Optical,Electrochemical, and Magnetic Properties of Pyrrole‐ and Thiophene‐Bridged 5,15‐Diazaporphyrin Dimers |
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| Authors: | Satoshi Omomo Yasuhisa Maruyama Prof. Dr. Ko Furukawa Dr. Taniyuki Furuyama Prof. Dr. Haruyuki Nakano Prof. Dr. Nagao Kobayashi Prof. Dr. Yoshihiro Matano |
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| Affiliation: | 1. Department of Fundamental Sciences, Graduate School of Science and Technology, Niigata University, Nishi‐ku, Niigata 950‐2181 (Japan);2. Department of Chemistry, Faculty of Science, Niigata University, Nishi‐ku, Niigata 950‐2181 (Japan), Fax: (+81)?25‐262‐7734;3. Center for Instrumental Analysis, Institute for Research Promotion, Niigata University, Nishi‐ku, Niigata 950‐2181 (Japan);4. Department of Chemistry, Graduate School of Science, Tohoku University, Aoba‐ku, Sendai 980‐8578 (Japan);5. Department of Chemistry, Graduate School of Sciences, Kyushu University, Fukuoka 812‐8581 (Japan) |
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| Abstract: | The first examples of pyrrole‐ and thiophene‐bridged 5,15‐diazaporphyrin (DAP) dimers are prepared through Stille coupling reactions of nickel(II) and copper(II) complexes of 3‐bromo‐10,20‐dimesityl‐5,15‐diazaporphyrin (mesityl=2,4,6‐trimethylphenyl) with the respective 2,5‐bis(tributylstannyl)heteroles. The effects of the heterole spacers and meso nitrogen atoms on the optical, electrochemical, and magnetic properties of the DAP dimers are investigated by UV/Vis absorption spectroscopy, density functional theory calculations, magnetic circular dichroism spectroscopy, cyclic voltammetry, and EPR spectroscopy. The heterole spacers are found to have a significant impact on the electronic transitions over the entire π‐system. In particular, the pyrrole‐bridged DAP dimers exhibit high light‐harvesting potential in the low‐energy visible/near‐infrared region owing to the intrinsic charge‐transfer character of the lowest excitation. |
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| Keywords: | diazaporphyrins EPR spectroscopy macrocyclic compounds porphyrinoids transition metals |
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