Methanediol

Organic compound (CH2(OH)2); simplest geminal diol

Methanediol

Names

Preferred IUPAC name

Methanediol^[1]

Other names

Formaldehyde hydrate
Formaldehyde monohydrate
Methylene glycol

Identifiers

CAS Number

463-57-0^Y

3D model (JSmol)

Interactive image

Abbreviations

MADOL

Beilstein Reference

1730798

ChEBI

CHEBI:48397^Y

ChemSpider

71348^Y

ECHA InfoCard

100.006.673

EC Number

207-339-5

PubChem CID

79015

UNII

6Z20YM9257^Y

CompTox Dashboard (EPA)

DTXSID50196801

InChI

InChI=1S/CH4O2/c2-1-3/h2-3H,1H2^Y
Key: CKFGINPQOCXMAZ-UHFFFAOYSA-N^Y

SMILES

Properties

Chemical formula

CH₄O₂

Molar mass

48.041 g·mol⁻¹

Appearance

Colourless liquid

Density

1.199 g/cm³ ^{[citation needed]}

Boiling point

194 °C (381 °F; 467 K) at 101 kPa ^{[citation needed]}

Vapor pressure

16.1 Pa ^{[citation needed]}

Acidity (pK_a)

13.29^[2]

Refractive index (n_D)

1.401 ^{[citation needed]}

Hazards

Flash point

99.753 °C (211.555 °F; 372.903 K)

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Y verify (what is ^YN ?)

Infobox references

Chemical compound

Methanediol, also known as formaldehyde monohydrate or methylene glycol, is an organic compound with chemical formula CH₂(OH)₂. It is the simplest geminal diol. In aqueous solutions it coexists with oligomers (short polymers). The compound is closely related and convertible to the industrially significant derivatives paraformaldehyde ((CH₂O)_n), formaldehyde (H₂C=O), and 1,3,5-trioxane ((CH₂O)₃).^[3]

Methanediol is a product of the hydration of formaldehyde. The equilibrium constant for hydration is estimated to be 10³,^[4]CH₂(OH)₂ predominates in dilute (<0.1%) solution. In more concentrated solutions, it oligomerizes to HO(CH₂O)_nH.^[3]

Occurrence

The dianion, methanediolate, is believed to be an intermediate in the crossed Cannizzaro reaction.

Gaseous methanediols can be generated by electron irradiation and sublimation of a mixture of methanol and oxygen ices.^[5]

Methanediol is believed to occur as an intermediate in the decomposition of carbonyl compounds in the atmosphere, and as a product of ozonolysis on these compounds.^[5]

Safety

Methanediol, rather than formaldehyde, is listed as one of the main ingredients of "Brazilian blowout", a hair-straightening formula marketed in the United States. The equilibrium with formaldehyde has caused concern since formaldehyde in hair straighteners is a health hazard.^[6]^[7] Research funded by the Professional Keratin Smoothing Council (PKSC), an industry association that represents selected manufacturers of professional-use only keratin smoothing products, has disputed the risk.^[8]

References

^ "Methanediol - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 20 October 2011.
^ Bell, R. P.; McTigue, P. T. (1960). "603. Kinetics of the aldol condensation of acetaldehyde". Journal of the Chemical Society (Resumed): 2983. doi:10.1039/JR9600002983.
^ ^a ^b Reuss, Günther; Disteldorf, Walter; Gamer, Armin Otto; Hilt, Albrecht (2000). "Formaldehyde". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_619. ISBN 978-3527306732.
^ Eric V. Anslyn, Dennis A. Dougherty (2006), Modern physical organic chemistry. University Science Books. ISBN 1-891389-31-9. 1095 pages
^ ^a ^b Zhu, Cheng; Kleimeier, N. Fabian; Turner, Andrew M.; Singh, Santosh K.; Fortenberry, Ryan C.; Kaiser, Ralf I. (4 January 2022). "Synthesis of methanediol [CH 2 (OH) 2 ]: The simplest geminal diol". Proceedings of the National Academy of Sciences. 119 (1): e2111938119. Bibcode:2022PNAS..11911938Z. doi:10.1073/pnas.2111938119. PMC 8740743. PMID 34969838.
^ "Hair Smoothing Products That Could Release Formaldehyde". www.osha.gov. Occupational Safety and Health Administration.
^ SpecialChem. "Industry News".
^ Golden, R.; Valentini, M. (July 2014). "Formaldehyde and methylene glycol equivalence: Critical assessment of chemical and toxicological aspects". Regulatory Toxicology and Pharmacology. 69 (2): 178–186. doi:10.1016/j.yrtph.2014.03.007. PMID 24709515.

