title: Chirality Transfer and Modulation in LB Films Derived From the Diacetylene/Melamine Hydrogen-Bonded Complex.
abstract: Introduction of hydrogen-bonding interaction into π-conjugated systems is a promising strategy, since the highly selective and directional hydrogen-bonding can increase the binding strength, provide enhanced stability to the assemblies, and position the π-conjugated molecules in a desired arrangement. The helical packing of the rigid melamine cores seems to play a dominating role in the subsequent formation of the peripheral helical PDA backbone. The polymerized Langmuir-Blodgett (LB) films exhibited reversible colorimetric and chiroptical changes during repeated heating-cooling cycles, which should be ascribed to the strong hydrogen-bonding interaction between the carboxylic acid and the melamine core. Further, the closely helical packing of the melamine cores could be destroyed upon exposure to HCl or NH(3) gas, whereas the peripheral helical polyaniline and polydiacetylene (PDA) backbone exhibited excellent stability. Although similar absorption changes could be observed for the films upon exposure to HCl or NH(3) gas, their distinct circular dichroism (CD) responses enabled us to distinguish the above two stimuli.
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, iChEM, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, iChEM, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, iChEM, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zou
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, iChEM, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
authors.forename: Qijin
authors.initials: Q
authors.lastname: Zhang
keywords: LB films; chirality; hydrogen-bonded complex; melamine; polydiacetylene