2.2.2-Cryptand
[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. 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.
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Names | |||
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Preferred IUPAC name
4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane | |||
Other names
Cryptating agent 222 | |||
Identifiers | |||
3D model (JSmol) |
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Abbreviations | Crypt-222 | ||
620282 | |||
ChemSpider | |||
ECHA InfoCard | 100.041.770 | ||
EC Number |
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MeSH | Cryptating+agent+222 | ||
PubChem CID |
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RTECS number |
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UNII | |||
CompTox Dashboard (EPA) |
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SMILES
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Properties | |||
C 18N 2H 36O 6 | |||
Molar mass | 376.4882 g mol−1 | ||
Melting point | 68 to 71 °C (154 to 160 °F; 341 to 344 K) | ||
Hazards | |||
GHS labelling: | |||
Warning | |||
H315, H319, H335 | |||
P261, P305+P351+P338 | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references |
For the design and synthesis of [2.2.2]cryptand, Jean-Marie Lehn shared the Nobel Prize in Chemistry. The compound was originally prepared starting with the diacylation of the diamine-diether:
- [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.