Size compatibility and concentration dependent supramolecular host–guest interactions at interfaces

Abstract

The quantification of supramolecular host–guest interactions is important for finely modulating supramolecular systems. Previously, most host–guest interactions quantified using force spectroscopic techniques have been reported in force units. However, accurately evaluating the adhesion energies of host–guest pairs remains challenging. Herein, using a surface forces apparatus, we directly quantify the interaction energies between cyclodextrin (CD)-modified surfaces and ditopic adamantane (DAd) molecules in water as a function of the DAd concentration and the CD cavity size. The adhesion energy of the β-CD–DAd complex drastically increased with increasing DAd concentration and reached saturation. Moreover, the molecular adhesion energy of a single host–guest inclusion complex was evaluated to be ~9.51 kBT. This approach has potential for quantifying fundamental information toward furthering the understanding of supramolecular chemistry and its applications, such as molecular actuators, underwater adhesives, and biosensors, which require precise tuning of specific host–guest interactions.

Switchable Separation Strategy via Host–Guest Locks

“…34 Two guest molecules were chosen for study: cationic AD (G1) as a control and anionic AD (G2) as the target guest (Figure 2A). Except for the excellent size compatibility between the CD cavity and the AD skeleton, 35,36 we also introduced an auxiliary electrostatic unit (imidazolium and carboxyl) to more firmly embed the guest in the CD cavity (in the case of G2). 37 Analysis of Host−Guest Inclusions in Solution.…”

Building a Versatile Platform for the Detection of Protein–Protein Interactions Based on Organic Field-Effect Transistors

“…Based on the previous literature and material properties, we anticipate GPTMS molecules to self-assemble in a manner that positions methoxysilane groups close to the P(DPP-TVT) layer, thereby directing the epoxy terminal groups to the surface. 50,51 A noticeable change was observed in surface topography after immobilizing UbV8.2 onto the GPTMS surface, leading to globular-shaped particles with distinctly different compositions than those of the underlying layer (observed in the AFM phase image shown in Figure S5). Furthermore, we observed a moderate decrease in the surface roughness values after UbV8.2 immobilization (≈0.5 nm).…”

A novel 2,6-bis(benzoxazolyl)phenol macrocyclic chemosensor with enhanced fluorophore properties by photoinduced intramolecular proton transfer

“…The ligand was purified as a tetraperchlorate salt (L•4HClO 4 ) by re-crystallization from a hot ethanol/70% aqueous perchloric acid mixture. The key intermediate 6 was synthesized by radical bromination with NBS of the dimethyl-analogue 2,6-bis(4-methylbenzoxazol-2-yl) anisole (5), which was obtained in turn by condensation of 2-methoxyisophthalic acid (2) with two equivalents of 2-amino-3-methylphenol (3) in polyphosphoric acid (PPA) at 160 °C. This reaction led to the de-methylation of the phenol group (4); thus, a further methylation step was necessary to obtain the protected fluorophore (5).…”