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15-Crown-5

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15-Crown-5
Skeletal formula
Ball-and-stick model
Names
Preferred IUPAC name 1,4,7,10,13-Pentaoxacyclopentadecane
Identifiers
CAS Number
3D model (JSmol)
Beilstein Reference 1618144
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.046.694 Edit this at Wikidata
EC Number
  • 251-379-6
Gmelin Reference 3897
MeSH 15-Crown-5
PubChem CID
RTECS number
  • SB0200000
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C10H20O5/c1-2-12-5-6-14-9-10-15-8-7-13-4-3-11-1/h1-10H2Key: VFTFKUDGYRBSAL-UHFFFAOYSA-N
  • InChI=1/C10H20O5/c1-2-12-5-6-14-9-10-15-8-7-13-4-3-11-1/h1-10H2Key: VFTFKUDGYRBSAL-UHFFFAOYAH
SMILES
  • C1COCCOCCOCCOCCO1
Properties
Chemical formula C10H20O5
Molar mass 220.265 g·mol
Appearance Clear, colorless liquid
Density 1.113 g cm (at 20 °C)
Boiling point 93–96 °C (199–205 °F; 366–369 K) at 0.05 mmHg
log P -0.639
Refractive index (nD) 1.465
Thermochemistry
Std enthalpy of
formation (ΔfH298) 		-881.1--877.1 kJ mol
Std enthalpy of
combustion (ΔcH298) 		-5.9157--5.9129 MJ mol
Hazards
GHS labelling:
Pictograms GHS07: Exclamation mark
Signal word Warning
Hazard statements H302, H315, H319
Precautionary statements P305+P351+P338
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2 1 0
Flash point 113 °C (235 °F; 386 K)
Safety data sheet (SDS) msds.chem.ox.ac.uk
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). checkY verify (what is  ?) Infobox references
Chemical compound

15-Crown-5 is a crown ether with the formula (C2H4O)5. It is a cyclic pentamer of ethylene oxide that forms complex with various cations, including sodium (Na) and potassium (K); however, it is complementary to Na and thus has a higher selectivity for Na ions.

Synthesis

15-Crown-5 can be synthesized using a modified Williamson ether synthesis:

(CH2OCH2CH2Cl)2 + O(CH2CH2OH)2 + 2 NaOH → (CH2CH2O)5 + 2 NaCl + 2 H2O

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

Properties

Analogous to 18-crown-6, 15-crown-5 binds to sodium ions. Thus, when treated with this complexing agent, sodium salts often become soluble in organic solvents.

First-row transition metal dications fit snugly inside the cavity of 15-crown-5. They are too small to be included in 18-crown-6. The binding of transition metal cations results in multiple hydrogen-bonded interactions from both equatorial and axial aqua ligands, such that highly crystalline solid-state supramolecular polymers can be isolated. Metal salts isolated in this form include Co(ClO4)2, Ni(ClO4)2, Cu(ClO4)2, and Zn(ClO4)2. Seven coordinate species are most common for transition metal complexes of 15-crown-5, with the crown ether occupying the equatorial plane, along with 2 axial aqua ligands.

The structure of the complex .

15-crown-5 has also been used to isolate salts of oxonium ions. For example, from a solution of tetrachloroauric acid, the oxonium ion has been isolated as the salt . Neutron diffraction studies revealed a sandwich structure, which shows a chain of water with remarkably long O-H bond (1.12 Å) in the acidic proton, but with a very short OH•••O distance (1.32 Å).

Structure of ion

A derivative of 15-crown-5, benzo-15-crown-5, has been used to produce anionic complexes of carbido ligands as their salts:

(Ar2N)3MoCH + KCH2Ph + 2 (15-crown-5) → + CH3Ph

See also

References

  1. "15-crown-5 - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. Retrieved 11 October 2011.
  2. Takeda, Y.; et al. (1988). "A Conductance Study of 1:1 Complexes of 15-Crown-5, 16-Crown-5, and Benzo-15-crown-5 with Alkali Metal Ions in Nonaqueous Solvents". Bulletin of the Chemical Society of Japan. 61 (3): 627–632. doi:10.1246/bcsj.61.627.
  3. Chen, Chun-Yen; et al. (2006). "Potassium ion recognition by 15-crown-5 functionalized CdSe/ZnS quantum dots in H2O". Chem. Comm. (3): 263–265. doi:10.1039/B512677K. PMID 16391728.
  4. 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.
  5. Liotta, Charles L.; Berkner, Joachim (2001), "15-Crown-5", Encyclopedia of Reagents for Organic Synthesis, Chichester, UK: John Wiley & Sons, Ltd, doi:10.1002/047084289x.rc263, ISBN 978-0-471-93623-7
  6. ^ Jonathan W. Steed; Jerry L. Atwood (2009). Supramolecular Chemistry, 2nd edition. Wiley. ISBN 978-0-470-51233-3.

Further reading

External links

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