Tertiary butyl alcohol structure, properties, risks and uses

3892
Robert Johnston

The tertiary butyl alcohol is an organic compound whose formula is (CH3)3COH or t-BuOH. It is the simplest tertiary alcohol of all. Depending on the ambient temperature, it appears as a colorless solid or liquid. The image below shows, for example, its colorless crystals.

This alcohol is not a substrate for the alcoholic dehydrogenase enzyme, nor for the peroxidase activity of catalase, therefore it is classified as a non-metabolizable alcohol. Due to its biochemical properties, it is thought that it could be useful in the detection of hydroxyl radicals in vivo in intact cells..

It is one of the four isomers of isobutyl alcohol, the isomer being the least susceptible to oxidation and the least reactive. In nature, it is found in chickpeas and cassava or manioc, a root that is fermented to produce alcoholic beverages..

Tertiary butyl alcohol is very soluble in water and organic solvents. Its main use is as a solvent, fulfilling that role in the production of plastics, perfumes, paint removers, etc..

Like many organic compounds, it is a bit toxic, but in high doses it has a narcotic effect, characterized by headache, lightheadedness, dizziness, dizziness and lightheadedness..

Article index

  • 1 Structure of tert-butyl alcohol
  • 2 Properties
    • 2.1 Chemical names
    • 2.2 Molecular formula
    • 2.3 Molecular weight
    • 2.4 Physical description
    • 2.5 Odor
    • 2.6 Boiling point
    • 2.7 Melting point
    • 2.8 Flash point
    • 2.9 Solubility in water
    • 2.10 Solubility in organic solvents
    • 2.11 Density
    • 2.12 Vapor density
    • 2.13 Vapor pressure
    • 2.14 Octanol / water partition coefficient
    • 2.15 Thermostability
    • 2.16 Auto-ignition temperature
    • 2.17 Decomposition
    • 2.18 Heat of vaporization
    • 2.19 Caloric capacity
    • 2.20 Enthalpy of formation
    • 2.21 Storage temperature
    • 2.22 Stability
    • 2.23 Ionization potential
    • 2.24 Odor threshold
    • 2.25 Refractive index
    • 2.26 Dissociation constant
    • 2.27 Maximum vapor concentration
    • 2.28 Reactions
  • 3 Risks
  • 4 Uses
  • 5 References

Structure of tert-butyl alcohol

Tertiary butyl alcohol molecule. Source: Jynto via Wikipedia.

The upper image shows the molecular structure of tert-butyl alcohol with a model of spheres and bars. The entire molecule has a global tetrahedral geometry, with the 3rd carbon located in its center, and the CH groups3 and OH at its vertices.

Observing this structure it is understood why this alcohol is tertiary: the carbon in the center is linked to three other carbons. Continuing with the tetrahedron, the lower part of it can be considered apolar, while its upper vertex, polar.

At this vertex is the OH group, which creates a permanent dipole moment and also allows the t-BuOH molecules to interact through hydrogen bonds; in the same way as it does with water molecules and other polar substances.

In t-BuOH crystals these hydrogen bonds are a key factor for the molecules to stay together; although there is not much information regarding what is the crystalline structure of this alcohol.

As the OH group is so close and surrounded by the apolar groups CH3, the water molecules manage to hydrate almost all the alcohol at the same time that they interact with the OH. This would explain its great solubility in water..

Properties

Chemical names

-Tertiary butyl alcohol

-tert-butanol

-2- methyl-2-propanol

-2-methylpropan-2-ol.

Molecular formula

C4H10O or (CH3)3COH.

Molecular weight

74.123 g / mol.

Physical description

Colorless solid or colorless liquid, depending on the ambient temperature, since the melting point is 77.9ºF (25.4ºC). Above 77.9ºF it is a liquid.

Odor

Similar to camphor.

Boiling point

82.4 ºC.

Melting point

77.9 ºF (25.4 ºC).

ignition point

52 ° F (11 ° C). Closed cup.

