Facile separation of cinnamyl acetate and cinnamaldehyde based on host-guest complexation with β-cyclodextrin
Facile separation of cinnamyl acetate and cinnamaldehyde based on host-guest complexation with β-cyclodextrin
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基于β-环糊精的主客体络合轻松分离乙酸肉桂酯和肉桂醛
DOI：
10.1002/ffj.3443
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发表时间：
2018
影响因子：
2.6
通讯作者：
Ji Hongbing
中科院分区：
文献类型：
--
作者：
Chai Kungang;Xu Zhijun;Zheng Lu;Zhou Liqin;Tong Zhangfa;Ji Hongbing
在水溶液中，乙酸肉桂酯（CAc）和肉桂醛（CA）与β-环糊精（β-CD）的包合反应中，观察到了CAc的选择性包合。为了证明β-CD在分离CAc和CA中的潜在应用，从构象和热力学角度研究了β-CD对CAc相对于CA的优先亲和力。通过1H和2D（XRD）进行的络合几何形状的测定证实了β-CD空腔对CAc和CA的包合能力。通过紫外-可见（UV-Vis）光谱测定的稳定常数和等温滴定微量热法测定的热力学参数发现，与CA相比，疏水和氢键相互作用共同促进CAc形成更稳定的β-CD结合复合物，其化学计量比为1：1。此外，从结合能和包合几何学的角度，从理论上研究了β-CD对CAc（相对于CA）的更高结合亲和力。在β-CD水溶液中，等摩尔的CAc-CA混合物通过包合络合实现分离。考察了溶剂极性、主客体摩尔比等实验条件对分离性能的影响。在优化条件下，选择性包合过程显示出3.5的CAc/CA分离因子，其在5个循环后保持稳定，表明β-CD是一种高度可重复使用的主体材料。
A selective inclusion of cinnamyl acetate (CAc) is observed during the complexation of CAc and cinnamaldehyde (CA) with β‐cyclodextrin (β‐CD) in aqueous solution. To demonstrate the potential application of β‐CD for the separation of CAc and CA, the preferential affinity of β‐CD for CAc over CA was studied from conformational and thermodynamic points of view. Determination of the complexation geometries, performed by 1H and 2D (XRD), confirmed the inclusion capacity of the β‐CD cavity for CAc and CA. From the stability constants measured by ultraviolet‐visible (UV–Vis) spectroscopy and thermodynamic parameters measured by isothermal titration microcalorimetry, it was found that compared to CA, hydrophobic and hydrogen bonding interactions jointly promote CAc to form a more stable β‐CD binding complex with 1:1 stoichiometry. Furthermore, the higher binding affinity of β‐CD for CAc (over CA) was investigated theoretically in terms of binding energy and inclusion geometries. The separation of the equimolar CAc–CA mixture was achieved by inclusion complexation in β‐CD aqueous solution. The effects of the experimental conditions, such as the polarity of the solvent and guest/host molar ratio, on separation performance were investigated. Under the optimized conditions, the selective inclusion procedure exhibited a CAc/CA separation factor of 3.5, which remained stable after five cycles, indicating that β‐CD is a highly reusable host material.