Premium
A Competing Hydrogen Bonding Pattern to Yield a Thermo‐Thickening Supramolecular Polymer
Author(s) -
Ayzac Virgile,
Sallembien Quentin,
Raynal Matthieu,
Isare Benjamin,
Jestin Jacques,
Bouteiller Laurent
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201908954
Subject(s) - hydrogen bond , supramolecular chemistry , supramolecular polymers , urea , rod , polymer , yield (engineering) , viscosity , polymer chemistry , materials science , glass transition , chemical engineering , supramolecular assembly , crystallography , chemistry , molecule , organic chemistry , composite material , crystal structure , medicine , alternative medicine , pathology , engineering
of competing interactions in the design of a supramolecular polymer (SP) creates pathway complexity. Ester–bis‐ureas contain both a strong bis‐urea sticker that is responsible for the build‐up of long rod‐like objects by hydrogen bonding and ester groups that can interfere with this main pattern in a subtle way. Spectroscopic (FTIR and CD), calorimetric (DSC), and scattering (SANS) techniques show that such ester–bis‐ureas self‐assemble into three competing rod‐like SPs. The previously unreported low‐temperature SP is stabilized by hydrogen bonds between the interfering ester groups and the urea moieties. It also features a weak macroscopic alignment of the rods. The other structures form isotropic dispersions of rods stabilized by the more classical urea‐urea hydrogen bonding pattern. The transition from the low‐temperature structure to the next occurs reversibly by heating and is accompanied by an increase in viscosity, a rare feature for solutions in hydrocarbons.