2000 Fiscal Year Final Research Report Summary
Design for Novel Organo Hypervalent Compounds
| Project/Area Number |
11304044
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| Research Category |
Grant-in-Aid for Scientific Research (A).
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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 | TOHO UNIVERSITY (2000)
Hiroshima University (1999) |
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Principal Investigator |
TAKAHASHI Masashi Toho University, Faculty of Science, Associate Professor, 理学部, 助教授 (30171523)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Yohsuke Hiroshima University, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (50158317)
AKIBA Kin-ya Toho University, Faculty of Science, Visiting Professor, 理学部, 客員教授 (20011538)
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| Project Period (FY) |
1999 – 2000
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| Keywords | hypervalent / pentacoordinate carbon species / pentacoordinate boron species / phophorane / phosphorus / arsenic / antimony / porphyrin |
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| Research Abstract |
Porphyrin complexes of group 15 : A equilibrium mixture of [(OEP)P(R)(OH)]^4Cl^-(10) and (OEP)PR(=O)(1)was obtained by the reaction of RPCl_2(R=Me, Et, Ph) and (OEP)H_2. Since the acidity of the OH group in 10 is high, 1 and 10 are selectively isolated by controlling pH for the solution of the mixture. The existence of P=O double bond in 1 is confirmed by the X-ray structural dctermination. (OEP) As (R)(=O)(14) is also obtained via [(OEP)As(R)(OH)]^<6+>X^- (13). 13 is the first arsenic porphyrin whose molecular structure is confirmed by X-ray crystallography. The acid-base equibrium between 14 and 13 is also observed. NMR indicates that the acidity of 13 is weaker than that of 10. The heterobimetallic μ-oxo porphyrins [(OEP)Al-O-E(OEP)(R)] (E=P, As) are derived by the reaction of [(OEP)Al(Me)] and the hydroxo porphyrins. The corresponding Al-Sb dinuclear porphyrin is obtained by a photo reaction. The formation of exciplex under the irradiation of light is suggested. ^<121>Sb Mossbauer
… More
spectra for Sb-TPP complexes indicate that the electronic state of Sb is strongly affected by the axial ligands.
Novel hypervalent pentacoordinate carbon and boron compounds : A stable pentacoordinate carbon compound [(MeO)_2C(DMA)]^+ having a 1,8-dimethoxyanthracene ((DMA)H) as a tridentate ligand is firstly isolated. The X-ray analysis definitely indicates the existence of O-C-O hypervalent bond and the density function theory (DFT) calculation also indicates the bonding interaction between C-O bond. The hypervalent pentacoordinate boron compound [(CAT)B(DMA)] (CAT=catecolate anion) is also prepared and fully specificated using an X-ray determination, ^<11>B NMR and a DFT calculation. Employing the van Koten type ligand as a flexible ligand, the second example of hypervalent carbon contpound is obtained and characterized.
anti-apicophilic phosphoranes : The anti-apicophilic spirophosphoranes having two Martin ligands (2 : O-cis) are obtained as kinetic products. 2 is highly nucleophilic compared to the apicophilic isomer (O-trans). The acidity of α-proton is high for 2, and by the reaction of its anion and benzaldehyde a hexacoordinate compound, being the intermediate species for Wittig reaction, is derived. No such a product is obtained for apicophilic isomer. Less
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