Difluorenyl carbo-Benzenes: Synthesis, Electronic Structure, and Two-Photon Absorption Properties of Hydrocarbon Quadrupolar Chromophores.
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 (C-C bonds for 3 a, C-C=C-C expanders for 3 b), exhibit quasi-superimposable one-photon absorption (1PA) spectra but different two-photon absorption (2PA) cross-sections σ2PA. Z-scan measurements (under NIR femtosecond excitation) indeed showed that the C≡C expansion results in an approximately twofold increase in the σ2PA 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 Au and Ag symmetry accounting for 1PA and 2PA, respectively, were calculated at the TDDFT level of theory and used for sum-over-state estimations of σ2PA(λi), in which λi = 2 hc/Ei, h is Planck's constant, c is the speed of light, and Ei is the energy of the 2PA-allowed transition. The calculated σ2PA 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.
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse CEDEX 4 (France).|Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France).|Kiev National Taras Shevchenko University, 60 Volodymyrska Str., 01033 Kiev (Ukraine).
Iaroslav
I
Baglai
Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto. (México), Fax: (+33) 5-61-55-30-03.
Manuel
M
de Anda-Villa
Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto. (México), Fax: (+33) 5-61-55-30-03.
Rodrigo M
RM
Barba-Barba
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse CEDEX 4 (France).|Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France).
Corentin
C
Poidevin
Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto. (México), Fax: (+33) 5-61-55-30-03. garamoso@cio.mx.
Gabriel
G
Ramos-Ortíz
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse CEDEX 4 (France). chauvin@lcc-toulouse.fr.|Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France). chauvin@lcc-toulouse.fr.
Valérie
V
Maraval
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse CEDEX 4 (France).|Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France).
Christine
C
Lepetit
Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France).
Nathalie
N
Saffon-Merceron
Centro de Investigaciones en Óptica A.P. 1-948, 37000 León, Gto. (México), Fax: (+33) 5-61-55-30-03.
José-Luis
JL
Maldonado
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099, 31077 Toulouse CEDEX 4 (France). valerie.maraval@lcc-toulouse.fr.|Université de Toulouse, UPS, ICT-FR 2599, 31062 Toulouse CEDEX 9 (France). valerie.maraval@lcc-toulouse.fr.
Remi
R
Chauvin
carbo-mers; charge transfer; chromophores; density functional calculations; nonlinear optics