Tetramethylbutane
| Tetramethylbutane | |
|---|---|
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| IUPAC name 2,2,3,3-Tetramethylbutane[1] | |
| Identifiers | |
| CAS number | 594-82-1  |
| PubChem | 11675 |
| ChemSpider | 11185  |
| EC number | 209-855-6 |
| UN number | 1325 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C8H18 |
| Molar mass | 114.23 g mol−1 |
| Appearance | White, opaque, waxy crystals |
| Odor | Odorless |
| Melting point | 98 to 104 °C; 208 to 219 °F; 371 to 377 K |
| Boiling point | 106.0 to 107.0 °C; 222.7 to 224.5 °F; 379.1 to 380.1 K |
| kH | 2.9 nmol Pa−1 kg−1 |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
−270.3 – −267.9 kJ mol−1 |
| Std enthalpy of combustion ΔcH |
−5.4526 – −5.4504 MJ mol−1 |
| Standard molar entropy S |
273.76 J K−1 mol−1 |
| Specific heat capacity, C | 232.2 J K−1 mol−1 (at 2.8 °C) |
| Hazards | |
| EU Index | 601-009-00-8 |
| EU classification |  F  Xn  N |
| R-phrases | R11, R38, R65, R67, R50/53 |
| S-phrases | (S2), S16, S29, S33 |
| Flash point | 4 °C; 39 °F; 277 K |
| Explosive limits | 1–?% |
| Related compounds | |
| Related alkanes | |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Tetramethylbutane, sometimes called hexamethylethane, is a hydrocarbon with formula C8H18 or (H3C-)3C-C(-CH3)3. It is the most heavily branched and most compact of the many octane isomers, the only one with a butane (C4) backbone. Because of its highly symmetrical structure, it has a very high melting point and a short liquid range.
The compound can be obtained by reaction of Grignard reagent tert-butylmagnesium bromide with ethyl bromide, or of ethylmagnesium bromide with tert-butyl bromide in the presence of manganese(II) ions.[2] This transformation is believed to go through the dimerization of two tert-butyl radicals, which are generated by decomposition of the organomanganese compounds generated in situ.
The full IUPAC name of the compound is 2,2,3,3-tetramethylbutane, but the numbers are superfluous in this case because there is no other possible arrangement of "tetramethylbutane".
References
- ↑ "Hexamethylethane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Information. Retrieved 11 March 2012.
- ↑ M. S. KHARASCH, J. W. HANCOCK, W. NUDENBERG, P. O. TAWNEY (1956). "Factors Influencing the Course and Mechanism of Grignard Reactions. XXII. The Reaction of Grignard Reagents with Alkyl Halides and Ketones in the Presence of Manganous Salts". Journal of Organic Chemistry 21 (3): 322–327. doi:10.1021/jo01109a016.