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Syntheses and Properties of (Nitronyl nitroxide)-substituted Tri-phenylamine ortho-Bridged by Two Oxygen and Sulfur Atoms |
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| Authors: | Naoki Yokoyama Nobuaki Tanaka Natsumi Fujimoto Dr. Rika Tanaka Prof. Dr. Shuichi Suzuki Prof. Daisuke Shiomi Prof. Dr. Kazunobu Sato Prof. Dr. Takeji Takui Prof. Dr. Masatoshi Kozaki Prof. Dr. Keiji Okada |
| Affiliation: | 1. Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585 Japan;2. X-ray Crystal Analysis Laboratory, Graduate School of Engineering, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585 Japan;3. Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531 Japan;4. Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, 558-8585 Japan Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Sumiyoshi-ku, Osaka, 558-8585 Japan K. O. Deceased. |
| Abstract: | A nitronyl nitroxide unit ( NN ) was linked with a triphenylamine-based condensed polycyclic skeleton DOTT to form a radical substituted donor NN - DOTT . X-ray crystal structure analysis demonstrated a flat bowl shape of the DOTT unit. EPR spectra showed the localization of electron spin on the NN unit. Chemical oxidation of the DOTT unit produced radical-substituted radical cation salts NN - DOTT + ⋅ SbF6− and NN - DOTT + ⋅ FeBr4− that are stable under ambient conditions. The magnetic behavior of NN - DOTT + ⋅ SbF6− is characterized by the strong intramolecular ferromagnetic interaction between NN and DOTT +. The X-ray structural analysis of NN - DOTT + ⋅ FeBr4− shows planar structure of DOTT and 1D mixed-stack column of NN-DOTT + and FeBr4−. Magnetic measurements established that NN - DOTT + ⋅ FeBr4− undergoes magnetic phase transition into a weak ferromagnet at 7 K. |
| Keywords: | cations heterocycles magnetic properties phase transitions radical ions |