A new approach was employed for the synthesis of mono- and A1/A2-dihydroxy-functionalized pillar[5]arenes by the removal of the pillar[5]arene-bearing benzyl group(s) using catalytic hydrogenation. Host–guest complexation between a mono-hydroxy-pillar[5]arene with long-chain alkyl alcohol guests was studied. The encapsulation characteristics of the pillar[5]arene was affected by the presence of a hydroxy group, resulting in the formation of a 1 : 2 complex with long-chain alkyl alcohols in solution and in the solid state. For comparison, analog experiments were conducted with permethylated pillar[5]arene (DMP5) and long-chain alkyl alcohol guests. The complexation experiments revealed that the absence of a hydroxyl group on the pillar[5]arene frame resulted in the formation of a 1 : 1 complex. The formed complexes were confirmed by proton nuclear magnetic resonance spectroscopy and single-crystal X-ray analysis.

中文翻译：

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单和A1 / A2-二羟基取代的支柱[5]芳烃的合成及其与烷基醇在溶液和固态中的络合的新方法

一种新的方法被用来合成单和A1 / A2-二羟基官能化的支柱[5]芳烃，通过催化加氢除去带有支柱[5]芳烃的苄基。研究了单羟基[5]芳烃与长链烷基醇客体之间的主客体络合。支柱[5]芳烃的封装特性受羟基的存在影响，导致与长链烷基醇在溶液中和固态形成1：2的络合物。为了进行比较，对全甲基化的支柱[5]芳烃（DMP5）和长链烷基醇客体进行了模拟实验。络合实验表明，在柱[5]芳烃骨架上不存在羟基导致形成1：1络合物。