Spiropentadiene
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| Names | |
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| IUPAC name
Spiro[2.2]penta-1,4-diene
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| Other names
Bowtiediene; Spiropenta-1,4-diene
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| Identifiers | |
1727-65-7  |
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| Properties | |
| C5H4 | |
| Molar mass | 64.09 g·mol−1 |
| Vapor pressure | {{{value}}} |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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| Infobox references | |
Spiropentadiene, or bowtiediene, is a hydrocarbon with formula C5H4. The simplest spiro-connected cycloalkene, it is very unstable—decomposing even below −100 °C—due to its high bond strain and does not occur in nature. Its synthesis was reported in 1991.[1][2]
Synthesis
Spiropentadiene was synthesised from bistrimethylsilylpropynone 1 by reaction with p-toluenesulfonylhydrazide to tosylhydrazone 2 followed by treatment with sodium cyanoborohydride to allene 3 and followed by two successive reactions with chlorocarbene generated from methyllithium and dichloromethane to spiro compound 5. Spiropentadiene was trapped in a liquid nitrogen trap after reaction with TBAF in a double elimination reaction.
Derivatives
The derivative dichlorospiropentadiene has been reported.[3] An all-silicon derivative (Si5 frame, (tBuMe2Si)3Si side groups) is also known.[4] In contrast to the carbon parent this compound is stable with a melting point of 216 to 218 °C. The angle between the two rings as measured by X-ray single-crystal analysis is 78°.
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Elusive bowtie pinned down - synthesis of spiropentadiene, a carbonaceous compound nicknamed bowtiediene because it is shaped like a bowtie, Science News, July 13, 1991.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
