Blue two-photon excited fluorescence of several D-π-D, A-π-A, and D-π-A compounds featuring dimesitylboryl acceptor

Several donor-pi-donor (D-pi-D), acceptor-pi-acceptor (A-pi-A), and donor-pi-acceptor (D-pi-A) types of organic compounds with fluorene as pi bridge and dimesitylboryl group as electron acceptor, which show strong two-photon excited blue fluorescence, have been synthesized and structurally investigated. The symmetric A-pi-A type of compound exhibits the shortest wavelength of two-photon excited fluorescence (TPEF) at lambda(em) = 405 nm under the excitation of lambda(ex) = 730 nm; the unsymmetric D-pi-A type of compound with diphenylamino as donor exhibits the most intense TPEF at blue region (lambda(em) = 484 nm) with a two-photon absorption cross-section of 425 GM under lambda(ex) = 800 nm. (C) 2004 Elsevier B.V. All rights reserved.