protonated, for anions. The protonation constants of compounds 1–4 have been determined. They are high enough for compounds 1–4 to be fully protonated in a pH-range close to neutrality, as required for binding of anions of weak acids. The effect of structural features on the protonation constants are briefly discussed in relation to the design of macrocyclic polyamine ligands.
分别合成了环尺寸为24、32和27的三种大环
多胺[24] ane-N 6 1,[32] ane-N 8 2和[27] ane-N 6 O 3 3。它们含有
乙二胺单元的三亚
甲基二胺。还制备了作为参考化合物的无环类似物4。化合物1-3是
天然多胺的大环类似物,是
金属阳离子以及质子化阴离子的潜在
配体。已确定化合物1-4的质子化常数。它们足够高以用于化合物1-4根据弱酸阴离子的结合要求,可在接近中性的pH范围内将其完全质子化。关于大环
多胺配体的设计,简要讨论了结构特征对质子化常数的影响。