A Light-Harvesting/Charge-Separation Model with Energy Gradient Made of Assemblies of meta-Pyridyl Zinc Porphyrins |
| |
Authors: | Prof Joe Otsuki Takumi Okumura Dr Kosuke Sugawa Dr Shin-ichiro Kawano Prof Kentaro Tanaka Dr Takehiro Hirao Prof Takeharu Haino Yu Jin Lee Seongsoo Kang Prof Dongho Kim |
| |
Institution: | 1. Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8308 Japan;2. Department of Chemistry, Graduate School of Science, Nagoya University, Furocho, Chikusa-ku, Nagoya, 464-8602 Japan;3. Department of Chemistry, Graduate School of Advanced, Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8526 Japan;4. Spectroscopy Laboratory for Functional π-Electronic Systems, and Department of Chemistry, Yonsei University, Seoul, 03722 South Korea |
| |
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. |
| |
Keywords: | energy transfer porphyrinoids self-assembly structure elucidation zinc |
|
|