title: Design of organic molecules with large two-photon absorption cross sections.
abstract: A strategy for the design of molecules with large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectively.
authors.affiliation: School of Applied Physics and Engineering, and Developmental Resource for Biophysical Imaging Opto-Electronics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: M
authors.initials: M
authors.lastname: Albota
authors.forename: D
authors.initials: D
authors.lastname: Beljonne
authors.forename: J L
authors.initials: JL
authors.lastname: Brédas
authors.forename: J E
authors.initials: JE
authors.lastname: Ehrlich
authors.forename: J Y
authors.initials: JY
authors.lastname: Fu
authors.forename: A A
authors.initials: AA
authors.lastname: Heikal
authors.forename: S E
authors.initials: SE
authors.lastname: Hess
authors.forename: T
authors.initials: T
authors.lastname: Kogej
authors.forename: M D
authors.initials: MD
authors.lastname: Levin
authors.forename: S R
authors.initials: SR
authors.lastname: Marder
authors.forename: D
authors.initials: D
authors.lastname: McCord-Maughon
authors.forename: J W
authors.initials: JW
authors.lastname: Perry
authors.forename: H
authors.initials: H
authors.lastname: Röckel
authors.forename: M
authors.initials: M
authors.lastname: Rumi
authors.forename: G
authors.initials: G
authors.lastname: Subramaniam
authors.forename: W W
authors.initials: WW
authors.lastname: Webb
authors.forename: X L
authors.initials: XL
authors.lastname: Wu
authors.forename: C
authors.initials: C
authors.lastname: Xu
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005453:Fluorescence; D010777:Photochemistry; D017785:Photons; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: C114558:4,4'-bis(di-n-butylamino)stilbene; D000814:Aniline Compounds; D013267:Stilbenes