Contrasting pKa Shifts in Cucurbit[7]uril Host-Guest Complexes Governed by an Interplay of Hydrophobic Effects and Electrostatic Interactions
Contrasting pKa Shifts in Cucurbit[7]uril Host-Guest Complexes Governed by an Interplay of Hydrophobic Effects and Electrostatic Interactions
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DOI：
10.1021/acsomega.6b00427
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发表时间：
2017-01-01
期刊：
影响因子：
4.1
通讯作者：
Pina, Fernando
中科院分区：
文献类型：
--
作者：
Basilio, Nuno;Gago, Sandra;Pina, Fernando
瓜环[7]与带有二甲氨基的客体的包合物显示出预期的pK（a）向上移动，而它们的二乙氨基对应物显示出pK（a）的降低，这是由于未质子化形式的优先稳定化。这些结果确定的二乙基氨基基团作为取代基的选择，以避免受体辅助的客体分子的质子化，并提出了新的证据的作用，在葫芦脲络合的驱动力的疏水效应。
Cucurbit[7]uril inclusion complexes with guests bearing dimethylamino groups show the expected upward pK(a) shifts, whereas their diethylamino counterparts display a decrease in pK(a) due to the preferential stabilization of the unprotonated form. These results identify the diethylamino group as the substituent of choice to avoid receptor-assisted protonation of guest molecules and present new evidence for the role of the hydrophobic effect as a driving force in cucurbituril complexation.