methanediol

{{Redirect-distinguish|Methylene glycol|Ethylene glycol}}

{{Short description|Organic compound (CH2(OH)2); simplest geminal diol}}

{{Chembox

| Watchedfields = changed

| verifiedrevid = 447495694

| ImageFile2 = Methanediol-3D-balls.png

| ImageFile2_Ref = {{chemboximage|correct|??}}

| ImageSize2 = 100

| ImageName2 = Ball and stick model of the methanediol

| ImageFileL1 = Methanediol-2D.png

| ImageFileL1_Ref = {{chemboximage|correct|??}}

| ImageNameL1 = Skeletal formula of methanediol with some explicit hydrogens added

| ImageFileR1 = Methanediol-3D-vdW.png

| ImageFileR1_Ref = {{chemboximage|correct|??}}

| ImageNameR1 = Spacefill model of methanediol

| PIN = Methanediol{{Cite web|title = Methanediol - Compound Summary|url = https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=79015|work = PubChem Compound|publisher = National Center for Biotechnology Information|accessdate = 20 October 2011|location = USA|date = 26 March 2005|at = Identification and Related Records}}

| OtherNames = {{unbulleted list|Formaldehyde hydrate|Formaldehyde monohydrate|Methylene glycol}}

|Section1={{Chembox Identifiers

| Abbreviations = MADOL

| CASNo = 463-57-0

| CASNo_Ref = {{cascite|correct|??}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 6Z20YM9257

| PubChem = 79015

| ChemSpiderID = 71348

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| EINECS = 207-339-5

| ChEBI = 48397

| ChEBI_Ref = {{ebicite|correct|EBI}}

| Beilstein = 1730798

| SMILES = OCO

| StdInChI = 1S/CH4O2/c2-1-3/h2-3H,1H2

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = CKFGINPQOCXMAZ-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

}}

|Section2={{Chembox Properties

| C=1 | H=4 | O=2

| Appearance = Colourless liquid

| Density = {{val|1.199|u=g/cm3}} {{Citation needed|date=October 2021}}

| BoilingPtC = 194

| BoilingPt_notes = at 101 kPa {{Citation needed|date=October 2021}}

| VaporPressure = 16.1 Pa {{Citation needed|date=October 2021}}

| RefractIndex = 1.401 {{Citation needed|date=October 2021}}

| pKa = 13.29{{cite journal|last=Bell|first=R. P.|author2=McTigue, P. T.|title=603. Kinetics of the aldol condensation of acetaldehyde|journal=Journal of the Chemical Society (Resumed)|year=1960|pages=2983|doi=10.1039/JR9600002983}}

}}

|Section3={{Chembox Hazards

| FlashPtC = 99.753

}}

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Methanediol, also known as formaldehyde monohydrate or methylene glycol, is an organic compound with chemical formula {{chem2|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 ({{chem2|(CH2O)_{n} }}), formaldehyde ({{chem2|H2C\dO}}), and 1,3,5-trioxane ({{chem2|(CH2O)3}}).

Methanediol is a product of the hydration of formaldehyde. The equilibrium constant for hydration is estimated to be 10³,

Eric V. Anslyn, Dennis A. Dougherty (2006), [https://books.google.com/books?id=gY-Sxijk_tMC&pg=PA544 Modern physical organic chemistry]. University Science Books. {{ISBN|1-891389-31-9}}. 1095 pages{{chem2|CH2(OH)2}} predominates in dilute (<0.1%) solution. In more concentrated solutions, it oligomerizes to {{chem2|HO(CH2O)_{n}H}}.{{Ullmann|doi=10.1002/14356007.a11_619|title=Formaldehyde|year=2000|last1=Reuss|first1=Günther|last2=Disteldorf|first2=Walter|last3=Gamer|first3=Armin Otto|last4=Hilt|first4=Albrecht|isbn=3527306730}}