title: Push-pull flexibly-bridged bis(haloBODIPYs): solvent and spacer switchable red emission.
abstract: A series of uncommon bis(BODIPYs), involving a flexible bridge linking the BODIPY α-positions and key functionalities to efficiently give an electronic push-pull effect, has been synthesized, as well as photophysically and structurally studied. It is demonstrated that the designed push-pull effect efficiently enables intramolecular charge transfer (ICT) processes upon photoexcitation, with the generated low-lying ICT state being the main deactivation channel from the locally excited state and, hence, ruling the fluorescence response. Noticeably, this response is modulated by the solvent polarity, and also by the bridge structure. Regarding this, BINOL- and BINAM-based bridges are found to promote an interesting unprecedented solvent-switchable dual emission from the ICT state with high Stokes shifts, triggering a significant bright red emission in less polar media.
authors.affiliation: Departamento de Química Orgánica I, Facultad de CC. Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain. santmoya@ucm.es.
authors.forename: César
authors.initials: C
authors.lastname: Ray
authors.forename: Jorge
authors.initials: J
authors.lastname: Bañuelos
authors.forename: Teresa
authors.initials: T
authors.lastname: Arbeloa
authors.forename: Beatriz L
authors.initials: BL
authors.lastname: Maroto
authors.forename: Florencio
authors.initials: F
authors.lastname: Moreno
authors.forename: Antonia R
authors.initials: AR
authors.lastname: Agarrabeitia
authors.forename: María J
authors.initials: MJ
authors.lastname: Ortiz
authors.forename: Iñigo
authors.initials: I
authors.lastname: López-Arbeloa
authors.forename: Santiago
authors.initials: S
authors.lastname: de la Moya