Alcohols

By consumption

Alcohols found in alcoholic drinks	1-Propanol 2-Methyl-1-butanol Ethanol Isoamyl alcohol Isobutanol Phenethyl alcohol tert-Amyl alcohol tert-Butyl alcohol Tryptophol
Medical alcohol	Ethchlorvynol Methylpentynol Methanol poisoning Ethanol
Toxic alcohols	Isopropyl alcohol Methanol

Primary
alcohols (1°)

Methanol	4-Methylcyclohexanemethanol Aminomethanol Cyclohexylmethanol Methoxymethanol Methylazoxymethanol Trifluoromethanol
Ethanol	1-Aminoethanol 2,2,2-Trichloroethanol 2,2,2-Trifluoroethanol 2-(2-Ethoxyethoxy)ethanol 2-(2-Methoxyethoxy)ethanol 2-(2-Methoxyethoxy)ethanol 2-Butoxyethanol 2-Chloroethanol 2-Ethoxyethanol 2-Fluoroethanol 2-Mercaptoethanol 2-Methoxyethanol Aminoethylethanolamine Diethylethanolamine Dimethylethanolamine Ethanol Ethanolamine N,N-Diisopropylaminoethanol N-Methylethanolamine Phenoxyethanol Tribromoethanol
Butanol	2-Methyl-1-butanol Isobutanol n-Butanol
Straight-chain saturated C₁ — C₉	Methanol Ethanol 1-Propanol 1-Butanol 1-Pentanol 1-Hexanol 1-Heptanol 1-Octanol (capryl) 1-Nonanol (pelargonic)
Straight-chain saturated C₁₀ — C₁₉	1-Decanol (capric) 1-Undecanol (hendecyl) 1-Dodecanol (lauryl) 1-Tridecanol 1-Tetradecanol (myristyl) 1-Pentadecanol 1-Hexadecanol (cetyl / palmityl) 1-Heptadecanol 1-Octadecanol (stearyl) 1-Nonadecanol
Straight-chain saturated C₂₀ — C₂₉	1-Icosanol (arachidyl) 1-Heneicosanol 1-Docosanol (behenyl) 1-Tricosanol 1-Tetracosanol (lignoceryl) 1-Pentacosanol 1-Hexacosanol (ceryl) 1-Heptacosanol 1-Octacosanol (cluytyl / montanyl) 1-Nonacosanol
Straight-chain saturated C₃₀ — C₃₉	1-Triacontanol (melissyl / myricyl) 1-Hentriacontanol 1-Dotriacontanol (lacceryl) 1-Tritriacontanol 1-Tetratriacontanol (geddyl) 1-Pentatriacontanol 1-Hexatriacontanol 1-Heptatriacontanol 1-Octatriacontanol 1-Nonatriacontanol
Straight-chain saturated C₄₀ — C₄₉	1-Tetracontanol 1-Hentetracontanol 1-Dotetracontanol 1-Tritetracontanol 1-Tetratetracontanol 1-Pentatetracontanol 1-Hexatetracontanol 1-Heptatetracontanol 1-Octatetracontanol 1-Nonatetracontanol

Secondary
alcohols (2°)

2-Deoxyerythritol

Propylene glycol methyl ether

Tertiary
alcohols (3°)

2-Methyl-2-pentanol
2-Methylheptan-2-ol
2-Methylhexan-2-ol
3-Methyl-3-pentanol
3-Methyloctan-3-ol
Diacetone alcohol
Ethchlorvynol
Methylpentynol
Nonafluoro-tert-butyl alcohol
tert-Amyl alcohol
tert-Butyl alcohol
Triphenylethanol
Triphenylmethanol

Hydric alcohols

Monohydric alcohols	Methanol (C₁) Ethanol (C₂) Isopropanol (C₃) 1-Butanol (C₄) 1-Pentanol (C₅) Cetyl alcohol (C₁₆)
Dihydric alcohols	Ethylene glycol Propylene glycol
Trihydric alcohols	Glycerol
Polyhydric alcohols (sugar alcohols)	Pentaerythritol Ethylene glycol (C₂) Glycerol, Propylene glycol (C₃) Erythritol, Threitol (C₄) Xylitol (C₅) Mannitol, Sorbitol (C₆) Volemitol (C₇)

Amyl alcohols

Aromatic alcohols

Saturated
fatty alcohols

Branched and
unsaturated
fatty alcohols

3-Methyl-3-pentanol
Erucyl alcohol
Linolenyl alcohol
Linoleyl alcohol
Oleyl alcohol
Palmitoleyl alcohol
tert-Amyl alcohol
tert-Butyl alcohol

Sugar alcohols

C₁ — C₇	Methylene glycol (C₁) Ethylene glycol (C₂) Glycerol (C₃) Erythritol (C₄) Threitol (C₄) Arabitol (C₅) Ribitol (C₅) Xylitol (C₅) Mannitol (C₆) Sorbitol (C₆) Galactitol (C₆) Iditol (C₆) Volemitol (C₇)
Deoxy sugar alcohols	Fucitol
Cyclic sugar alcohols	Inositol
Glycylglycitols	Maltitol Lactitol Isomalt Maltotriitol Maltotetraitol Polyglycitol

Terpene alcohols

Monoterpene alcohols	Borneol Citronellol Geraniol Linalool Menthol Nerol Rhodinol Terpineol
Sesquiterpene alcohols	Bisabolol Farnesol Nerolidol Patchoulol
Diterpene alcohols	Phytol