2.2.2-Cryptand
{{correct title|[2.2.2]Cryptand|reason=bracket|edit=omission}}
{{Chembox
| Name = [2.2.2]Cryptand
| Watchedfields = changed
| verifiedrevid = 477215715
| ImageFile = Cryptand.svg
| ImageName = Skeletal formula of 2.2.2-cryptand
| ImageSize = 150
| ImageFile1 = 2.2.2-Cryptand-3D-balls-by-AHRLS-2012.png
| ImageSize1 = 150
| ImageFileL2 = 2.2.2-Cryptand-3D-sticks-by-AHRLS-2012.png
| ImageSizeL2 = 140
| ImageFileR2 = 2.2.2-Cryptand-3D-vdW-by-AHRLS-2012.png
| ImageSizeR2 = 140
| PIN = 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane
| OtherNames = Cryptating agent 222In the Nomenclature of Inorganic Chemistry (2005), IUPAC recommends the abbreviation crypt-222.
|Section1={{Chembox Identifiers
| Abbreviations = Crypt-222
| CASNo = 23978-09-8
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 18V22YHN6G
| PubChem = 72801
| ChemSpiderID = 65637
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 245-962-4
| MeSHName = Cryptating+agent+222
| RTECS = MP4750000
| Beilstein = 620282
| SMILES = C1COCCN2CCOCCOCCN(CCO1)CCOCCOCC2
| StdInChI = 1S/C18H36N2O6/c1-7-21-13-14-24-10-4-20-5-11-25-17-15-22-8-2-19(1)3-9-23-16-18-26-12-6-20/h1-18H2
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| InChI = 1/C18H36N2O6/c1-7-21-13-14-24-10-4-20-5-11-25-17-15-22-8-2-19(1)3-9-23-16-18-26-12-6-20/h1-18H2
| StdInChIKey = AUFVJZSDSXXFOI-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| InChIKey = AUFVJZSDSXXFOI-UHFFFAOYAX
}}
|Section2={{Chembox Properties
| Formula = {{Chem|C|18|N|2|H|36|O|6}}
| MolarMass = 376.4882 g mol−1
| MeltingPtC = 68 to 71
}}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS exclamation mark}}
| GHSSignalWord = WARNING
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|261|305+351+338}}
}}
}}
[2.2.2]Cryptand is the organic compound with the formula N(CH2CH2OCH2CH2OCH2CH2)3N. This bicyclic molecule is the most studied member of the cryptand family of chelating agents.{{cite journal|last1=Kang|first1=Sung Ok|last2=Llinares|first2=José M.|last3=Day|first3=Victor W.|last4=Bowman-James|first4=Kristin|author-link4=Kristin Bowman-James|year=2010|title=Cryptand-like anion receptors|journal=Chemical Society Reviews|volume=39|issue=10|pages=3980–4003|doi=10.1039/C0CS00083C|pmid=20820597}} It is a white solid. Many analogous compounds are known. Their high affinity for alkali metal cations illustrates the advantages of "preorganization", a concept within the area of supramolecular chemistry.
For the design and synthesis of [2.2.2]cryptand,{{cite journal |doi=10.1016/S0040-4039(01)88300-3|title=Les Cryptates|year=1969|last1=Dietrich|first1=B.|last2=Lehn|first2=J.M.|last3=Sauvage|first3=J.P.|journal=Tetrahedron Letters|volume=10|issue=34|pages=2889–2892}} Jean-Marie Lehn shared the Nobel Prize in Chemistry. The compound was originally prepared starting with the diacylation of the diamine-diether:{{cite journal |doi=10.1016/S0040-4039(01)88299-X|title=Diaza-polyoxa-macrocycles et macrobicycles|year=1969|last1=Dietrich|first1=B.|last2=Lehn|first2=J.M.|last3=Sauvage|first3=J.P.|journal=Tetrahedron Letters|volume=10|issue=34|pages=2885–2888}}
:[CH2OCH2CH2NH2]2 + [CH2OCH2COCl]2 → [CH2OCH2CH2NHC(O)CH2]2 + 2 HCl
The resulting macrocyclic diamide is reduced by lithium aluminium hydride. The resulting macrocyclic diamine tetraether reacts with a second equivalent of [CH2OCH2COCl]2 to produce the macrobicyclic diamide. This di(tertiary)amide is reduced to the diamine by diborane.
[2.2.2]Cryptand binds K+ as an octadentate N2O6 ligand. The resulting cation K([2.2.2]cryptand)+ is lipophilic.
Image:Cryptate of potassium cation.jpg cation (purple) as determined by X-ray crystallography{{cite journal |author1=Alberto, R. |author2=Ortner, K. |author3=Wheatley, N. |author4=Schibli, R. |author5=Schubiger, A. P. | title = Synthesis and properties of boranocarbonate: a convenient in situ CO source for the aqueous preparation of [99mTc(OH2)3(CO)3]+ | journal = J. Am. Chem. Soc. | year = 2001 | volume = 121 | pages = 3135–3136 | doi = 10.1021/ja003932b |pmid=11457025 | issue = 13}}]]{{clear-left}}
