12-Crown-4

changed 477208843 12-crown-4 skeletal.svg skin-invert 125 Skeletal formula of 12-crown-4 12-Crown-4-3D-balls.png bg-transparent 135 Ball-and-stick model of the 12-Crown-4 molecule 1,4,7,10-Tetraoxacyclododecane 12-crown-4, Lithium Ionophore V correct chemspider correct EBI 32399 8912 9269 206-036-5 K6069P2C2A 1363064 3287 1/C8H16O4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h1-8H2 XQQZRZQVBFHBHL-UHFFFAOYAA C1COCCOCCOCCO1 correct chemspider 1S/C8H16O4/c1-2-10-5-6-12-8-7-11-4-3-9-1/h1-8H2 correct chemspider XQQZRZQVBFHBHL-UHFFFAOYSA-N correct CAS 294-93-9 O1CCOCCOCCOCC1 C8H16O4 176.21 1.089 g/mL at 25 °C 16 °C 61-70 °C/0.5 mm Hg Miscible 113 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: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 en 15 46 4029–4032 10.1016/S0040-4039(01)92075-1 (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.Liotta Charles L. 12-Crown-4 2001 Encyclopedia of Reagents for Organic Synthesis Chichester, UK John Wiley & Sons, Ltd en 10.1002/047084289X.rc262 978-0-471-93623-7 Berkner Joachim Properties 200px|thumb|left|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) 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.Caswell Lyman R. Savannunt Diana S. Temperature and solvent effects on the experimental dipole moments of three crown ethers Journal of Heterocyclic Chemistry January 1988 25 1 73–79 10.1002/jhet.5570250111 References 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 See also Crown ether Cyclen, a similar molecule with N atoms (aza groups) instead of O atoms (ethers) Category:Crown ethers Category:Twelve-membered rings