共查询到20条相似文献,搜索用时 0 毫秒
1.
Dr. Semin Lee Dr. Brandon E. Hirsch Yun Liu James R. Dobscha David W. Burke Dr. Steven L. Tait Dr. Amar H. Flood 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):560-569
Programming the synthesis and self‐assembly of molecules is a compelling strategy for the bottom‐up fabrication of ordered materials. To this end, shape‐persistent macrocycles were designed with alternating carbazoles and triazoles to program a one‐pot synthesis and to bind large anions. The macrocycles bind anions that were once considered too weak to be coordinated, such as PF6?, with surprisingly high affinities (β2=1011 M ?2 in 80:20 chloroform/methanol) and positive cooperativity, α=(4 K2/K1)=1200. We also discovered that the macrocycles assemble into ultrathin films of hierarchically ordered tubes on graphite surfaces. The remarkable surface‐templated self‐assembly properties, as was observed by using scanning tunneling microscopy, are attributed to the complementary pairing of alternating triazoles and carbazoles inscribed into both the co‐facial and edge‐sharing seams that exist between shape‐persistent macrocycles. The multilayer assembly is also consistent with the high degree of molecular self‐association observed in solution, with self‐association constants of K=300 000 M ?1 (chloroform/methanol 80:20). Scanning tunneling microscopy data also showed that surface assemblies readily sequester iodide anions from solution, modulating their assembly. This multifunctional macrocycle provides a foundation for materials composed of hierarchically organized and nanotubular self‐assemblies. 相似文献
2.
3.
Inside Cover: Supramolecular Engineering of Oligothiophene Nanorods without Insulators: Hierarchical Association of Rosettes and Photovoltaic Properties (Chem. Eur. J. 49/2014) 下载免费PDF全文
Prof. Dr. Shiki Yagai Mika Suzuki Dr. Xu Lin Marina Gushiken Takuya Noguchi Prof. Dr. Takashi Karatsu Prof. Dr. Akihide Kitamura Prof. Dr. Akinori Saeki Prof. Dr. Shu Seki Dr. Yoshihiro Kikkawa Yuki Tani Prof. Dr. Ken‐ichi Nakayama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16010-16010
4.
5.
6.
7.
8.
9.
10.
Inside Back Cover: Control over Nanostructures and Associated Mesomorphic Properties of Doped Self‐Assembled Triarylamine Liquid Crystals (Chem. Eur. J. 5/2015) 下载免费PDF全文
Dr. Yuya Domoto Dr. Eric Busseron Prof. Dr. Mounir Maaloum Dr. Emilie Moulin Prof. Dr. Nicolas Giuseppone 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(5):2271-2271
11.
12.
Ignacio Alfonso Dr. Miriam Bru Dr. M. Isabel Burguete Dr. Eduardo García‐Verdugo Dr. Santiago V. Luis Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(4):1246-1255
The self‐assembling abilities of several pseudopeptidic macrocycles have been thoroughly studied both in the solid (SEM, TEM, FTIR) and in solution (NMR, UV, CD, FTIR) states. Detailed microscopy revealed large differences in the morphology of the self‐assembling micro/nanostructures depending on the macrocyclic chemical structures. Self‐assembly was triggered by the presence of additional methylene groups or by changing from para to meta geometry of the aromatic phenylene backbone moiety. More interestingly, the nature of the side chain also plays a fundamental role in some of the obtained nanostructures, thus producing structures from long fibers to hollow spheres. These nanostructures were obtained in different solvents and on different surfaces, thus implying that the chemical information for the self‐assembly is contained in the molecular structure. Dilution NMR studies (chemical shift and self‐diffusion rates) suggest the formation of incipient aggregates in solution by a combination of hydrogen‐bonding and π–π interactions, thus implicating amide and aryl groups, respectively. Electronic spectroscopy further supports the π–π interactions because the compounds that lead to fibers show large hypochromic shifts in the UV spectra. Moreover, the fiber‐forming macrocycles also showed a more intense CD signature. The hydrogen‐bonding interactions within the nanostructures were also characterized by attenuated total‐reflectance FTIR spectroscopy, which allowed us to monitor the complete transition from the solution to the dried nanostructure. Overall, we concluded that the self‐assembly of this family of pseudopeptidic macrocycles is dictated by a synergic action of hydrogen‐bonding and π–π interactions. The feasibility and geometrical disposition of these interactions finally render a hierarchical organization, which has been rationalized with a proposal of a model. The understanding of the process at the molecular level has allowed us to prepare hybrid soft materials. 相似文献
13.
14.
15.
16.
17.
18.
19.