title: The electronic, optical and magnetic consequences of delocalization in multifunctional donor-acceptor organic polymers.
abstract: Two organic polymers containing alternating electron donating triarylamine and electron accepting thiazolo[5,4-d]thiazole (TzTz) moieties have been synthesized and their redox states investigated. When donor and acceptor units are proximal (polymer )1, electron density is delocalized, leading to a small electrical and optical band gap; these are larger with the inclusion of an adjoining alkynyl-phenyl bridge (polymer 2), where electron density is more localized due to the rotation of the monomer units. As a result, 1 and 2 display different optical and fluorescence properties in their neutral states. Upon chemical and electrochemical redox reactions, radicals form in both 1 and 2, yielding magnetic materials that display temperature-independent paramagnetism, attributable to delocalization of radical spins along the polymeric backbones. The ability to convert between diamagnetic and paramagnetic states upon chemical oxidation and/or reduction allows for the materials to display switchable magnetism and fluorescence, imparting multifunctionality to these solid-state purely organic materials.
authors.affiliation: School of Chemistry, The University of Sydney, NSW 2006, Australia. deanna.dalessandro@sydney.edu.au.
authors.forename: Felix J
authors.initials: FJ
authors.lastname: Rizzuto
authors.forename: Carol
authors.initials: C
authors.lastname: Hua
authors.forename: Bun
authors.initials: B
authors.lastname: Chan
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Faust
authors.forename: Aditya
authors.initials: A
authors.lastname: Rawal
authors.forename: Chanel F
authors.initials: CF
authors.lastname: Leong
authors.forename: James M
authors.initials: JM
authors.lastname: Hook
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Kepert
authors.forename: Deanna M
authors.initials: DM
authors.lastname: D'Alessandro