二氯代乙酰基二苯并-14-冠-4的合成及对锂、钠的萃取研究

Synthesis bichloro acetyl dibenzo-14-crown-4 and extractions for lithium and sodium

以多聚磷酸为催化剂和反应溶剂,氯乙酸为酰化剂,对二苯并-14-冠-4进行了酰化,合成了标题化合物,并进行了表征,确认组成。与二苯并-14-冠-4对照,比较了在不同pH的条件下标题化合物萃取锂、钠的情况。结果表明,标题化合物和二苯并-14-冠-4对锂的配合比都是1∶1,并都随着萃取体系pH的增大而增大,到达一定值(前者为96.8%,后者为99.89%)后趋于稳定,但是标题化合物对锂的萃取受pH的影响要比二苯并14-冠-4显著;同时它们对钠的萃取能力较差(前者最大为6.58%,后者最大为3.68%)。由此可见,标题化合物对锂的萃取更易受pH控制。该研究为冠醚在更广领域的应用提供了基础性材料。

Bichloro acetyl dibenzo-14-crown-4 which has never been reported before and it is synthesized by acylating dibenzo-14-crown-4 when polyphosphoric acid works as both catalyst and solvent and chloroacetic acid as an acylating agent. Its composition and structural substitution are characterized. Lithium extraction of bichloro acetyl dibenzo-14-crown-4 is conducted in the presence of sodium at different pH in parallel of dibenzo-14-crown-4 for comparison. Results show that both bichloro acetyl dibenzo-14-crown-4 and dibenzo-14-crown-4 coordinate lithium in 1：1 ratio and their lithium extractions increase as pH goes higher,leveling off at a certain pH values （extraction efficiency for the former 96.8% , the later 99.89% ）. However, bichloro acetyl dibenzo-14-crown-4 is more sensitive to pH than dibenzo-14-crown-4 in terms of lithium extraction. Both of them demonstrate poor extraction efficiency for sodium （the former is 6.58% in max. ,the later is 3.68% ） ,revealing bichloro acetyl dibenzo-14-crown-4 with an excellent selectivity for lithium. The work provides a new basic chemical for the crown ether family used in a broader field.