Steric Control over the Threading of Pyrophosphonates with One or Two Cyanostar Macrocycles during Pseudorotaxane Formation.

The supramolecular recognition of anions is increasingly harnessed to achieve the self-assembly of supramolecular architectures, ranging from cages and polymers to (pseudo)rotaxanes. The cyanostar (CS) macrocycle has previously been shown to form 2 : 1 complexes with organophosphate anions that can be turned into [3]rotaxanes by stoppering. Here we achieved steric control over the assembly of pseudorotaxanes comprising the cyanostar macrocycle and a thread that is based, for the first time, on organo-pyrophosphonates.

Orthogonal, modular anion-cation and cation-anion self-assembly using pre-programmed anion binding sites.

Subcomponent self-assembly relies on cation coordination whereas the roles of anions often only emerge during the assembly process. When sites for anions are instead pre-programmed, they have the potential to be used as orthogonal elements to build up structure in a predictable and modular way. We explore this idea by combining cation (M) and anion (X) binding sites together and show the orthogonal and modular build up of structure in a multi-ion assembly.

Corrigendum: Rigidity and Flexibility in Rotaxanes and Their Relatives; On Being Stubborn and Easy-Going.

[This corrects the article DOI: 10.3389/fchem.2022.

Rigidity and Flexibility in Rotaxanes and Their Relatives; On Being Stubborn and Easy-Going.

Rotaxanes are an emerging class of molecules composed of two building blocks: macrocycles and threads. Rotaxanes, and their pseudorotaxane and polyrotaxane relatives, serve as prototypes for molecular-level switches and machines and as components in materials like elastic polymers and 3D printing inks. The rigidity and flexibility of these molecules is a characteristic feature of their design.

Chain Entropy Beats Hydrogen Bonds to Unfold and Thread Dialcohol Phosphates inside Cyanostar Macrocycles To Form [3]Pseudorotaxanes.

The recognition of substituted phosphates underpins many processes including DNA binding, enantioselective catalysis, and recently template-directed rotaxane synthesis. Beyond ATP and a few commercial substrates, however, little is known about how substituents effect organophosphate recognition. Here, we examined alcohol substituents and their impact on recognition by cyanostar macrocycles.

Sequence-Defined Macrocycles for Understanding and Controlling the Build-up of Hierarchical Order in Self-Assembled 2D Arrays.

Anfinsen's dogma that sequence dictates structure is fundamental to understanding the activity and assembly of proteins. This idea has been applied to all manner of oligomers but not to the behavior of cyclic oligomers, aka macrocycles. We do this here by providing the first proofs that sequence controls the hierarchical assembly of nonbiological macrocycles, in this case, at graphite surfaces.

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

Hierarchical assembly provides a route to complex architectures when using building blocks with strong and structurally well-defined recognition elements. These rules are traditionally expressed using cationic templates with reliable metal-ligand bonding but use of anions is rare on account of weak anion-host contacts. We investigate an approach that relies on host-host interactions to fortify assemblies formed between bisulfate anion dimers, [HSO4⋅⋅⋅HSO4] , and shape-persistent macrocycles called tricarbazole triazolophanes.