Cyclohexanol

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Cyclohexanol[1]
Skeletal formula Ball-and-stick model
Identifiers
CAS number 108-93-0 YesY
PubChem 7966
ChemSpider 7678 YesY
EC-number 203-630-6
DrugBank DB03703
KEGG C00854 YesY
ChEBI CHEBI:18099 YesY
ChEMBL CHEMBL32010 YesY
RTECS number GV7875000
Jmol-3D images Image 1
Properties
Molecular formula C6H12O
Molar mass 100.158 g/mol
Appearance Colorless, viscous liquid.
Hygroscopic
Odor camphor-like
Density 0.9624 g/mL, liquid
Melting point 25.93 °C (78.67 °F; 299.08 K)
Boiling point 161.84 °C (323.31 °F; 434.99 K)
Solubility in water 3.60 g/100 mL (20 °C)
4.3 g/100 mL (30 °C)
Solubility soluble in ethanol, ethyl ether acetone, chloroform
miscible with ethyl acetate, linseed oil, benzene
kH 4.40 x 10-6 atm-cu m/mol
Acidity (pKa) 16
Refractive index (nD) 1.4641
Viscosity 41.07 mPa·s (30 °C)
Hazards
MSDS MSDS for cyclohexanol
R-phrases R20 R22 R37 R38
S-phrases S24 S25
Main hazards Flammable, skin irritant
Reacts violently with oxidizing agents
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 67 °C (153 °F; 340 K)
Explosive limits 2.7-12%
LD50 2.06 g/kg (oral, rat)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Cyclohexanol is the organic compound with the formula (CH2)5CHOH. The molecule is related to cyclohexane ring by replacement of one hydrogen atom by a hydroxyl group.[2] This compound exists as a deliquescent colorless solid, which, when very pure, melts near room temperature. Billions of kilograms are produced annually, mainly as a precursor to nylon.[3]

Production[edit]

Cyclohexanol is produced by the oxidation of cyclohexane in air, typically using cobalt catalysts:[3]

C6H12 + 1/2 O2 → C6H11OH

This process co-forms cyclohexanone, and this mixture ("KA oil" for ketone-alcohol oil) is the main feedstock for the production of adipic acid. The oxidation involves radicals and the intermediacy of the hydroperoxide C6H11O2H. Alternatively, cyclohexanol can be produced by the hydrogenation of phenol:

C6H5OH + 3 H2 → C6H11OH

This process can also be adjusted to favor the formation of cyclohexanone.

Basic reactions[edit]

Cyclohexanol undergoes the main reactions expected for a secondary alcohol. Oxidation gives cyclohexanone, which is converted on a large scale in industry to the oxime, a precursor to caprolactam. As a laboratory exercise, this oxidation can be effected with chromic acid. Esterification affords the commercially useful derivatives dicyclohexyladipate and dicyclohexylphthalate, which are used as plasticizers. Heating in the presence of acid catalysts converts cyclohexanol to cyclohexene.[3]

Structure[edit]

Cyclohexanol has at least two solid phases. One of them is a plastic crystal.

Applications[edit]

As indicated above, cyclohexanol is an important feedstock in the polymer industry, firstly as a precursor to nylons, but also to various plasticizers. Small amounts are used as a solvent.

Safety[edit]

Cyclohexanol is somewhat toxic: the TLV for the vapor for 8 h is 50 ppm.[3] The IDLH concentration is set at 400 ppm, based on studies on the acute oral toxicity in animals. [4] Few studies have been done on its carcinogenicity, but one study on rats found it to have co-carcinogenic effects.[5]

References[edit]

  1. ^ Merck Index, 11th Edition, 2731.
  2. ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5. 
  3. ^ a b c d Michael Tuttle Musser "Cyclohexanol and Cyclohexanone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
  4. ^ CDC - NIOSH Pocket Guide to Chemical Hazards
  5. ^ [1] Lucrecia Márquez-Rosado, Cristina Trejo-Solís 2, María del Pilar Cabrales-Romero, Evelia Arce-Popoca, Adolfo Sierra-Santoyo, Leticia Alemán-Lazarini, Samia Fatel-Fazenda, Claudia E. Carrasco-Legleu, Saúl Villa-Treviño, "Co-carcinogenic effect of cyclohexanol on the development of preneoplastic lesions in a rat hepatocarcinogenesis model", Molecular Carcinogenesis, Vol. 46, No. 7, Pages 524 - 533, March 2007.