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Journal articles
Two-Photon Absorption and Two-Photon Circular Dichroism of a Hexahelicene Derivative with a Terminal Donor-Phenyl-Acceptor Motif
Abstract : Herein, we report on the theoretical-experimental analysis of the two photon absorption and circular dichroism spectra of 1-(2-pyridyl)-4-methoxy-carbo[6]helicene derivative (P6). The primary outcomes of our investigation on this particular helicene derivative with a donor-acceptor motif on one end led to two important conclusions (1) the lengthening of the π-electron delocalization within the helical core of P6 predominantly increases the contribution of the magnetic dipole transition moment to the two-photon circular dichroism (TPCD) signal; and (2) the electric quadrupole transition moment contribution to the TPCD signal is enhanced by the intramolecular charge transfer (ICT) produced by the donor-acceptor combination on one end of the molecule. To corroborate our results, we performed a comparative theoretical analysis of the effect of the energy gap and ICT on TPCD on a series of P6-like helicenes with different donor-acceptor combinations. Two-photon absorption and TPCD spectra were obtained using the double L-scan technique over a broad spectral range (400-900 nm) using 90 fs pulses at a low repetition rate (2-50 Hz) produced by an amplified femtosecond system. The theoretical simulations were calculated using time dependent density functional theory at the CAM-B3LYP/6-311++G(d,p) level of theory.
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01771522
Contributor : Laurent Jonchère <>
Submitted on : Friday, June 8, 2018 - 1:27:16 PM
Last modification on : Thursday, March 5, 2020 - 2:03:37 PM
Long-term archiving on: : Sunday, September 9, 2018 - 5:51:17 PM
Contributor : Laurent Jonchère <>
Submitted on : Friday, June 8, 2018 - 1:27:16 PM
Last modification on : Thursday, March 5, 2020 - 2:03:37 PM
Long-term archiving on: : Sunday, September 9, 2018 - 5:51:17 PM
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