2554-86-1Relevant academic research and scientific papers
Intramolecularly Hydrogen-Bonded Aromatic Pentamers as Modularly Tunable Macrocyclic Receptors for Selective Recognition of Metal Ions
Liu, Ying,Shen, Jie,Sun, Chang,Ren, Changliang,Zeng, Huaqiang
supporting information, p. 12055 - 12063 (2015/10/05)
Despite the tremendous progress that has been made in macrocyclic chemistry since the discovery of corands, cryptands, and spherands more than four decades ago, macrocyclic systems possessing a high level of controllability in structural configuration con
Synthesis, structural investigations, hydrogen-deuterium exchange studies, and molecular modeling of conformationally stablilized aromatic oligoamides
Yan, Yan,Qin, Bo,Ren, Changliang,Yip, Yeow Kwan,Ye, Ruijuan,Zeng, Huaqiang,Chen, Xiuying,Su, Haibin,Zhang, Dawei
supporting information; experimental part, p. 5869 - 5879 (2010/07/13)
Biasing the conformational preferences of aromatic oligoamides by internally placing intramolecular hydrogen bonds has led to a series of stably folded molecular strands. This article presents the results from extensive solid-state, solution, and computational studies on these folding oligomers. Depending on its backbone length, an oligoamide adopts a crescent or helical conformation. Surprisingly, despite the highly repetitive nature of the backbone, the internally placed, otherwise very similar intramolecular hydrogen bonds showed significantly different stabilities as demonstrated by hydrogen-deuterium exchange data. It was also observed that the hydrogen-bonding strength can be tuned by adjusting the substituents attached to the exterior of the aromatic backbones. Examining the amide hydrogen-deuterium exchange rates of trimers revealed that a six-membered hydrogen bond nearing the ester end is the weakest among all the four intramolecular hydrogen bonds of a molecule. This observation was verified by ab initio quantum mechanical calculations at the level of B3LYP/6-31G. Such a "weak point" creates the "battle of the bulge" where backbone twisting is centered, which is consistently observed in the solid-state structures of the four trimer molecules studied. In the solid state, the oligomers assemble into interesting one-dimensional structures. A pronounced columnar packing of short oligomers (i.e., dimers, trimers, and tetramer) and channel-like, potentially ion-conducting stacks of longer oligomers (i.e., tetramer, pentamer, and hexamer) were observed.
Host-Guest Complexation. 42. Preorganization Strongly Enhances the Tendency of Hemispherands To Form Hemispheraplexes
Doxsee, Kenneth M.,Feigel, Martin,Stewart, Kent D.,Canary, Jimmy W.,Knobler, Carolyn B.,Cram, Donald J.
, p. 3098 - 3107 (2007/10/02)
The desing and syntheses of four new macrocyclic host compounds (1-4, Chart I) are reported which contain three cyclic urea carbonyls and two anisyl-like oxygens alternately arranged to bind alkali metal or alkylammonium ion guests.The macroring systems a
