TY - JOUR
T1 - Synthesis, spectroscopy, nonlinear optics, and theoretical investigations of thienylethynyl octopoles with a tunable core
AU - Oliva, María Moreno
AU - Casado, Juan
AU - Navarrete, Juan T.López
AU - Hennrich, Gunther
AU - Van Cleuvenbergen, Stijn
AU - Asselberghs, Inge
AU - Clays, Koen
AU - Delgado, M. Carmen Ruiz
AU - Brédas, Jean Luc
AU - De Melo, J. Sérgio Seixas
AU - De Cola, Luisa
PY - 2009/8/17
Y1 - 2009/8/17
N2 - We have synthesized three new molecules that have three thienylethynyl arms substituting a central benzene core and different electron donor/acceptor groups in the three remaining phenyl positions. The absorption, fluorescence, phosphorescence, and transient triplet-triplet spectra are analyzed in the light of the electronic structure of the ground and excited states obtained from quantum-chemical calculations. From the above, the relevant photophysical data (including quantum yields, lifetimes, and rate constants) could be derived. It was found that the major deactivation pathway is internal conversion, which competes with the fluorescence and intersystem crossing processes. For the three investigated compounds, we provide convincing theoretical support corroborating these findings and further conclusions based on the theoretical information obtained. These molecules are one of the very few cases in which the depolarization ratios, obtained from the NLO optical measurements, clearly reflect the octopolar configuration. Molecular hyperpolarizabilities have been measured and display a typical dependence on the donor-acceptor substitution pattern.
AB - We have synthesized three new molecules that have three thienylethynyl arms substituting a central benzene core and different electron donor/acceptor groups in the three remaining phenyl positions. The absorption, fluorescence, phosphorescence, and transient triplet-triplet spectra are analyzed in the light of the electronic structure of the ground and excited states obtained from quantum-chemical calculations. From the above, the relevant photophysical data (including quantum yields, lifetimes, and rate constants) could be derived. It was found that the major deactivation pathway is internal conversion, which competes with the fluorescence and intersystem crossing processes. For the three investigated compounds, we provide convincing theoretical support corroborating these findings and further conclusions based on the theoretical information obtained. These molecules are one of the very few cases in which the depolarization ratios, obtained from the NLO optical measurements, clearly reflect the octopolar configuration. Molecular hyperpolarizabilities have been measured and display a typical dependence on the donor-acceptor substitution pattern.
KW - Density functional calculations
KW - Donor-acceptor systems
KW - Nonlinear optics
KW - Phosphorescence
KW - Sulfur heterocycles
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U2 - 10.1002/chem.200900702
DO - 10.1002/chem.200900702
M3 - Article
AN - SCOPUS:68949144617
SN - 0947-6539
VL - 15
SP - 8223
EP - 8234
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 33
ER -