Aryl phosphate complexation by cationic cyclodextrins. An enthalpic advantage for guanidinium over ammonium and unusual enthalpy-entropy compensation
Aryl phosphate complexation by cationic cyclodextrins. An enthalpic advantage for guanidinium over ammonium and unusual enthalpy-entropy compensation
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DOI：
10.1021/ol006503r
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发表时间：
2000-11-16
期刊：
影响因子：
5.2
通讯作者：
Smith, PJ
中科院分区：
文献类型：
--
作者：
Hauser, SL;Johanson, EW;Smith, PJ
用阳离子环糊精比较了铵基和胍基与磷酸盐络合的焓和熵。胍宿主结合芳基磷酸具有更有利的焓和更不利的熵，这与胍-磷酸相互作用比铵-磷酸相互作用更强但更有方向性的观点一致。焓熵图的斜率表明，络合作用的发生，在这些系统的顺序上发生了令人惊讶的微小变化。
[GRAPHICS]The enthalpies and entropies for phosphate complexation by ammonium and guanidinium groups have been compared using cationic cyclodextrins. Aryl phosphate binding by guanidinium hosts is associated with more favorable enthalpies and less favorable entropies, consistent with the idea that guanidinium-phosphate interactions are stronger but more directional than ammonium-phosphate interactions. The slope of an enthalpy-entropy plot suggests that complexation occurs with surprisingly small changes in the order of these systems.