Water solubility

Very soluble. In fact, regardless of the proportions, this alcohol is always miscible with water..

Solubility in organic solvents

Miscible with ethanol, ethyl ether and soluble in chloroform.

Density

0.78 g / cm3.

Vapor density

2.55 (relative to air = 1).

Vapor pressure

4.1 kPa at 20 ºC.

Octanol / water partition coefficient

Log P = 0.35.

Thermostability

Unstable in the heat

Auto-ignition temperature

896 ºF (470 ºC).

Decomposition

When heated, it can release carbon monoxide and isobutylene vapors.

Heat of vaporization

39.07 kJ / mol.

Caloric capacity

215.37 JK-1mole-1.

Formation enthalpy

-360.04 to -358.36 kJmol-1.

Storage temperature

2-8 ºC.

Stability

It is stable, but incompatible with strong oxidizing agents, copper, copper alloys, alkali metals and aluminum.

Ionization potential

9.70 eV.

Odor threshold

219 mg / m3 (low odor).

Refractive index

1,382 at 25 ºC.

Dissociation constant

pKa = 19.20.

Maximum vapor concentration

5.53% at 25 ºC.

Reactions

-It is deprotonated by a strong base to give rise to an alkoxide anion; specifically, a terbutoxide, (CH3)3CO-.

-Tertiary butyl alcohol reacts with hydrogen chloride to form tertiary butyl chloride..

(CH3)3COH + HCl => (CH3)3CCl + HtwoOR

Tertiary alcohols have greater reactivity with hydrogen halides than secondary and primary alcohols.

Risks

Tertiary butyl alcohol in contact with the skin causes minor lesions, such as non-severe erythema and hyperemia. Also, it does not pass through the skin. On the contrary, in the eyes it does produce severe irritation.

When inhaled, it irritates the nose, throat and bronchial tubes. In case of high exposure, narcotic effects, a state of drowsiness, as well as lightheadedness, dizziness and headache can occur..

This alcohol is an experimental teratogenic agent, which is why it has been observed in animals that it can influence the appearance of congenital disorders.

Regarding its storage, its liquid and vapors are flammable, and therefore in certain circumstances it can generate fires and explosions..

OSHA established a concentration limit of 100 ppm (300 mg / m3) for an 8 hour shift.

Applications

-Tert-butyl alcohol is used for the incorporation of the tert-butyl group in organic compounds, in order to prepare oil-soluble resins, and trinitro-tert-butyltoluene, an artificial musk. In addition, it constitutes a starting material for the preparation of peroxides.

-It has been approved by the FDA as a defoaming agent for use in plastic materials and components that come into contact with food. It has been used in the production of fruit essences, plastics and lacquers.

-It is an intermediate for the production of tert-butyl chloride and tributylphenol. Acts as a denaturing agent for ethanol.

-It is used for the manufacture of flotation agents, as an organic solvent to remove paints, and to dissolve essences used in perfumes..

-It is used as an octane enhancer in gasoline; fuel and fuel additive; solvent to be used in cleaning and as a degreaser.

-Tert-butyl alcohol is an intermediate agent in the production of tert-butylmethyl ether (MTBE) and tributylethyl ether (ETBE), reacting respectively with methanol and ethanol.

-It also acts in the same way in the production of tributyl hydroperoxide (TBHP) by reaction with hydrogen peroxide..

-It is used as a reagent in the process known as Curtius rearrangement..

References

  1. Graham Solomons T.W., Craig B. Fryhle. (2011). Organic Chemistry. Amines. (10th edition.). Wiley plus.
  2. Wikipedia. (2019). Tert-Butyl alcohol. Recovered from: en.wikipedia.org
  3. CommonOrganicChemistry. (s.f.). t-Butanol. Recovered from: commonorganicchemistry.com
  4. National Center for Biotechnology Information. (2019). Tert butanol. PubChem Database. Recovered from: pubchem.ncbi.nlm.nih.gov
  5. Carey F. A. (2008). Organic Chemistry. (Sixth edition). Mc Graw Hill.

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