Anion-Directed Self-Assembly of Coordination Polymer into Tunable Secondary Structure
摘要:
A bent-shaped bipyridine ligand containing a dendritic aliphatic side chain has been synthesized as a ligand and complexed with silver ion through a self-assembling process. The resulting complexes were observed to self-assemble into supramolecular structures that differ significantly as a function of the counteranion size in the solid state, as confirmed by 1-D and 2-D X-ray diffraction experiments. The secondary structure of a cationic coordination chain appears to be dependent on the size of the counteranion. As the size of anion increases, the secondary structure of the coordination chain changes, from a helical chain, via a dimeric cycle, to a zigzag chain in the solid state. Interestingly, dilute solutions of the complexes exhibiting a columnar structure in polar solvents undergo spontaneous gelation and the resulting gels display a significant Cotton effect in the chromophore of the aromatic unit. These results represent a significant example that small variation in the anion size can provide a useful strategy to manipulate the secondary structure of linear chain and thereby solid-state supramolecular structure.
Anion-Directed Self-Assembly of Coordination Polymer into Tunable Secondary Structure
摘要:
A bent-shaped bipyridine ligand containing a dendritic aliphatic side chain has been synthesized as a ligand and complexed with silver ion through a self-assembling process. The resulting complexes were observed to self-assemble into supramolecular structures that differ significantly as a function of the counteranion size in the solid state, as confirmed by 1-D and 2-D X-ray diffraction experiments. The secondary structure of a cationic coordination chain appears to be dependent on the size of the counteranion. As the size of anion increases, the secondary structure of the coordination chain changes, from a helical chain, via a dimeric cycle, to a zigzag chain in the solid state. Interestingly, dilute solutions of the complexes exhibiting a columnar structure in polar solvents undergo spontaneous gelation and the resulting gels display a significant Cotton effect in the chromophore of the aromatic unit. These results represent a significant example that small variation in the anion size can provide a useful strategy to manipulate the secondary structure of linear chain and thereby solid-state supramolecular structure.
Reversible Transformation of Helical Coils and Straight Rods in Cylindrical Assembly of Elliptical Macrocycles
作者:Jung-Keun Kim、Eunji Lee、Min-Cheol Kim、Eunji Sim、Myongsoo Lee
DOI:10.1021/ja907462h
日期:2009.12.16
We have demonstrated that, as the molecular length of elliptical macrocycle is increased, the self-assembled structure changes from spherical micelles to helical coils and finally to monolayered vesicles, in the order of decreasing interfacial curvature. Notably, the helical coils reversibly transform into straight rods upon heating while maintaining the supramolecular chirality. This structural transition
Static and Dynamic Nanosheets from Selective Assembly of Geometric Macrocycle Isomers
作者:Yanqiu Wang、Yongju Kim、Myongsoo Lee
DOI:10.1002/anie.201607143
日期:2016.10.10
stimulation by a thermal signal. Furthermore, the mixed solution of the twoisomers exhibits self‐sorting behavior, generating the coexistence of the two independent self‐assembled structures, the planar sheets and the folded scrolls. The self‐sorted supramolecular objects with considerable shape and size differences are able to be readily separated, one isomer from the other.
Guest-Driven Inflation of Self-Assembled Nanofibers through Hollow Channel Formation
作者:Yanqiu Wang、Zhegang Huang、Yongju Kim、Ying He、Myongsoo Lee
DOI:10.1021/ja510182x
日期:2014.11.19
form thin nanofibers with pyridine-functionalized aromatic cores. Notably, the nanofibers reversibly inflate into helical tubules through the formation of hollow cavities triggered by p-phenylphenol, a hydrogen-bonding guest. The reversible inflation of the nanofibers arises from the packing rearrangements in the aromatic cores from transoid dimers to cisoid macrocycles driven by the reversible hydrogen-bonding
Aqueous nanofibers with switchable chirality formed of self-assembled dumbbell-shaped rod amphiphiles
作者:Zhegang Huang、Eunji Lee、Ho-Joong Kim、Myongsoo Lee
DOI:10.1039/b913286d
日期:——
We have demonstrated that fibrillar aggregates formed from the self-assembly of a dumbbell-shaped rod amphiphile undergo a reversible chiral–non-chiral transition triggered by temperature.
我们已经证明,哑铃形棒状两亲分子自组装形成的纤维状聚集体会经历由温度触发的可逆的手性-非手性转变。
Spontaneous Chirality Induction in the Assembly of a Single Layer 2D Network with Switchable Pores
作者:Bowen Shen、Chunyu Pan、Xiaopeng Feng、Jehan Kim、Mo Sun、Myongsoo Lee
DOI:10.1002/anie.202300658
日期:——
Singlelayerchiral2Dnetwork structures with photoswitchable internal cavities have been formed by the self-assembly of azobenzene-based tetrapod aromatic amphiphiles, with spontaneouschiralityinduction arising from the breaking of both the plane of symmetry and inversion symmetry. The chiralnetwork structures can selectively catch one enantiomer from a racemic solution and then release it upon