Hydrogen‐Bonding Effect on Spin‐Center Transfer of Tetrathiafulvalene‐Linked 6‐Oxophenalenoxyl Evaluated Using Temperature‐Dependent Cyclic Voltammetry and Theoretical Calculations |
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Authors: | Dr. Shinsuke Nishida Prof. Dr. Kozo Fukui Prof. Dr. Yasushi Morita |
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Affiliation: | 1. Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560‐0043 (Japan), Fax: (+81)?6‐6850‐5393 http://www.chem.sci.osaka‐u.ac.jp/lab/nakasuji/morita/index.html;2. Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 5 Sanban‐cho, Chiyoda‐ku, Tokyo 102‐0075 (Japan) |
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Abstract: | The stable tetrathiafulvalene (TTF)‐linked 6‐oxophenalenoxyl neutral radical exhibits a spin‐center transfer with a continuous color change in solution caused by an intramolecular electron transfer, which is dependent on solvent and temperature. Cyclic voltammetry measurements showed that addition of 2,2,2‐trifluoroethanol (TFE) to a benzonitrile solution of the neutral radical induces a redox potential shift that is favorable for the spin‐center transfer. Temperature‐dependent cyclic voltammetry of the neutral radical using a novel low‐temperature electrochemical cell demonstrated that the redox potentials change with decreasing temperature in a 199:1 CH2Cl2/TFE mixed solvent. Furthermore, theoretical calculation revealed that the energy levels of the frontier molecular orbitals involved in the spin‐center transfer are lowered by the hydrogen‐bonding interaction of TFE with the neutral radical. These results indicate that the hydrogen‐bonding effect is a key factor for the occurrence of the spin‐center transfer of TTF‐linked 6‐oxophenalenoxyl. |
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Keywords: | 6‐oxophenalenoxyl cyclic voltammetry electron transfer radicals tetrathiafulvalene |
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