Novel lariat ethers with pendent N-alkyl- and
N-aryl-sulfonyl carbamoyl groups are synthesized in two steps
from sym-(decyl)dibenzo-16-crown-5-oxyacetic acid; for
competitive solvent extraction of alkali metal cations from aqueous
solutions into chloroform by these proton-ionizable lariat ethers with
‘tunable’ acidity, the selectivity order is
Na
+
>>K
+
with no detectable extraction of
Li
+
, Rb
+
or Cs
+
.
这些具有 "可调 "酸度的可质子离子化的拉枝醚可将碱
金属阳离子从
水溶液中竞争性地萃取到
氯仿中,其选择性顺序为 Na + >>K +,而对 Li +、Rb + 或 Cs + 的萃取则无法检测到。