title: Structural Control of Bisurea-Based Supramolecular Polymers: Influence of an Ester Moiety.
abstract: A few examples of monomers are known that self-assemble into various high molar mass structures in solution. Controlling the morphology of the resulting supramolecular polymers is a highly desirable goal for many applications. Herein, we compare the self-assembling properties of newly prepared ester bisurea monomers with those of previously investigated alkyl bisurea monomers. The ester functionality decreases the hydrogen bonding strength of the bisurea monomers but does not prevent the formation of long assemblies in nonpolar solvents: gels are formed at millimolar concentration. Surprisingly, ester bisureas self-assemble at room temperature into rod-like urea-bonded supramolecular polymers that are different from the ones formed by alkyl bisureas. The rods formed by ester bisurea supramolecular polymers are compact (instead of tubular in the case of alkyl bisureas) and display two monomers in the cross-section (instead of three in the case of alkyl bisureas). The stability of the structures formed by ester bisureas can be easily tuned by changing the nature of the substituent in the α-position of the urea functions and/or the nature of the alkyl side chains.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Dirany
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Virgile
authors.initials: V
authors.lastname: Ayzac
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Isare
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Raynal
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bouteiller