title: Enhanced charge-transfer emission in polyimides by cyano-groups doping.
abstract: Conjugated polyimides (PI) are successfully synthesized by chemical imidization through in situ silylation of diamines by the alteration of different donor-acceptor monomers. A detailed photophysical characterization is performed in the monomers and different polymers in tetrahydrofuran solutions. The emission spectra of the related donor-acceptor polymers with electron withdrawing cyano groups showed broader and more intense fluorescence bands in comparison to the polymer without -CN groups. The new emission band results from the contribution of two different charge-transfer (CT) pathways: (i) An intramolecular CT (ICT) state in the donor monomers due to the presence of strong electron withdrawing CN groups, and (ii) a intramolecular CT complex (CTC) in the PI polymer between the donor-acceptor monomers, which is red-shifted and shows longer lifetime respect to the ICT of the diamine monomers. The very wide emission band is a very interesting feature for obtaining white light from UV light.
authors.affiliation: †Basque Center for Materials, Applications, and Nanostructures (BCMaterials), Parque Científico y Tecnológico de Bizkaia, Camino de Ibaizabal, Building 500-1st, 48160 Derio, Spain.
authors.forename: María
authors.initials: M
authors.lastname: San Sebastián
authors.forename: Virginia
authors.initials: V
authors.lastname: Martínez-Martínez
authors.forename: Alberto
authors.initials: A
authors.lastname: Maceiras
authors.affiliation: †Basque Center for Materials, Applications, and Nanostructures (BCMaterials), Parque Científico y Tecnológico de Bizkaia, Camino de Ibaizabal, Building 500-1st, 48160 Derio, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Vilas
authors.forename: Iñigo
authors.initials: I
authors.lastname: López-Arbeloa
authors.affiliation: †Basque Center for Materials, Applications, and Nanostructures (BCMaterials), Parque Científico y Tecnológico de Bizkaia, Camino de Ibaizabal, Building 500-1st, 48160 Derio, Spain.
authors.forename: Luis Manuel
authors.initials: LM
authors.lastname: León