12-crown-4
Structural formula | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
General | ||||||||||||||||
Surname | [12] Crown-4 | |||||||||||||||
other names |
1,4,7,10-tetraoxacyclododecane |
|||||||||||||||
Molecular formula | C 8 H 16 O 4 | |||||||||||||||
Brief description |
colorless liquid |
|||||||||||||||
External identifiers / databases | ||||||||||||||||
|
||||||||||||||||
properties | ||||||||||||||||
Molar mass | 176.21 g mol −1 | |||||||||||||||
Physical state |
liquid |
|||||||||||||||
density |
1.089 g cm −3 (25 ° C) |
|||||||||||||||
Melting point |
16 ° C |
|||||||||||||||
boiling point |
61-70 ° C (0.5 mmHg) |
|||||||||||||||
Vapor pressure |
0.04 hPa (20 ° C) |
|||||||||||||||
solubility |
soluble in water |
|||||||||||||||
Refractive index |
1.463 (20 ° C) |
|||||||||||||||
safety instructions | ||||||||||||||||
|
||||||||||||||||
Toxicological data | ||||||||||||||||
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
[12] Crown-4 is a chemical compound from the group of crown ethers .
Extraction and presentation
[12] Crown-4 can be obtained by cyclizing tetraethylene glycol with lithium hydroxide . Synthesis by reaction of ethylene glycol with 1,8-dichloro-3,6-dioxaoctane in the presence of lithium perchlorate and sodium hydroxide and dimethyl sulfoxide as solvents is also possible .
properties
[12] Krone-4 is a colorless liquid that is soluble in water. It forms complexes with lithium ions, since the ion with its size of 120 pm fits very well into the interior of the compound.
Individual evidence
- ↑ a b c d e f g h i j k data sheet 12-Crown-4, Cyclic tetramer of ethylene oxide which is specific for the lithium cation. 98% from Sigma-Aldrich , accessed on September 5, 2015 ( PDF ).
- ↑ a b Data sheet 12-Krone-4 (PDF) from Merck , accessed on September 5, 2015.
- ↑ M. Hiraoka: Crown Ethers and Analogous Compounds . Elsevier, 2013, ISBN 978-1-4832-9087-4 , pp. 19 ( limited preview in Google Book search).
- ^ VK Ahluwalia, Renu Aggarwal: Organic Synthesis Special Techniques . CRC Press, 2001, ISBN 978-0-8493-1002-7 , pp. 73 ( limited preview in Google Book search).
- ↑ Paula Yurkanis Bruice: Organic Chemistry compact studying . Pearson Deutschland GmbH, 2011, ISBN 978-3-86894-102-9 , pp. 426 ( limited preview in Google Book search).