Synthesis and Lithium Ion-Selectivity of 2-Phenylcyclohexano- and 2,3- Diphenylcyclohexano-14-crown-4 Derivatives.

Cis- and trans-2-phenylcyclohexano-14-crown-4 and cis- and trans-2,3-diphenylcyclohexano-14-crown-4 were prepared and their ion selectivity was determined by means of extraction of alkali metal picrates, stability constants, and ion-selective electrodes. Cis diphenyl derivative exhibits the highest lithium ion-selectivity of the four ionophores examined, which is as high as that of decalino-14-crown-4, one of the best Li+-selective ionophores.