2006 Fiscal Year Final Research Report Summary
Syntheses, Electronic Structures, and Intermolecular Interactions of Singlet Biradical Molecules
| Project/Area Number |
17550034
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Organic chemistry
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| Research Institution | Osaka Univeristy |
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Principal Investigator |
KUBO Takashi Osaka Univeristy, Graduate School of Science, Professor, 理学研究科, 教授 (60324745)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Singlet biradical / Phenalenyl / Intermolecular interaction / Electro-conductivity / Non-linear optics / Two photon absorption / Polarized reflection spectra / SQUID |
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| Research Abstract |
Some Kekule compounds such as quinoid hydrocarbons have relatively small HOMO-LUMO gaps and show extremely high chemical reactivity. The representative is p-quinodimethane that has been defined as a biradicaloid compound, which could be categorized as a delocalized singlet biradical. In order to isolate such a reactive closed-shell biradical and to investigate properties associated with the biradical character, we introduced spin-delocalization moieties to p-quinodimethane and 2,6-naphthoquinodimethane. Newly designed molecules were prepared by multistep syntheses, and were found to be stable even in air at room temperature. Biradical character of the compounds was estimated to be 30% and 50% by a CASSCF(2,2)/6-31G calculation, respectively. An X-ray crystallographic analysis revealed one-dimensional π-stacking chains with short π-π contacts (3.14-3.16 Å). Compressed pellets of the compounds exhibited semi-conductive behavior (σ_<RT>=〜10^<-5> S cm^<-1>1,E_a = 0.2-0.3 eV), and large bandwidths were achieved along the π-π stacking according to an EHMO band calculation. Polarized reflection spectra of the single crystals showed intense bands at near-IR regions in the π-π stacking directions. The solid state bands are extraordinary lower in energy than the solution absorption bands. A strong intermolecular spin-spin interaction as well as an intramolecular one would be responsible for the large bandwidths and the lower-energy shifts of the absorption bands.
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Research Products
(20 results)
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[Patent(Industrial Property Rights)] 二光子吸収材料2005
Inventor(s)
中野雅由, 久保孝史, 鎌田賢司, 大田浩二, 山口 兆, 中筋一弘, 森田 靖, 岸 亮平, 清水章弘
Industrial Property Rights Holder
大阪大学及び, 独立行政法人産業技術総合研究所
Industrial Property Number
特許公開2007-77091
Filing Date
2005-09-15
Description
「研究成果報告書概要(和文)」より
