Synthesis, complexation properties and crystal structure of 4′,5-dibromo-o-xylyl-17-crown-5 ether

4′, 5′-Dibromc-o-xylyl-17-crown-5 ether (2BrB17C5) was synthesized, starting from 1,2-dibromo-4,5-bis(bromomethyl)-benzene and tetraethylene glycol, and was characterized by ¹H NMR, MS and elemental analysis. Pale yellow prismatic single crystal obtained from anhydrous ethanol was investigated by X-ray structural analysis. The complexation properties toward alkali metal ions were examined using the solvent extraction method and UV absorption spectroscopy. The crown ether was found to be conformationally deformed and oblate-like and is highly selective for lithium ion.