Alternating 2,6-/3,5-Substituted Pyridine-Acetylene Macrocycles: π-Stacking Self-Assemblies Enhanced by Intermolecular Dipole–Dipole Interaction

Abstract

Macrocyclic compounds consisting of three 2,6-pyridylene and three 3,5-pyridylene units linked by acetylene bonds were synthesized by a Sonogashira reaction. The X-ray structures showed π-stacked pairs of two macrocycles, in which a 2,6-pyridylene unit of the one molecule overlaps a 3,5-pyridylene of the other molecule because of dipole-dipole interaction. Atomic force microscope (AFM) measurements revealed fibril structures indicating the stacking of the rigid planar macrocycles. Hydrogen-bonding ability of the macrocyclic inside was demonstrated by the addition of octyl β-D-glucopyranoside.

Arylene ethynylene macrocycles: from molecular hosts to components of high-performance supramolecular architectures

“…This was accomplished by Abe, Inouye and coworkers, who incorporated alternating 3,5-and 2,6-pyridylene vertices into an m-AEM hexagon; supplying binding sites for a saccharide guest while overcoming unfavourable local dipole interactions in the cyclization step. 16 In another example from Schlüter et al, terpyridine-containing h-AEM hexagons were found to host three ordered molecules of benzene in their crystal structure. 17 Preparation of AEMs with predesigned binding sites may be taken a step further in the future with incorporation of moieties capable of engaging in dynamic covalent chemistry with target guests.…”

Synthesis and Morphology of a Shape‐Persistent Macrocycle with endo‐Amines and an Inner Tetraethylene Glycol Ether Bridge

“…[2] Based on convenient and efficient synthesis methods together with the rich noncovalent interactions including p-p,V an der Waals forces, hydrogen-bondingi nteraction, and so on, nanostructures with definite structuresh ave been obtained and exhibit typical regular morphologies. [7] Despite the progress described above,h ow to tune the arrangemento ft he building blocks into the desired structures and use the unique properties is still ac hallenge because of the sensitivity of the formed structure to subtle modifications in the backbones, endo-functional groups,o rs ide chains at the exo positions. [3] Upon the decoration of functional groups inside SPMs, inner functional surfaces can be designed, if they can form the ordered structures.…”

“…[3] Upon the decoration of functional groups inside SPMs, inner functional surfaces can be designed, if they can form the ordered structures. [7] Despite the progress described above,h ow to tune the arrangemento ft he building blocks into the desired structures and use the unique properties is still ac hallenge because of the sensitivity of the formed structure to subtle modifications in the backbones, endo-functional groups,o rs ide chains at the exo positions. [4] Schlüter and co-workers,b yi ncorporatingb ipyridine backbones into SPMs, revealed that these macrocycles adopt ad if-ferent layered structure due to slight variation of the side chain.…”

Macrocycle Embrace: Encapsulation of Fluoroarenes by m‐Phenylene Ethynylene Host

“…This rotation allows their bulky COOCEt 3 pendant groups to avoid steric hindrance; in effect, the two macrocycles "embrace" each other, [12] and each one of them includes a 1,4-difluorobenzene guest molecule.…”

“…For example, Flood and co-workers have amply demonstrated [16] that anions can be bound in macrocyclic cavities through the exclusive use of CÀH hydrogen bond donors. In that respect, aza-derivatized analogues of 1 [9,12,17] may sufficiently alter its electronic properties to allow observation of anion binding, perhaps even in solution. Another area of interest is looking at fluorinated arenes too large to fit snugly within the cavity of 1, whether they will instead thread through it, offering a route to a new class of rigid rotaxanes.…”