Tetrahydrofuran

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Tetrahydrofuran
Skeletal formula of tetrahydrofuran
Skeletal formula of tetrahydrofuran
Ball-and-stick model of the tetrahydrofuran molecule
Ball-and-stick model of the tetrahydrofuran molecule
Photograph of a glass bottle of tetrahydrofuran
Names
Preferred IUPAC name
Oxolane[1]
Systematic IUPAC name
1,4-Epoxybutane
1-Oxacyclopentane
Other names
Tetrahydrofuran
THF
1,4-Butylene oxide
Cyclotetramethylene oxide fraction
Furanidin
Tetra-methylene oxide, Oxolane
Identifiers
3D model (
JSmol
)
Abbreviations THF
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
100.003.389 Edit this at Wikidata
RTECS number
  • LU5950000
UNII
  • InChI=1S/C4H8O/c1-2-4-5-3-1/h1-4H2 checkY
    Key: WYURNTSHIVDZCO-UHFFFAOYSA-N checkY
  • InChI=1/C4H8O/c1-2-4-5-3-1/h1-4H2
    Key: WYURNTSHIVDZCO-UHFFFAOYAI
SMILES
  • C1CCOC1
Properties
C4H8O
Molar mass 72.107 g·mol−1
Appearance Colorless liquid
Odor Ether-like[2]
Density 0.8876 g/cm3 at 20 °C, liquid [3]
Melting point −108.4 °C (−163.1 °F; 164.8 K)
Boiling point 66 °C (151 °F; 339 K)[4][3]
Miscible
Vapor pressure 132 mmHg at 20 °C[2]
1.4073 at 20 °C[3]
Viscosity 0.48 cP at 25 °C
Structure
Envelope
1.63 D (gas)
Hazards
GHS labelling:
GHS02: Flammable GHS07: Exclamation mark GHS08: Health hazard[5]
Danger
H225, H302, H319, H335, H351[5]
P210, P280, P301+P312+P330, P305+P351+P338, P370+P378, P403+P235[5]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
3
1
Flash point −14 °C (7 °F; 259 K)
Explosive limits
2–11.8%[2]
Lethal dose or concentration (LD, LC):
  • 1650 mg/kg (rat, oral)
  • 2300 mg/kg (mouse, oral)
  • 2300 mg/kg (guinea pig, oral)[6]
21000 ppm (rat, 3 h)[6]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 200 ppm (590 mg/m3)[2]
REL (Recommended)
TWA 200 ppm (590 mg/m3) ST 250 ppm (735 mg/m3)[2]
IDLH
(Immediate danger)
2000 ppm[2]
Related compounds
Related
heterocycles
Dioxane
Related compounds
Diethyl ether
Supplementary data page
Tetrahydrofuran (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Tetrahydrofuran (THF), or oxolane, is an

polar and having a wide liquid range, THF is a versatile solvent. It is an isomer of another solvent, butanone
.

Production

About 200,000

oxidizing n-butane to crude maleic anhydride, followed by catalytic hydrogenation.[10] A third major industrial route entails hydroformylation of allyl alcohol followed by hydrogenation to 1,4-butanediol
.

Other methods

THF can also be synthesized by catalytic hydrogenation of furan.[11][12] This allows certain sugars to be converted to THF via acid-catalyzed digestion to furfural and decarbonylation to furan,[13] although this method is not widely practiced. THF is thus derivable from renewable resources.

Applications

Polymerization

In the presence of

poly(tetramethylene ether) glycol
(PTMEG), also known as polytetramethylene oxide (PTMO):

This polymer is primarily used to make

elastomeric polyurethane fibers like Spandex.[14]

As a solvent

The other main application of THF is as an industrial solvent for

dielectric constant of 7.6. It is a moderately polar solvent and can dissolve a wide range of nonpolar and polar chemical compounds.[15] THF is water-miscible and can form solid clathrate hydrate structures with water at low temperatures.[16]

THF has been explored as a miscible co-solvent in aqueous solution to aid in the liquefaction and delignification of plant

glycans
from biomass and dissolves the majority of biomass lignin making it a suitable solvent for biomass pretreatment.

THF is often used in polymer science. For example, it can be used to dissolve

polymers prior to determining their molecular mass using gel permeation chromatography. THF dissolves PVC as well, and thus it is the main ingredient in PVC adhesives. It can be used to liquefy old PVC cement and is often used industrially to degrease
metal parts.

THF is used as a component in mobile phases for

reversed-phase liquid chromatography. It has a greater elution strength than methanol or acetonitrile
, but is less commonly used than these solvents.

