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| Names | |||
|---|---|---|---|
| Preferred IUPAC name Methylcyclopentane | |||
| Identifiers | |||
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3D model (JSmol) | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider |
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| ECHA InfoCard | 100.002.277 | ||
| EC Number |
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| UNII | |||
| UN number | 2298 | ||
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| Properties | |||
| C6H12 | |||
| Molar mass | 84.162 g·mol−1 | ||
| Appearance | Colorless liquid | ||
| Density | 0.749 g/cm3[1] | ||
| Melting point | −142.4 °C (−224.3 °F; 130.8 K)[1] | ||
| Boiling point | 71.8 °C (161.2 °F; 344.9 K)[1] | ||
| Insoluble | |||
| −70.17·10−6 cm3/mol | |||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards | flammable | ||
| Flash point | −4 °C (25 °F; 269 K) | ||
| 260 °C (500 °F; 533 K) | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Methylcyclopentane is anorganic compound with thechemical formula CH3C5H9. It is a colourless, flammable liquid with a faint odor. It is a component of thenaphthene fraction of petroleum usually obtained as a mixture withcyclohexane. It is mainly converted in naphthenereformers tobenzene.[2]
As of early 1990s, it was present in American[3] and European[4]gasoline in small amounts, and by 2011 its share in US gasoline varied between 1 and 3%.[5] It has a research octane number of 103 and motor octane number of 95.[6]
The C6 core of methylcyclopentane is not perfectly planar and canpucker to alleviate stress in its structure.[7]
Methylcyclopentane was first synthesized in 1888 byPaul Caspar Freer [Wikidata] andW. H. Perkin Jr. by aWurtz reaction ofsodium and 1,5-dibromohexane.[8] They named itmethylpentamethylene since the modern nomenclature wasn't developed until 1892Geneva Rules.
In 1895,Nikolai Kischner discovered that methylcyclopentane was the reaction product of hydrogenation ofbenzene usinghydriodic acid. Prior to that, several chemists (such asMarcellin Berthelot in 1867,[9][10] andAdolf von Baeyer in 1870[11]) had tried and failed to synthesizecyclohexane using this method.
En effet, la benzine, chauffée à 280° pendant 24 heures avec 80 fois son poids d'une solution aqueuse saturée à froid d'acide iodhydrique, se change à peu près entièrement en hydrure d'hexylène, C12H14, en fixant 4 fois son volume d'hydrogène: C12H6 + 4H2 = C12H14 … Le nouveau carbure formé par la benzine est un corps unique et défini: il bout à 69°, et offre toutes les propriétés et la composition de l'hydrure d'hexylène extrait des pétroles.[In effect, benzene, heated to 280° for 24 hours with 80 times its weight of an aqueous solution of cold saturated hydroiodic acid, is changed almost entirely into hydride of hexylene, C12H14, [Note: this formula for hexane (C6H14) is wrong because chemists at that time used the incorrect atomic mass for carbon.] by fixing [i.e., combining with] 4 times its volume of hydrogen: C12H6 + 4H2 = C12H14 The new carbon compound formed by benzene is a unique and well-defined substance: it boils at 69° and presents all the properties and the composition of hydride of hexylene extracted from oil.)]
Bei der Reduction mit Natriumamalgam oder Jodphosphonium addiren sich im höchsten Falle sechs Atome Wasserstoff, und es entstehen Abkömmlinge, die sich von einem Kohlenwasserstoff C6H12 ableiten. Dieser Kohlenwasserstoff ist aller Wahrscheinlichkeit nach ein geschlossener Ring, da seine Derivate, das Hexahydromesitylen und Hexahydromellithsäure, mit Leichtigkeit wieder in Benzolabkömmlinge übergeführt werden können.[During the reduction [of benzene] with sodium amalgam or phosphonium iodide, six atoms of hydrogen are added in the extreme case, and there arise derivatives, which derive from a hydrocarbon C6H12. This hydrocarbon is in all probability a closed ring, since its derivatives — hexahydromesitylene [1,3,5 - trimethyl cyclohexane] and hexahydromellithic acid [cyclohexane-1,2,3,4,5,6-hexacarboxylic acid] — can be converted with ease again into benzene derivatives.]
