12-Crown-4

12-Crown-4
Names
	Preferred IUPAC name 1,4,7,10-Tetraoxacyclododecane
	Other names 12-crown-4, Lithium Ionophore V
Identifiers
CAS Number	294-93-9 ;
3D model (JSmol)	Interactive image; Interactive image;
Beilstein Reference	1363064
ChEBI	CHEBI:32399 ;
ChemSpider	8912 ;
ECHA InfoCard	100.005.488
EC Number	206-036-5;
Gmelin Reference	3287
PubChem CID	9269;
UNII	K6069P2C2A;
CompTox Dashboard (EPA)	DTXSID6059780 ;
	InChI InChI=1S/C8H16O4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h1-8H2 Key: XQQZRZQVBFHBHL-UHFFFAOYSA-N ; InChI=1/C8H16O4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h1-8H2 Key: XQQZRZQVBFHBHL-UHFFFAOYAA;
	SMILES O1CCOCCOCCOCC1; C1COCCOCCOCCO1;
Properties
Chemical formula	C8H16O4
Molar mass	176.21
Density	1.089 g/mL at 25 °C
Melting point	16 °C
Boiling point	61-70 °C/0.5 mm Hg
Solubility in water	Miscible
Hazards
Flash point	113 °C (235 °F; 386 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

12-Crown-4, also called 1,4,7,10-tetraoxacyclododecane and lithium ionophore V, is a crown ether with the formula C₈H₁₆O₄. It is a cyclic tetramer of ethylene oxide which is specific for the lithium cation.

Synthesis

12-Crown-4 can be synthesized using a modified Williamson ether synthesis, using LiClO₄ as a templating cation:^[1]

(CH₂OCH₂CH₂Cl)₂ + (CH₂OH)₂ + 2 NaOH → (CH₂CH₂O)₄ + 2 NaCl + 2 H₂O

It also forms from the cyclic oligomerization of ethylene oxide in the presence of gaseous boron trifluoride.^[2]

Properties

Ball-and-stick model of the bis(12-crown-4)lithium cation

Like other crown ethers, 12-crown-4 complexes with alkali metal cations. The cavity diameter of 1.2-1.5 Å gives it a high selectivity towards the lithium cation (ionic diameter 1.36 Å)^[2]

Its point group is S₄. The dipole moment of 12-crown-4 varies with solvent and temperature. At 25 °C, the dipole moment of 12-crown-4 was determined as 2.33 ± 0.03 D in cyclohexane and 2.46 ± 0.01 D in benzene.^[3]

References

^ Cook, Fred L.; Caruso, Thomas C.; Byrne, Michael P.; Bowers, Chauncey W.; Speck, Don H.; Liotta, Charles L. (1974). "Facile syntheses of 12-crown-4 and 15-crown-5". Tetrahedron Letters. 15 (46): 4029–4032. doi:10.1016/S0040-4039(01)92075-1.
^ ^a ^b Liotta, Charles L.; Berkner, Joachim (2001), "12-Crown-4", Encyclopedia of Reagents for Organic Synthesis, Chichester, UK: John Wiley & Sons, Ltd, doi:10.1002/047084289X.rc262, ISBN 978-0-471-93623-7
^ Caswell, Lyman R.; Savannunt, Diana S. (January 1988). "Temperature and solvent effects on the experimental dipole moments of three crown ethers". Journal of Heterocyclic Chemistry. 25 (1): 73–79. doi:10.1002/jhet.5570250111.

Sigma-Aldrich Handbook of Fine Chemicals, 2007, page 768.
Sigma-Aldrich Cyclic tetramer of ethylene oxide which is specific for the lithium cation. 98%, 2018

Synthesis

Properties

References

See also