An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two...An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two opposite orientations, i.e. the amine group of α-aminopyridine pointing to the primary side (1a, occupancy: 41.2%) or the secondary side (1b, occupancy: 58.8%) of β-cyclodextrin, forming two scalelike supramolecular aggregations. The studies of 2D NMR and circular dichroism spectra indicated that the α-aminopyridine molecule is deeply embedded in the β-cyclodextrin cavity to form host-guest inclusion complex, showing a circular dichroism spectrum induced by the chiral cavity of cyclodextrin. The results obtained are helpful for understanding the molecular recognition and aggregation mechanism between the host and guest.展开更多
The self-assembly behavior of mono(6-phenolic-6-deoxy)-β-cyclodextrin bothin solution and the solid state is comparatively studied by X-ray crystallography and ~1H NMRspectroscopy. The results obtained show that the ...The self-assembly behavior of mono(6-phenolic-6-deoxy)-β-cyclodextrin bothin solution and the solid state is comparatively studied by X-ray crystallography and ~1H NMRspectroscopy. The results obtained show that the phenolic groups in the crystal 1 can successivelypenetrate into the adjacent β-cyclodextrin cavities from the secondary side to form head-to-taillinear polymeric su-pramolecule with a 2-fold screw axis. The self-assembly behavior also can bedetermined in D_2O solution, giving a self-association constant of 240 mol^(-1)·L. Using thepresent and previous structures reported for the relevant β-cyclodextrin derivatives, i.e.,mono(6-anilino-6-deoxy)-β-cyclodextrin, mono(6-phenylselenyl-6-deoxy)-β-cyclodextrin, andmono(6-phenylthio-6-deoxy)-β-cyclodextrin, we further reveal the factors governing the formationsof supramolecular assemblies.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 20272028 and 90306009).
文摘An inclusion complex (1) has been prepared by β-cyclodextrin with α-aminopyridine. The result of X-ray crystallographic analyses showed that the α-aminopyridine molecules in the β-cyclodextrin cavities possess two opposite orientations, i.e. the amine group of α-aminopyridine pointing to the primary side (1a, occupancy: 41.2%) or the secondary side (1b, occupancy: 58.8%) of β-cyclodextrin, forming two scalelike supramolecular aggregations. The studies of 2D NMR and circular dichroism spectra indicated that the α-aminopyridine molecule is deeply embedded in the β-cyclodextrin cavity to form host-guest inclusion complex, showing a circular dichroism spectrum induced by the chiral cavity of cyclodextrin. The results obtained are helpful for understanding the molecular recognition and aggregation mechanism between the host and guest.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos.90306009, 20272028, and 20421202) the Tianjin Natural Science Foundation (Grant No. 043604411).
文摘The self-assembly behavior of mono(6-phenolic-6-deoxy)-β-cyclodextrin bothin solution and the solid state is comparatively studied by X-ray crystallography and ~1H NMRspectroscopy. The results obtained show that the phenolic groups in the crystal 1 can successivelypenetrate into the adjacent β-cyclodextrin cavities from the secondary side to form head-to-taillinear polymeric su-pramolecule with a 2-fold screw axis. The self-assembly behavior also can bedetermined in D_2O solution, giving a self-association constant of 240 mol^(-1)·L. Using thepresent and previous structures reported for the relevant β-cyclodextrin derivatives, i.e.,mono(6-anilino-6-deoxy)-β-cyclodextrin, mono(6-phenylselenyl-6-deoxy)-β-cyclodextrin, andmono(6-phenylthio-6-deoxy)-β-cyclodextrin, we further reveal the factors governing the formationsof supramolecular assemblies.