THF is used as a solvent in 3D printing when printing with

solvent weld
printed parts.

Laboratory use

In the laboratory, THF is a popular solvent when its water miscibility is not an issue. It is more

Thus, while diethyl ether remains the solvent of choice for some reactions (e.g., Grignard reactions), THF fills that role in many others, where strong coordination is desirable and the precise properties of ethereal solvents such as these (alone and in mixtures and at various temperatures) allows fine-tuning modern chemical reactions.

Commercial THF contains substantial water that must be removed for sensitive operations, e.g. those involving

organometallic compounds. Although THF is traditionally dried by distillation from an aggressive desiccant such as elemental sodium, molecular sieves have been shown to be superior water scavengers.[20]

Reaction with hydrogen sulfide

In the presence of a

Lewis basicity

Structure of VCl3(thf)3.[22]

THF is a Lewis base that bonds to a variety of

triethylaluminum and bis(hexafluoroacetylacetonato)copper(II). THF has been classified in the ECW model and it has been shown that there is no one order of base strengths.[23] Many complexes are of the stoichiometry MCl3(THF)3.[24]

Precautions

THF is a relatively acutely nontoxic solvent, with the median lethal dose (LD50) comparable to that for acetone. However, chronic exposure is suspected of causing cancer.[5][25] Reflecting its remarkable solvent properties, it penetrates the skin, causing rapid dehydration. THF readily dissolves latex and thus should be handled with nitrile rubber gloves. It is highly flammable.

One danger posed by THF is its tendency to form the explosive compound

2-hydroperoxytetrahydrofuran
upon reaction with air:

To minimize this problem, commercial supplies of THF are often stabilized with butylated hydroxytoluene (BHT). Distillation of THF to dryness is unsafe because the explosive peroxides can concentrate in the residue.

Tetrahydrofurans

Chemical structure of annonacin, an acetogenin.
anticancer drug
.

The tetrahydrofuran ring is found in diverse natural products including lignans, acetogenins, and polyketide natural products.[26] Diverse methodology has been developed for the synthesis of substituted THFs.[27]

Oxolanes

Tetrahydrofuran is one of the class of pentic cyclic ethers called oxolanes. There are seven possible structures, namely,[28]

  • Monoxolane, the root of the group, synonymous with tetrahydrofuran
  • 1,3-dioxolane
  • 1,2-dioxolane
  • 1,2,4-trioxolane
  • 1,2,3-trioxolane
  • tetroxolane
  • pentoxolane

See also

References

  1. ^ "New IUPAC Organic Nomenclature - Chemical Information BULLETIN" (PDF).
  2. ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0602". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ .
  4. ^ NIST Chemistry WebBook. http://webbook.nist.gov
  5. ^ a b c d Record of Tetrahydrofuran in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2 June 2020.
  6. ^ a b "Tetrahydrofuran". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  7. ^ "New Environment Inc. - NFPA Chemicals". Newenv.com. Retrieved 2016-07-16.
  8. ^ .
  9. ^ Karas, Lawrence; Piel, W. J. (2004). "Ethers". Kirk‑Othmer Encyclopedia of Chemical Technology. John Wiley & Sons.
  10. ^ Morrison, Robert Thornton; Boyd, Robert Neilson (1972). Organic Chemistry (2nd ed.). Allyn and Bacon. p. 569.
  11. ^ Starr, Donald; Hixon, R. M. (1943). "Tetrahydrofuran". Organic Syntheses; Collected Volumes, vol. 2, p. 566.
  12. ^ Pruckmayr, Gerfried; Dreyfuss, P.; Dreyfuss, M. P. (1996). "Polyethers, Tetrahydrofuran and Oxetane Polymers". Kirk‑Othmer Encyclopedia of Chemical Technology. John Wiley & Sons.
  13. ^ "Chemical Reactivity". Michigan State University. Archived from the original on 2010-03-16. Retrieved 2010-02-15.
  14. ^ "NMR–MRI study of clathrate hydrate mechanisms" (PDF). Fileave.com. Archived from the original (PDF) on 2011-07-11. Retrieved 2010-02-15.
  15. .
  16. .
  17. .
  18. .
  19. .
  20. .
  21. .
  22. ^ Manzer, L. E. "Tetrahydrofuran Complexes of Selected Early Transition Metals," Inorganic Synthesis. 21, 135–140, (1982).
  23. ^ "Material Safety Data Sheet Tetrahydrofuran, 99.5+%, for spectroscopy". Fisher Scientific. Retrieved 2022-07-27.
  24. PMID 23506053
    .
  25. .
  26. .

General reference