1998 Fiscal Year Final Research Report Summary
Construction of Local Spin Ordering System through Polarons
| Project/Area Number |
09440237
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
SUGAWARA Tadashi The University of Tokyo, Graduate School of Arts and Sciences, Professor, 大学院・総合文化研究科, 教授 (50124219)
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| Project Period (FY) |
1997 – 1998
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| Keywords | nitronyl nitroxide / ploypyrrole / ESR / triplet / exchange interaction |
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| Research Abstract |
Construction of high spin molecules is an important target of research in molecular magnetism'. We have demonstrated a number of high spin polycarbenes based on the pi-topology. However there is a problem concerning the kinetic stability of high spin polycarbenes. The aim of this project is to prepare stable high spin molecules, replacing a siguma-spin and a pi-spin of carbenes with a local spin of the stable radical unit and a polaronic spin in the conjugated pi-system. As a target molecule we designed a polypyrrole carrying nitronyl nitroxide groups. A ferromagnetic coupling of the oligomers is originated from a space-sharing nature of the partial molecular orbitals belonging to the radical unit and the pyrrole unit. As an appropriate building block of such a high spin oligopyrrole, we prepared several pyrrole derivatives and found that N-(p-NN-phenyl)pyrrole affords a ground state triplet species upon one-electron oxidation. Furthermore, thienyl groups were introduced at the alpha-positions on both sides of the pyrrole ring as reactive sites. This monomer turned out to afford desired hybrid-oligomers under the oxidative condition. Magnetic and conductive properties of them will be investigated even after the research period of this project.
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