Highly Oxidized States of Phthalocyaninato Terbium(III) Multiple-Decker Complexes Showing Structural Deformations,Biradical Properties and Decreases in Magnetic Anisotropy |
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| Authors: | Dr. Yoji Horii Dr. Marko Damjanović Dr. M. R. Ajayakumar Prof. Dr. Keiichi Katoh Prof. Dr. Yasutaka Kitagawa Prof. Dr. Liviu Chibotaru Dr. Liviu Ungur Prof. Dr. Marta Mas-Torrent Prof. Dr. Wolfgang Wernsdorfer Prof. Dr. Brian K. Breedlove Prof. Dr. Markus Enders Prof. Dr. Jaume Veciana Prof. Dr. Masahiro Yamashita |
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| Affiliation: | 1. Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba Aoba-ku, Sendai, Miyagi, 980-8578 Japan;2. Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany;3. Department of Molecular Nanoscience and Organic Materials, Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC)/CIBER-BBN, 08193 Bellaterra, Spain;4. Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-8531 Japan;5. Theory of Nanomaterials Group, Katholieke Universiteit Leuven, 3001 Leuven, Belgium;6. Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore, Singapore;7. Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany |
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| Abstract: | Presented here is a comprehensive study of highly oxidized multiple-decker complexes composed of TbIII and CdII ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy groups. From X-ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl-shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species. From paramagnetic 1H NMR studies on the resulting series of triple, quadruple and quintuple-decker complexes, ligand oxidation leads to a decrease in the magnetic anisotropy, as predicted from theoretical calculations. Unusual paramagnetic shifts were observed in the spectra of the +2e charged quadruple and quintuple-decker complexes, indicating that those two species are actually unexpected triplet biradicals. Magnetic measurements revealed that the series of complexes show single-molecule magnet properties, which are controlled by the multi-step redox induced structural changes. |
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| Keywords: | biradical crystal engineering magnetic anisotropy NMR redox |
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