Cyclohexane
Identifiers
CAS number	[110-82-7]
SMILES	C1CCCCC1
Properties
Molecular formula	C6H12
Molar mass	84. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 16 g/mol
Density	0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 779 g/ml, liquid
Melting point	6. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 5 °C, 280 K, 44 °F
Boiling point	80. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 74 °C, 354 K, 177 °F
Solubility in water	Immiscible
Viscosity	1. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Viscosity is a measure of the resistance of a Fluid which is being deformed by either Shear stress or Extensional stress. 02 cP at 17 °C
Thermochemistry
Std enthalpy of formation ΔfHo298	-156 kJ/mol
Std enthalpy of combustion ΔcHo298	-3920 kJ/mol
Hazards
MSDS	External MSDS
EU classification	Flammable (F) Harmful (Xn) Dangerous for the environment (N) Severe eye irritant, may cause corneal clouding
NFPA 704	3 1 0
R-phrases	R11, R38, R65, R67, R50/53
S-phrases	(S2), S9, S16, S25, S33, S60, S61, S62
Flash point	-20 C
Related compounds
Related cycloalkanes	Cyclopentane Cycloheptane
Related compounds	Cyclohexene Benzene
Supplementary data page
Structure and properties	n, εr, etc. The poise (symbol P pwɑːz is the unit of dynamic Viscosity in the Centimetre gram second system of units. The standard enthalpy of formation or "standard heat of formation" of a compound is the change of Enthalpy that accompanies the formation of 1 mole of a The standard enthalpy of combustion is the Enthalpy change when one mole of a substance completely reacts with oxygen under standard thermodynamic conditions (although A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance This page provides supplementary chemical data on Cyclohexane Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air Cycloalkanes (also called naphthenes, especially if from Petroleum sources are types of Alkanes which have one or more rings of Carbon Atoms Cyclopentane is a highly Flammable alicyclic Hydrocarbon with Chemical formula 510 and CAS number 287-92-3 Cycloheptane is a Cycloalkane with the Molecular formula C 7 H 14 Cyclohexene is a colorless clear Liquid Cycloalkene with an intense aversive characteristic sharp smell reminiscent of an Oil refinery. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 This page provides supplementary chemical data on Cyclohexane This page provides supplementary chemical data on Cyclohexane The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium Measurement The relative static permittivity εr can be measured for static Electric fields as follows first the Capacitance of a test
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Cyclohexane is a cycloalkane with the molecular formula C₆H₁₂. This page provides supplementary chemical data on Cyclohexane This page provides supplementary chemical data on Cyclohexane Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly Cycloalkanes (also called naphthenes, especially if from Petroleum sources are types of Alkanes which have one or more rings of Carbon Atoms A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Cyclohexane is used as a nonpolar solvent for the chemical industry, and also as a raw material for the industrial production of adipic acid and caprolactam, both of which are intermediates used in the production of nylon. "Polar molecule" and "Non-polar" redirect here A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. Adipic acid ( IUPAC Systematic name: hexanedioic acid) is a di Carboxylic acid. Caprolactam is an Organic compound which is a Lactam of 6-aminohexanoic acid (ε-aminohexanoic acid Aminocaproic acid) Overview Nylon is a Thermoplastic silky material first used commercially in a nylon- Bristled Toothbrush (1938 followed more famously by On an industrial scale, cyclohexane is produced by reacting benzene with hydrogen. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Due to its unique chemical and conformational properties, cyclohexane is also used in labs in analysis and as a standard.

Chemical conformation

Main article: cyclohexane conformation

The 6 vertexed ring does not conform to the shape of a perfect hexagon. Cyclohexane conformation is a much studied topic in Organic chemistry because of the complex interrelationship between the different conformers of Cyclohexane Regular hexagon The internal Angles of a regular hexagon (one where all sides and all angles are equal are all 120 ° and the hexagon has 720 degrees The conformation of a flat 2D planar hexagon has considerable angle strain because its bonds are not 109. 5 degrees; the torsional strain would also be considerable due to all eclipsed bonds. The term torsion may refer the following In geometry Torsion of curves Torsion tensor in differential geometry Therefore, to reduce torsional strain, cyclohexane adopts a three-dimensional structure known as the chair conformation. Alkane stereochemistry concerns the Stereochemistry of linear Alkanes and the linear alkane Conformers The existence of more than one conformation is due Cyclohexane conformation is a much studied topic in Organic chemistry because of the complex interrelationship between the different conformers of Cyclohexane The new conformation puts the carbons at an angle of 109. 5°. Half of the hydrogens are in the plane of the ring (equatorial) while the other half are perpendicular to the plane (axial). This conformation allows for the most stable structure of cyclohexane. Another conformation of cyclohexane exists, known as boat conformation, but it interconverts to the slightly more stable chair formation. Cyclohexane conformation is a much studied topic in Organic chemistry because of the complex interrelationship between the different conformers of Cyclohexane If cyclohexane is mono-substituted with a large substituent, then the substituent will most likely be found attached in an equatorial position, as this is the slightly more stable conformation. In Organic chemistry, a substituent is an atom or group of atoms substituted in place of a Hydrogen atom on the Parent chain of a Hydrocarbon

