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Difluorenyl carbo ‐Benzenes: Synthesis, Electronic Structure, and Two‐Photon Absorption Properties of Hydrocarbon Quadrupolar Chromophores
Author(s) -
Baglai Iaroslav,
de AndaVilla Manuel,
BarbaBarba Rodrigo M.,
Poidevin Corentin,
RamosOrtíz Gabriel,
Maraval Valérie,
Lepetit Christine,
SaffonMerceron Nathalie,
Maldonado JoséLuis,
Chauvin Remi
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201500482
Subject(s) - two photon absorption , chromophore , absorption (acoustics) , chemistry , excited state , femtosecond , time dependent density functional theory , molecule , absorption spectroscopy , benzene , photochemistry , crystallography , analytical chemistry (journal) , materials science , atomic physics , physics , organic chemistry , optics , laser , composite material
Abstract The synthesis, crystal and electronic structures, and one‐ and two‐photon absorption properties of two quadrupolar fluorenyl‐substituted tetraphenyl carbo ‐benzenes are described. These all‐hydrocarbon chromophores, differing in the nature of the linkers between the fluorenyl substituents and the carbo ‐benzene core (CC bonds for 3 a , CCCC expanders for 3 b ), exhibit quasi–superimposable one‐photon absorption (1PA) spectra but different two‐photon absorption (2PA) cross‐sections σ 2PA . Z ‐scan measurements (under NIR femtosecond excitation) indeed showed that the CC expansion results in an approximately twofold increase in the σ 2PA value, from 336 to 656 GM (1 GM=10 −50 cm 4 s molecule −1 photon −1 ) at λ =800 nm. The first excited states of A u and A g symmetry accounting for 1PA and 2PA, respectively, were calculated at the TDDFT level of theory and used for sum‐over‐state estimations of σ 2PA ( λ i ), in which λ i =2 hc / E i , h is Planck’s constant, c is the speed of light, and E i is the energy of the 2PA‐allowed transition. The calculated σ 2PA values of 227 GM at 687 nm for 3 a and 349 GM at 708 nm for 3 b are in agreement with the Z ‐scan results.