title: A Pronounced Halogen Effect on the Organogelation Properties of Peripherally Halogen Functionalized Poly(benzyl ether) Dendrons.
abstract: An interesting halogen-substituent effect on the organogelation properties of poly(benzyl ether) dendrons is reported. A new class of poly(benzyl ether) dendrons with halo substituents decorating their periphery was synthesized and fully characterized. A systematic study on the gelation abilities, thermotropic behaviors, aggregated microstructures, and mechanical properties of self-assembled organogels was performed to elucidate the halogen-substituent effects on their organogelation propensity. It was found that the exact halogen substitutions on the periphery of dendrons exert a profound effect on the organogelation propensity, and dendrons Gn -Cl (n=2, 3) and G2 -I proved to be highly efficient organogelators. The cooperation of multiple π-π, dispersive halogen, CH-π, and weak C-H⋅⋅⋅X hydrogen-bonding interactions were found to be the key contributor to forming the self-assembled gels. Dendritic organogels formed from Gn -Cl (n=2, 3) in 1,2-dichloroethane exhibited thixotropic-responsive properties, and such thixotropic organogels are promising materials for future research and applications.
authors.affiliation: Beijing National Laboratory for Molecular Sciences and CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P.R. China. fengyu211@iccas.ac.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Beijing National Laboratory for Molecular Sciences and CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Beijing National Laboratory for Molecular Sciences and CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P.R. China.
authors.forename: Zhi-Xiong
authors.initials: ZX
authors.lastname: Liu
authors.affiliation: Beijing National Laboratory for Molecular Sciences and CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P.R. China.
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: He
authors.affiliation: Beijing National Laboratory for Molecular Sciences and CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P.R. China.
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Fan
keywords: dendrons; halogens; substituent effects; supramolecular chemistry; thixotropy