大环硫杂冠醚的合成及对Ag(Ⅰ)和Tl(Ⅰ)的选择性萃取

基于冠醚配位化学和软硬酸碱理论, 设计合成了2种预期对Ag(Ⅰ)和Tl(Ⅰ)具有较强配位能力的超大环冠醚10,19-二硫杂苯并30-冠-10(DHB30C10)和10,13,17,20-四硫杂苯并31-冠-10(THB31C10). 采用溶剂萃取法考察了2种冠醚对Ag(Ⅰ)和Tl(Ⅰ)的选择萃取性能. 结果表明, 在单一体系中, DHB30C10和THB31C10对Ag(Ⅰ)的络合常数分别为9.76和13.40, 对Tl(Ⅰ)的络合常数分别为4.769和4.325. 在多元体系中, 2种冠醚对Ag(Ⅰ)均具有较强选择性, 其中DHB30C10对Cu(Ⅱ)和Ni(Ⅱ)的分离系数可达194.68和142.44, THB31C10对Cu(Ⅱ)和Ni(Ⅱ)的分离系数可达172.81和268.53, 但对Tl(Ⅰ)几乎不具有选择性. 并探讨分析了DHB30C10与THB31C10对Ag(Ⅰ)和Tl(Ⅰ)的萃取机理.

Synthesis of Macrocyclic Thiacrown Ethers and Their Selective Extraction for Ag(Ⅰ) and Tl(Ⅰ) ?

Based on the crown ether coordination chemistry and soft and hard acid-base(HSAB) theory, two macrocyclic crown ethers of 10,19-dithiabenzo-30-crown-10(DHB30C10) and 10,13,17,20-tetrathiabenzo-3-crown-10(THB31C10) were synthesized, which potentially have excellent complex ability with Ag(Ⅰ) and Tl(Ⅰ). The extraction abilities of the two crown ethers for Ag(Ⅰ) and Tl(Ⅰ) were investigated. The results showed that in the single system, the complexing constants of DHB30C10 and THB31C10 for Ag(Ⅰ) were 9.76 and 13.40, and for Tl(Ⅰ) were 4.769 and 4.35, respectively. In the multi-system, the two crown ethers both exhibit strong selectivity to Ag(Ⅰ). The separation coefficients of DHB30C10 for Ag(Ⅰ) to Cu(Ⅱ) and Ni(Ⅱ) were 194.68 and 142.44, and the corresponding data of THB31C10 were 172.81 and 268.53, respectively. However, the two crown ethers showed poor selectivity to Tl(Ⅰ). The extraction mechanisms of DHB30C10 and THB31C10 for Ag(Ⅰ) and Tl(Ⅰ) were analyzed.