三氯酚與環糊精之結合常數研究

Determination of Formation Constants for β-Cyclodextrin Complexes of Trichlorophenols

薛仲娟(Chung-Chuan Hsueh)

《宜蘭技術學報》 9期工學專輯 (2002/12) Pp. 283-292

https://doi.org/10.6179/nit.bce.2002.09.34

摘要

以紫外光光譜法決定5種三氯酚（2,3,4-、2,3,5-、2,3,6-、2,4,5-及2,4,6-三氯酚）之結構異構物與β-環糊精形成內包錯合物之結合常數Kf。三氯酚與β-環糊精作用除了依三氯酚的形狀大小與β-環糊精孔洞適合性及疏水性作用力外，二者之間尚有氫鍵作用力，是以此五種三氯酚與β-環糊精有不同程度的結合力。當β-環糊精濃度增加時，其中2,3,5-及2,4,6-三氯酚與β-環糊精形成內包錯合物之λmax為紅位移（red shift），其餘三種三氯酚（2,3,4-、2,3,6-及2,4,5-)呈藍位移（blue shift），且此五種三氯酚之內包錯合物在λmax 吸收度皆呈hyperchromic。三氯酚為有機酸，在高pH時會解離成多氯酚陰離子，所以不同pH時，三氯酚若為中性分子時與β-環糊精之Kf，比為陰離子時大。若三氯酚上之羥基若被氯阻擋者，其Kf較小如2,3,6-及2,4,6-三氯酚者，三氯酚之Kf最大為2,4,5-三氯酚者。

關鍵字

紫外光光譜法 ； 三氯酚 ； β-環糊精 ； 結合常數

並列摘要

The formation constants of five trichlorophenols (2,3,4-、2,3,5-、2,3,6-、2,4,5-及2,4,6-trichlorophenol) β-cyclodextrin (β-CD) complexes were determined by ultraviolet-visible (UV-VIS) spectroscopic method. Three chloro substituents of these trichlorophenols were different displacements on phenol, their structure would influence the interaction and the formation constants of inclusion complexes between trichlorophenols and β-CD. The interactions of inclusion complexes were included hydrophobic interaction and hydrogen bonding. The λmax of inclusion complexes of 2,3,5- and 2,4,6-trichlorophenol with β-CD were red shift, the other were blue shift. Nevertheless, the absorbance of the five trichlorophenols at λmax were all hyperchromic, as β-CD concentration were increased. If the weak acid trichlorophenols were anion, the formation constants of their inclusion complexes were less than the neutral forms'. If the hydroxy of trichlorophenol were more hindered, the formation constants of their inclusion complexes were less. The formation constant of 2,4,5-trichlorophenol were maximum in all.

並列關鍵字

trichlorophenol ； β-cyclodextrin ； formation constant ； ultraviolet-visible (UV-VIS) spectroscopic method