We are working on the synthesis of functionalized crown ethers.However, we are getting sticky product. suggest good solvent for crystallization of functionalized crown ethers.
actually this depends on the nature of your crown type .you know different functional group meaning different polarity behavior , so different in solubility .
You find here somme answers:
1. Molecular and crystal structure of crown ethers containing biphenyl fragment:
http://www.sciencedirect.com/science/article/pii/S0022286006006995
2. Design of conductive crown ether based columnar liquid crystals: impact of molecular flexibility and geometry: http://pubs.rsc.org/en/Content/ArticleLanding/2013/TC/C2TC00284A#!divAbstract
3. Twelve-membered crown ethers: Crystal structures of benzo-12-crown-4 and naphtho-12-crown-4: http://link.springer.com/article/10.1007%2FBF00706476
There is a direct link to an e-thesis about the same subject: http://edoc.unibas.ch/507/1/DissB_7679.pdf
The 12-membered crown ethers have usually high m.p. Depending on substituents after chromatographic purification it is no problem with crystallization. In some cases the column chromatography could be replaced by crystallization from boiling petroleum (or higher boiling fractions). In this case the less polar component of the reaction product is the best soluble. By this way the compound of interest could be satisfactorily isolated.
please refer to The Chemist's Companion book then check "solvent polarity for crystalisation" section
The sticky nature of the crown suggests long alkyl groups attached to the core. It is also possible, that you have a mixture of isomeric substituted crowns. Then the properties are understandable. Sorry, I could not suggest more solutions. Crystallization is frequently unpredictable.
Regards,
J
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