title: Dendrimeric oligo(phenylenevinylene)-extended dithieno[3,2-b:2',3'-d]phospholes-synthesis, self-organization, and optical properties.
abstract: A boost from the branches: Incorporation of the dithieno[3,2-b:2',3'-d]phosphole system as a core in oligo(phenylenevinylene) dendrimers (an example is shown here) provides materials that exhibit energy-transfer features relaying incoming photons from the dendrons towards the core, which in turn shows enhanced emission intensity. The optical properties and self-assembly features of the dendrimers can be impacted by the terminal groups (-H, -CF(3), or -NPh(2)) employed.To establish this system as a fluorescent core in pi-conjugated dendrimers, a series of oligo(phenylenevinylene) (OPV)-extended dithieno[3,2-b:2',3'-d]phospholes has been prepared by means of a Wittig-Horner protocol with a dithienophosphole dialdehyde and appropriately functionalized phosphonates. The "zero-generation" model compounds have provided the general accessibility of OPV-functionalized dithienophospholes, and show varying emission colors covering the optical spectrum from green to red. Expansion of the synthetic strategy towards the corresponding first-generation dendrimers has provided materials that show intriguing self-organization features in case of the phenyl-terminated dendrimer, forming large one-dimensional microfibres, as well as desirable energy-transfer processes from the dendrons to the dithienophoshole core resulting in an enhanced emission intensity for the latter. The present study has revealed that the terminal end-groups of the OPV branches have significant impact on the optical features of the OPV dendrimers as a whole.
authors.affiliation: Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Canada.
authors.forename: Carlos
authors.initials: C
authors.lastname: Romero-Nieto
authors.forename: Sonia
authors.initials: S
authors.lastname: Merino
authors.forename: Julián
authors.initials: J
authors.lastname: Rodríguez-López
authors.forename: Thomas
authors.initials: T
authors.lastname: Baumgartner