| Abstract: | Abstract Six kinds of lipopholic 16-crown-5 derivatives possessing double side-chains were synthesized. The Na+-selectivities were examined with poly(vinyl chloride) (PVC) matrix-membrane electrodes using these crown compounds. It is an effective way for obtaining high Na+-selectivity by introducing a bulky side-chain such as a benzyloxymethyl group into the 16-crown-5. The electrodes based on 16-crown-5 derivatives having both a methyl or ethyl group and a benzyloxymethyl group at the pivot carbon (C-15) (3 or 4, see Figure 1) exhibited excellent Na+-selectivity over K+ (log k Na.x = -2.65 and -2.75 for 3 and 4, respectively). |
