Volume 27, Issue 12 p. 4053-4063
Full Paper

A Light-Harvesting/Charge-Separation Model with Energy Gradient Made of Assemblies of meta-Pyridyl Zinc Porphyrins

Prof. Joe Otsuki

Corresponding Author

Prof. Joe Otsuki

Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8308 Japan

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Takumi Okumura

Takumi Okumura

Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8308 Japan

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Dr. Kosuke Sugawa

Dr. Kosuke Sugawa

Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8308 Japan

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Dr. Shin-ichiro Kawano

Dr. Shin-ichiro Kawano

Department of Chemistry, Graduate School of Science, Nagoya University, Furocho, Chikusa-ku, Nagoya, 464-8602 Japan

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Prof. Kentaro Tanaka

Prof. Kentaro Tanaka

Department of Chemistry, Graduate School of Science, Nagoya University, Furocho, Chikusa-ku, Nagoya, 464-8602 Japan

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Dr. Takehiro Hirao

Dr. Takehiro Hirao

Department of Chemistry, Graduate School of Advanced, Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan

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Prof. Takeharu Haino

Prof. Takeharu Haino

Department of Chemistry, Graduate School of Advanced, Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan

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Yu Jin Lee

Yu Jin Lee

Spectroscopy Laboratory for Functional π-Electronic Systems, and Department of Chemistry, Yonsei University, Seoul, 03722 South Korea

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Seongsoo Kang

Seongsoo Kang

Spectroscopy Laboratory for Functional π-Electronic Systems, and Department of Chemistry, Yonsei University, Seoul, 03722 South Korea

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Prof. Dongho Kim

Prof. Dongho Kim

Spectroscopy Laboratory for Functional π-Electronic Systems, and Department of Chemistry, Yonsei University, Seoul, 03722 South Korea

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First published: 29 October 2020
Citations: 1

Graphical Abstract

It′s a trimer! Zinc meso-(meta-pyridyl)porphyrin forms a trimer in solution over wide ranges of temperature and concentration. Incorporation of a directly linked porphyrin–ferrocene dyad with the same self-assembly motif led to a rare example of a light-harvesting/charge-separation system in which an energy gradient is incorporated and reductive quenching takes place.

Abstract

Self-assembly of porphyrins is a fascinating topic, not only for mimicking chlorophyll assemblies in photosynthetic organisms, but also for the potential of creating molecular-level devices. Herein, zinc porphyrin derivatives bearing a meta-pyridyl group at the meso position were prepared and their assemblies studied in chloroform. Among the porphyrins studied, one with a carbamoylpyridyl moiety gave a distinct 1H NMR spectrum in CDCl3, which allowed the supramolecular structure in solution to be probed in detail. Ring-current-induced chemical-shift changes in the 1H NMR spectrum, together with vapor-pressure osmometry and diffusion-ordered NMR spectroscopy, among other evidence, suggested that the porphyrin molecules form a trimer with a triangular cone structure. Incorporation of a directly linked porphyrin–ferrocene dyad with the same assembling properties in the assemblies led to a rare example of a light-harvesting/charge-separation system in which an energy gradient is incorporated and reductive quenching occurs.

Conflict of interest

The authors declare no conflict of interest.