三种瓜环与苯并吲唑衍生物的超分子自组装

Self-Assembly Modes of Three Cucurbit[n]urils with Benzoindazole Derivative

设计、合成了医药中间体3-吡啶基苯并吲唑衍生物(DIHY)作为客体分子,并利用~1H NMR、质谱、等温量热滴定和紫外吸收光谱法考察了主体对称四甲基六元瓜环(TMeQ[6])、七元瓜环(Q[7])以及八元瓜环(Q[8])和与其相互作用的结构特征.结果表明,这三种具有不同空腔大小的瓜环与DIHY之间具有不同的作用模式.TMe Q[6]-DIHY体系中,客体分子位于瓜环的端口处; Q[7]-DIHY体系中,客体分子DIHY的4,5-二氢-2H-苯并吲唑部分进入到瓜环的空腔内部,而吡啶基团位于瓜环的端口形成1∶1的类轮烷结构; Q[8]-DIHY体系中, 2个客体分子DIHY的4,5-二氢-2H-苯并吲唑部分以"面对面"的堆叠方式进入到Q[8]的空腔中,而吡啶基团位于瓜环的端口,自组装形成1∶2的超分子结构.

A pharmaceutical intermediate,3-pyridyl benzoxazole derivatives(DIHY),was designed and synthesized as the guest molecule.The self-assembly binding models of tetramethyl cucurbit[6]uril(TMeQ[6]),cucurbit[7]uril(Q[7]) and cucurbit[8]uril(Q[8]) with DIHY were investigated by 1 H NMR,MS,isothermal titration calorimetry and UV-Vis spectrum.The results showed that there are different modes of interaction between these three different cucurbit[n]uril and DIHY.For the TMeQ[6]-DIHY system,the guest molecule is located at the port of the TMeQ[6],while for the Q[7]-DIHY system,the 4,5-dihydro-2 H-benzoxazole moiety of the guest molecule reside within the cavity of Q[7] host,whereas the pyridyl group of DIHY guest remains outside of the portal to form the 1∶1 inclusion complexes of pseudorotaxane structure.Nevertheless,the 4,5-dihydro-2 H-benzoxazole moiety of two guest molecule is included in the cavity of Q[8] host in a "face to face" stacking way,while the pyridine group of DIHY is located at the port of Q[8] to form a 1∶2 supramolecular structure.