Puttreddy Rakesh, Beyeh Ngong Kodiah, Ras Robin H A, Rissanen Kari
University of Jyvaskyla Department of Chemistry Nano Science Center PO Box 3540014 Jyvaskyla Finland.
Aalto University School of Science Department of Applied Physics Puumiehenkuja 2FIN-02150 Espoo Finland.
ChemistryOpen. 2017 Apr 4;6(3):417-423. doi: 10.1002/open.201700026. eCollection 2017 Jun.
The C-ethyl-2-methylresorcinarene () forms 1:1 in-cavity complexes with aromatic ,-dioxides, only if each of the aromatic rings has an N-O group. The structurally different C-shaped 2,2'-bipyridine ,'-dioxide (2,2'-BiPyNO) and the linear rod-shaped 4,4'-bipyridine ,'-dioxide (4,4'-BiPyNO) both form 1:1 in-cavity complexes with the host resorcinarene in crown and conformations, respectively. In the solid state, the host-guest interactions between the 1,3-bis(4-pyridyl)propane ,'-dioxide (BiPyPNO) and the host stabilize the unfavorable - conformation. Contrary to the ,'-dioxide guests, the mono-oxide guest, 4-phenylpyridine -oxide (4PhPyNO), does not form an in-cavity complex in the solid state. The host-guest complexation and the relative guest affinities were studied through H NMR competition experiments in methanol. Single-crystal X-ray crystallography of the 1:1 complexes supports the proposed solution-state structures, also revealing strong hydrogen bonds between the host and the guests, not observed in solution owing to hydrogen/deuterium (H/D) exchange processes in methanol.
只有当每个芳环都含有一个N - O基团时，C - 乙基 - 2 - 甲基间苯二酚芳烃（）才会与芳族α,β - 二氧化物形成1:1的腔内配合物。结构不同的C形2,2'-联吡啶α,β - 二氧化物（2,2'-BiPyNO）和线性棒状4,4'-联吡啶α,β - 二氧化物（4,4'-BiPyNO）分别与主体间苯二酚芳烃在冠醚和构象中形成1:1的腔内配合物。在固态下，1,3 - 双（4 - 吡啶基）丙烷α,β - 二氧化物（BiPyPNO）与主体之间的主客体相互作用稳定了不利的构象。与α,β - 二氧化物客体相反，单氧化物客体4 - 苯基吡啶α - 氧化物（4PhPyNO）在固态下不形成腔内配合物。通过在甲醇中的1H NMR竞争实验研究了主客体络合作用和相对客体亲和力。1:1配合物的单晶X射线晶体学支持了所提出的溶液态结构，同时也揭示了主体与客体之间强烈的氢键，由于甲醇中的氢/氘（H/D）交换过程，在溶液中未观察到这种氢键。