Cyclohexane has the lowest angle and torsional strain of all the cycloalkanes, as a result cyclohexane has been deemed a 0 in total ring strain, a combination of angle and torsional strain. This also makes cyclohexane the most stable of the cycloalkanes and therefore will produce the least amount of heat when burned compared to the other cycloalkanes.

A cyclohexane molecule in chair conformation. Hydrogen atoms in axial positions are shown in red, while those in equatorial positions are in blue.

Reactions with cyclohexane

Pure cyclohexane in itself is rather unreactive, being a non-polar, hydrophobic hydrocarbon. In Chemistry, hydrophobicity (from the combining form of water in Attic Greek hydro- and for fear phobos) refers to the physical property of It can react with very strong acids such as the superacid system HF + SbF₅ which will cause forced protonation and "hydrocarbon cracking". A superacid is an Acid with an Acidity greater than that of 100% Sulfuric acid, which has a Hammett acidity function ( H 0 Fluoroantimonic acid HSbF6 is a mixture of Hydrogen fluoride and Antimony pentafluoride in various ratios Substituted cyclohexanes, however, may be reactive under a variety of conditions, many of which are important to organic chemistry. Cyclohexane is highly flammable.

Cyclohexane derivatives

The specific arrangement of functional groups in cyclohexane derivatives, and indeed in most cycloalkane molecules, is extremely important in chemical reactions, especially reactions involving nucleophiles. In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions In Chemistry, a nucleophile (literally nucleus lover as in nucleus and phile) is a Reagent that forms a Chemical bond to Substituents on the ring must be in the axial formation to react with other molecules. Cyclohexane conformation is a much studied topic in Organic chemistry because of the complex interrelationship between the different conformers of Cyclohexane For example, the reaction of bromocyclohexane and a common nucleophile, a hydroxide anion (OH⁻), would result in cyclohexene:

C₆H₁₁Br + OH⁻ → C₆H₁₀ + H₂O + Br⁻

This reaction, commonly known as an elimination reaction or dehalogenation (specifically E2), requires that the bromine substituent be in the axial formation, opposing another axial H atom to react. In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen Cyclohexene is a colorless clear Liquid Cycloalkene with an intense aversive characteristic sharp smell reminiscent of an Oil refinery. An elimination reaction is a type of Organic reaction in which two Substituents are removed from a molecule in either a one or two-step mechanism. In Organic chemistry, a substituent is an atom or group of atoms substituted in place of a Hydrogen atom on the Parent chain of a Hydrocarbon Assuming that the bromocyclohexane was in the appropriate formation to react, the E2 reaction would commence as such:

1. The electron pair bond between the C-Br moves to the Br, forming Br⁻ and setting it free from cyclohexane
2. The nucleophile (-OH) gives an electron pair to the adjacent axial H, setting H free and bonding to it to create H₂O
3. The electron pair bond between the adjacent axial H moves to the bond between the two C-C making it C=C

Note: All three steps happen simultaneously, characteristic of all E2 reactions.

The reaction above will generate mostly E2 reactions and as a result the product will be mostly (~70%) cyclohexene. Cyclohexene is a colorless clear Liquid Cycloalkene with an intense aversive characteristic sharp smell reminiscent of an Oil refinery. However, the percentage varies with conditions, and generally, two different reactions (E2 and S_N2) compete. In organic and Inorganic chemistry, nucleophilic substitution is a fundamental class of Substitution reaction in which an "electron rich" In the above reaction, an S_N2 reaction would substitute the bromine for a hydroxyl (OH^-) group instead, but once again, the Br must be in axial to react. Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. Once the S_N2 substitution is complete, the newly substituted OH group would flip back to the more stable equatorial position quickly (~1 millisecond).

