Designed Synthesis of a Highly Conjugated Hexaethynylbenzene‐Based Host for Supramolecular Architectures

Abstract

The construction of efficient synthetic functional receptors with tunable cavities, and the self-organization of guest molecules within these cavities through noncovalent interactions can be challenging. Here we have prepared a double-cavity molecular cup based on hexaethynylbenzene that possesses a highly π-conjugated interior for the binding of electron-rich guests. X-ray crystallography, NMR spectroscopy, UV/Vis spectroscopy, fluorescent spectroscopy, cyclic voltammetry, and SEM were used to investigate the structures and the binding behaviors. The results indicated that the binding of a guest in one cavity would affect the binding of the same or another guest in the other cavity. The effect of electron transfer in this system suggests ample opportunities for tuning the optical and electronic properties of the molecular cup and the encapsulated guest. The encapsulation of different guests would also lead to different aggregate nanostructures, which is a new way to tune their supramolecular architectures.

An attempt to consider cooperativity in helical-sense preferences induced in fused macrocycles

“…Tris(macrocycle)s 3 are 1,3,5-/2,4,6-differentiated hexakis(phenylethynyl)benzenes (HPEBs) 10 and we started with 1,3,5-trichloro-2,4,6-tris(2-trimethylsilylethynyl)benzene 6 . 11 Stepwise Sonogashira coupling reactions of aryl iodides ( 10 12 and 11 5 ) with desilylated acetylenes on 6 and on the resulting 7 gave trichloro-intermediates 8 .…”

Covalent Organic Helical Cages as Sandwich Compound Containers

“…The presence of three methyl groups on the benzene ring made the oxidative addition between the Pd catalyst and the aryl iodide in the first step of the Sonogashira cross‐coupling reaction less efficient than the analogous step in the synthesis of ( P , P ) 3 ‐ 1a . Deprotection of ( P , P , P )‐ 3b with an excess of KOH in dry toluene at 110 °C gave ( P , P , P )‐ 4b in a moderate 34 % yield, probably due to polymerization side processes. Finally, a dimerization of ( P , P , P )‐ 4b gave ( P , P ) 3 ‐ 1b in 32 % yield by using Breslow's method under pseudo‐high dilution conditions in order to avoid further polymer formation .…”