ground state of DPA+-C3-PI occurs with a rate k=5×107 s−1 in CH2Cl2 and k=2×107 s−1 in benzonitrile.

Abstract

Barwnik funkcjonalny składający się z czterech podjednostek: mezo-podstawionego korolu, perylenobisimidu oraz dwóch trifenyloamin został zsyntetyzowany i poddany badaniom spektroskopowym i fotofizycznym. Analiza różnych strategii doprowadziła do opracowania efektywnej, sześcioetapowej syntezy finalnego układu wielochromoforowego. Wykazano, że wzbudzenie korolu lub perylenobisimidu prowadzi do wygenerowania stanu o rozdzielonych ładunkach DPA-C3+-PI, o czasie życia k=1.8×109s−1 w toluenie. W rozpuszczalnikach polarnych rekombinacja do stanu podstawowego efektywnie współzawodniczy z utworzeniem drugiego stanu o rozdzielonych ładunkach DPA+-C3-PI, podczas gdy w rozpuszczalnikach polarnych ten drugi proces nie jest obserwowany.

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