Uses

Commercially most of cyclohexane produced is converted into cyclohexanone-cyclohexanol mixture (or "KA oil") by catalytic oxidation. Cyclohexanone is a six-carbon cyclic molecule with a Ketone functional group Cyclohexanol is a secondary alcohol, formula C 6 H 11 OH, consisting of a Cyclohexane ring with one Hydrogen KA oil is then used as a raw material for adipic acid and caprolactam. Adipic acid ( IUPAC Systematic name: hexanedioic acid) is a di Carboxylic acid. Caprolactam is an Organic compound which is a Lactam of 6-aminohexanoic acid (ε-aminohexanoic acid Aminocaproic acid) Practically, if the cyclohexanol content of KA oil is higher than cyclohexanone, it is more likely(economical) to be converted into adipic acid, and the reverse case, caprolactam production is more likely. Such ratio in KA oil can be controlled by selecting suitable oxidation catalyst. Some of cyclohexane is used as an organic solvent.

Cyclohexane in research

Although much is already known about this cyclic hydrocarbon, research is still being done on cyclohexane and benzene mixtures and solid phase cyclohexane to determine hydrogen yields of the mix when irradiated at −195 °C. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6

History

Unlike compounds like benzene, cyclohexane cannot easily be obtained from natural resources such as coal. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Towards the end of the nineteenth century early chemical investigators had to depend on organic synthesis. It took them 30 years to flesh out the details^[1]. In 1867 Marcellin Berthelot reduced benzene with hydroiodic acid at elevated temperatures. Marcellin (or Marcelin Pierre Eugène Berthelot ( October 25, 1827 - March 18, 1907) was a French Chemist and Politician Organic reductions or organic oxidations or organic redox reactions are Redox reactions that take place with Organic compounds In Organic Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 Hydrogen iodide (HI is a Diatomic molecule. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a Strong acid. He incorrectly identified the reaction product as n-hexane not only because of the convenient match in boiling point (69°C) but also because he did not believe benzene was a cyclic molecule (like his contemporary August Kekule) but rather some sort of association of acetylene. Hexane is an Alkane Hydrocarbon with the Chemical formula CH3(CH24CH3 or C6H14 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Friedrich August Kekule von Stradonitz (also August Kekulé) (7 September 1829 &ndash 13 July 1896 was a German organic chemist. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes In 1870 one of his sceptics Adolf von Baeyer repeated the reaction and pronounced the same reaction product hexahydrobenzene and in 1890 Vladimir Markovnikov believed he was able to distill the same compound from Caucasus petroleum calling his concoction hexanaphtene

In 1894 Baeyer synthesized cyclohexane starting with a Dieckmann condensation of pimelic acid followed by multiple reductions:

and in the same year E. Johann Friedrich Wilhelm Adolf von Baeyer (ˈbaɪɐ October 31, 1835 - August 20, 1917) was a German chemist who Vladimir Vasilyevich Markovnikov (Марковников Владимир Васильевич also spelled as Markownikoff ( December 22, 1838 in Petroleum ( L petroleum, from Greek πετρέλαιον, lit The Dieckmann condensation is the Intramolecular Chemical reaction of di Esters with base to give β-ketoesters Pimelic acid is the Organic compound with the formula HO2C(CH25CO2H Haworth and W. H. Perkin Jr. (1860 - 1929) did the same in a Wurtz reaction of 1,6-dibromohexane. The Wurtz reaction, named after Charles-Adolphe Wurtz, is a Coupling reaction in Organic chemistry, Organometallic chemistry and recently inorganic

Surprisingly their cyclohexanes boiled higher by 10°C than either hexahydrobenzene or hexanaphtene but this riddle was solved in 1895 by Markovnikov, N. M. Kishner and Nikolay Zelinsky when they re-diagnosed hexahydrobenzene and hexanaphtene as methylcyclopentane, the result of an unexpected rearrangement reaction. Nikolay Dimitrievich Zelinsky ( Зелинский Николай Дмитриевич in Russian) ( February 6 n Alkyl cycloalkanes are Chemical compounds with an Alkyl group with a single ring of Carbons to which Hydrogens are attached according to the formula A rearrangement reaction is a broad class of Organic reactions where the carbon skeleton of a Molecule is rearranged to give a Structural isomer of the original

See also

• The Flixborough disaster, a major industrial accident caused by an explosion of cyclohexane. The Flixborough disaster was an Explosion at a chemical plant close to the village of Flixborough (near Scunthorpe) North Lincolnshire,
• Hexane

External links

• International Chemical Safety Card 0242
• National Pollutant Inventory - Cyclohexane fact sheet
• NIOSH Pocket Guide to Chemical Hazards
• Cyclohexane@3Dchem
• NLM Hazardous Substances Databank – Cyclohexane

References

1. ^ The curiously intertwined histories of benzene and cyclohexane E. Hexane is an Alkane Hydrocarbon with the Chemical formula CH3(CH24CH3 or C6H14 W. Warnhoff J. Chem. Ed. , 1996 494