title: The synthesis and one- and two-photon optical properties of dipolar, quadrupolar and octupolar donor-acceptor molecules containing dimesitylboryl groups.
abstract: Two series of related donor-acceptor conjugated dipolar, pseudo-quadrupolar (V-shaped) and octupolar molecular systems based on the p-dimesitylborylphenylethynylaniline core, namely, 4-(4-dimesitylborylphenylethynyl)-N,N-dimethylaniline, 4-[4-(4-dimesitylborylphenylethynyl)phenylethynyl]-N,N-dimethylaniline, 3,6-bis(4-dimesitylborylphenylethynyl)-N-n-butylcarbazole and tris[4-(4-dimesitylborylphenylethynyl)phenyl]amine, and on the E-p-dimesitylborylethenylaniline motif, namely, E-4-dimesitylborylethenyl-N,N-di(4-tolyl)aniline, 3,6-bis(E-dimesitylborylethenyl)-N-n-butylcarbazole and tris(E-4-dimesitylborylethenylphenyl)amine have been synthesised by palladium-catalyzed cross-coupling and hydroboration routes, respectively. Their absorption and emission maxima, fluorescence lifetimes and quantum yields have been obtained and their two-photon absorption (TPA) spectra and TPA cross-sections have been examined. Of these systems, the octupolar compound tris(E-4-dimesitylborylethenylphenyl)amine has been shown to exhibit the largest TPA cross-section among the two series of approximately 1000 GM at 740 nm. Its TPA performance is comparable to those of other triphenylamine-based octupoles of similar size. The combination of such large TPA cross-sections and high emission quantum yields, up to 0.94, make these systems attractive for applications involving two-photon excited fluorescence (TPEF).
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Collings
authors.forename: Suk-Yue
authors.initials: SY
authors.lastname: Poon
authors.forename: Céline
authors.initials: C
authors.lastname: Le Droumaguet
authors.forename: Marina
authors.initials: M
authors.lastname: Charlot
authors.forename: Claudine
authors.initials: C
authors.lastname: Katan
authors.forename: Lars-Olof
authors.initials: LO
authors.lastname: Pålsson
authors.forename: Andrew
authors.initials: A
authors.lastname: Beeby
authors.forename: Jackie A
authors.initials: JA
authors.lastname: Mosely
authors.forename: Hanns Martin
authors.initials: HM
authors.lastname: Kaiser
authors.forename: Dieter
authors.initials: D
authors.lastname: Kaufmann
authors.forename: Wai-Yeung
authors.initials: WY
authors.lastname: Wong
authors.forename: Mireille
authors.initials: M
authors.lastname: Blanchard-Desce
authors.forename: Todd B
authors.initials: TB
authors.lastname: Marder