1068432-30-3

Upstream product

• 1068432-29-0 C₁₇H₁₈N₂O₅ 
• 40751-88-0 2-methoxy-3-nitrobenzoic acid 

Downstream Products

• 1068432-31-4 C₂₅H₂₅N₃O₇ 

Relevant academic research and scientific papers

Persistently folded circular aromatic amide pentamers containing modularly tunable cation-binding cavities with high ion selectivity

In this work, we illustrated a novel design strategy that allows systematically tunable interior properties (effective cavity size, steric crowdedness, and hydrophobicity) contained within a novel class of shape-persistent aromatic pentamers to take place on a scale below 3 A. Such finely tunable structural features are complimented by experimentally observable functional variations in ion-binding potential. Results of the selective, differential binding affinities of three circular pentamers for Li+, Na+, K+, Rb+, and Cs +, substantiated by metal-containing crystal structures and computational modeling, are detailed.

Synthesis, structural investigations, hydrogen-deuterium exchange studies, and molecular modeling of conformationally stablilized aromatic oligoamides

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.

Helical organization in foldable aromatic oligoamides by a continuous hydrogen-bonding network

Introduction of a continuous internal hydrogen-bonding network suppressed the conformational flexibility of a series of oligoaromatic foldamers with a lengthened backbone. The helical ordering over up to six aromatic repeating units was established in solution by a 2D NOESY study and in the solid state by an X-ray diffraction method. Computational molecular modeling further corroborates the experimentally observed helical propagation in this class of foldable molecular strands.

Crystallographic evidence of an unusual, pentagon-shaped folding pattern in a circular aromatic pentamer

(Figure Presented) Introduction of a continuous hydrogen-bonding network suppressed the conformational flexibility of an oligomeric backbone. Cyclization of a rigidified, suitably sized oligomer led to a circular aromatic pentamer. Its crystal structure d