β-环糊精对聚氧乙烯十二烷基醚的双模式包结作用

Dual Inclusional Modes of β-cyclodextrin with Polyoxyethylene Lauryl Ether

通过表面张力法、浊点法、硫氰酸钴铵显色法和1HNMR研究了β-环糊精(β-CD)对聚氧乙烯十二烷基醚(PL)的包结作用.结果表明,β-CD可与PL形成2∶1和3∶1型两种超分子包结物,表现出不同的物理化学性质.PL的疏水性烷基链被包络进β-CD空腔中,形成了2∶1的超分子包结物;PL的亲水性聚氧乙烯基链被包络进β-CD空腔中,形成了3∶1的超分子包结物.结合实验结果,通过比较β-CD和PL分子的大小,提出了β-CD对PL分子两种可能的包结模式.

Inclusion of β-cyclodextrin （β-CD） with polyoxyethylene lauryl ether （PL） was studied by surface tension, cloud point, color reaction and ^1H NMR measurements. It was established that the inclusion of β-CD with PL affords supramolecular complexes with stoichiometric ratios of 2：1 and 3：1 in aqueous solution. Inclusion complex with the stoichiometry of 2：1 arises from the incorporation of lauryl group of PL into the cavity of β-CD, whereas inclusion complex with the stoichiometry of 3：1 arises from the incorporation of polyoxyethylene group of PL into the cavity of β-CD. A special configuration of the complex has been proposed based on experimental results and molecular sizes.