title: Photophysical and laser properties of cassettes based on a BODIPY and rhodamine pair.
abstract: This work deals with the synthesis and the photophysical and laser properties of new BODIPY-rhodamine cassettes. These dyads differ in their rigid and conjugated spacer group (phenyl or acetylenephenyl) and in their linking positions (meta or para). The photophysical properties of these cassettes are controlled by the formation/opening of the spirolactone ring, which, in turn, switches off/on an energy-transfer process between the chromophores. Herein, we thoroughly describe the influence of the attached spacer group, as well as the distance and orientation between the donor-acceptor pair, on the excitation energy transfer. The observed fast dynamics and efficiency suggest that the process mainly takes place "through-bond", although the "through-space" mechanism also contributes to the whole process. As a result, efficient laser emission from the rhodamine is achieved upon excitation of the BODIPY, in particular for the cassette that contains an acetylenephenyl spacer group in a para disposition.
authors.affiliation: Departamento de Química Física, Universidad del País Vasco (UPV-EHU), Aptdo 644, 48080, Bilbao (Spain).
authors.forename: Leire
authors.initials: L
authors.lastname: Gartzia-Rivero
authors.forename: Haibo
authors.initials: H
authors.lastname: Yu
authors.forename: Jorge
authors.initials: J
authors.lastname: Bañuelos
authors.forename: Iñigo
authors.initials: I
authors.lastname: López-Arbeloa
authors.forename: Angel
authors.initials: A
authors.lastname: Costela
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Garcia-Moreno
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
keywords: BODIPY; dyes; energy transfer; laser chemistry; rhodamine