Entropy driven chain effects on ligation chemistry

Abstract

Entropic chain effects on dynamic bonding reactions are shown to enable the tuning of reaction equilibria not only by changing the mass of the reactants, but also by merely altering the building block side chain structure and thus the intrinsic stiffness. The findings enable a step change for the design of on-demand bonding systems and reversible ligation chemistry in general.

An in-depth analysis approach enabling precision single chain nanoparticle design

“…4.6 nm found for poly( t Bu acrylate). 83 The shortest lK, thus, the most flexible chain, is found for the precursor 20C, whereas sample 50C shows the longest lK -although both precursors exhibit a comparable backbone composition. Generally, the A-samples show better flexibility, thus, the low crosslinking turnover of the low functionalized precursor is not caused by steric hindrance of potentially stiff backbone features, but is solely caused by statistically reduced intramolecular ligation events.…”

Thermal Field‐Flow Fractionation for the Investigation of the Thermoresponsive Nature of Star and Linear Polystyrene

“…Temperature‐responsive (or thermoresponsive) polymers are polymers that exhibit discontinuous changes of their physical properties, for example, solubility or hydrodynamic size in a given solvent, with temperature . Promising areas of application of thermoresponsive polymers are tissue engineering, liquid chromatography, self‐healing materials, drug delivery, and bioseparation . Typically, the solution properties of thermoresponsive polymers (such as the phase transition temperature) are influenced by a number of molecular parameters such as molar mass and molecular topology .…”

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2s + 4s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans

“…For example, the highly electron-deficient dithioesters that are present as end-groups of polymers obtained via the reversible addition-fragmentation chain transfer polymerization using specially designed chain transfer agents have been utilized for HDA reactions by Barner-Kowollik and coworkers. [8][9][10][11][12][13][14][15][16][17][18] Networks based on tetrafunctional dithioesters and bifunctional cyclopentadiene showed self-healing behavior. [19] Moreover, Lehn and coworkers investigated highly reversible and dynamic DA systems.…”