High‐Fidelity Multistate Switching with Anion–Anion and Acid–Anion Dimers of Organophosphates in Cyanostar Complexes

Abstract

The acid-base switching of complexes formed from anti-electrostatic anion-anion homodimers of organophosphates and cyanostar macrocycles was investigated for the first time. High-fidelity 2:2 complexes were selected by using suitably sized organo substituents. Reversible and direct switching occurs with triflic acid and hydroxide base. An unexpected acid⋅⋅⋅anion heterodimer was discovered with weaker picric acid, which helped reveal some of the elementary steps. Switching can also proceed in a cooperative (strong anion then weak acid) or stepwise manner (weak acid then strong anion).

Phosphate–phosphate oligomerization drives higher order co-assemblies with stacks of cyanostar macrocycles

“… 20 Previous work in this laboratory used a naphthyl-substituted phosphate to direct formation of 2 : 2 complexes with cyanostar involving a phosphate dimer. 43 These results suggest that phosphate oligomerizes when it has the steric freedom to do so, and the extent of oligomerization can be circumscribed by the size and shape of the receptor's cavity.…”

Cations brought together by hydrogen bonds: the protonated pyridine–boronic acid dimer explained

“…[15][16][17][18][19] In addition, other authors have reported computational studies on the stability of other complexes formed, thanks to hydrogen-bonding interactions. [20][21][22][23] From the experimental point of view, the detection of these cation-cation and anion-anion complexes in the gas phase has remained elusive, unless they are stabilized by receptors that can accommodate such dimeric species through noncovalent interactions, as reported for sulfamic acid clusters, 24 bisulphate dimers, 25 organophosphate dimers, 26 phosphate dimers 27 and oligomers, 28,29 and pyrophosphate dimers. 28 Very recently, halogen bonding interactions have also been the subject of theoretical studies of ion like-charge interactions in both dianionic [30][31][32] and dicationic complexes.…”

Host–Host Interactions Control Self‐assembly and Switching of Triple and Double Decker Stacks of Tricarbazole Macrocycles Co‐assembled with anti‐Electrostatic Bisulfate Dimers

“…[14] These dimers are stabilizedi ns olution when co-assembled with ah ost, [15] for example, cyanostar macrocycles. [14,16] Yett hese macrocycles do not work alone. They stack together as ap airo rt rimer,w hich suggests an ew way to enhance stabilitya nd direct structure with host-host contacts.…”

“…They stack together as ap airo rt rimer,w hich suggests an ew way to enhance stabilitya nd direct structure with host-host contacts. However,s uch host-host interactions involving cyanostars are not strong enough to control co-assembly, as evidenced by the formation of mixtures [14,16] of products.T oe xplore this novel idea fully for the first time, we employ an ew class of macrocycle, the tricarbazole triazolophane, [17] aka tricarb (TC, Figure 1b-d). This macrocycle has similara nion recognition to cyanostar but it displays strongers elf-association [17a] from favorable electrostatic interactions (dipole-dipole coupling) between p faces (Figure 1c and d).…”