1997 Fiscal Year Final Research Report Summary
Studies on Synthesis and Properties of Model Molecules for Fullerene and the Related Compounds
| Project/Area Number |
08640683
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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 University |
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Principal Investigator |
KAWASE Takeshi Osaka University, Graduate School of Science, Associate Professor, 大学院・理学研究科, 助教授 (10201443)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Arylacetylenes / Conjugated system on a curvature / Fullerene / Polynucleocyclophane / Highly Strained Molecules / Supramolecular Chemistry |
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| Research Abstract |
Although the pi-orbitals of carbocyclic conjugated systems (annulenes) are oriented usually vertical to the plane of the ring, the pi-orbitals of the conjugated system on a curvature are aligned horizontally on a rigid surface and formed a belt-shaped conjugaed system. The discovery and large-scale synthesis of fullerenes have aroused interdisciplinary interest in these belt-shaped conjugated system. In this context, the synthesis of several model compounds, such as [n] cyclo-carbons, cyclacene, cyclic oligophenylene, and others have been attempted. These molecules are of interest not only from the synthetic and theoretical points of view but also as host molecules having a rigid vavity lined with a conjugated pi-system. Another class of belt-shaped molecules with a conjugated system are the cyclic oligomers of phenylacetylene linked at the para position, namely cyclic [n] paraphenylacetylene, [n] CPPA.We successfully synthesized [6] and [8] CPPAs from the corresponding [2.n] paracyclophanepolyenes through bromination-dehydrobromination reaction as relatively stable compounds. And the successive studies yielded the following results ;
(1)A good single crystal of [8] CPPA for X-ray analysis was collected from a cold toluene solution. The crystallographic analysis revealed that [8] CPPA has a slightly distorted cylindrical structure with 18.3* long axis and 16.5* short axis and four toluene molecules are included in the large cavity.
(2) Highly strained [2.2.2.2] and [2.2.2] Metacyclophane-poly-ynes could be also synthesized using same approach, and their physical properties and molecular structures were discussed.
(3) An efficient synthesis of macrocyclic cyclophanepolyenes as precursors for CPPAs has been achieved usin low-valent titanium reagent in toluene-DME solvent systems. [7] CPPA and other strained cyclic systems can be prepared from th method.
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Research Products
(6 results)
