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Two‐Photon Solvatochromism II: Experimental and Theoretical Study of Solvent Effects on the Two‐Photon Absorption Spectrum of Reichardt’s Dye
Author(s) -
Wielgus Małgorzata,
Zaleśny Robert,
Murugan N. Arul,
Kongsted Jacob,
Ågren Hans,
Samoc Marek,
Bartkowiak Wojciech
Publication year - 2013
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201300695
Subject(s) - solvatochromism , chemistry , solvent , solvent effects , intramolecular force , two photon absorption , absorption spectroscopy , formamide , solvation , dimethyl sulfoxide , photochemistry , polarization (electrochemistry) , chloroform , absorption (acoustics) , polarity (international relations) , optics , organic chemistry , physics , laser , biochemistry , cell
In this study, we report on the influence of solvent on the two‐photon absorption (2PA) spectra of Reichardt’s dye (RD). The measurement of 2PA cross‐sections is performed for three solvents (chloroform, dimethyl formamide, and dimethyl sulfoxide) using the Z ‐scan technique. The key finding of this study is the observation that the cross‐section, corresponding to the 2PA of the intramolecular charge‐transfer state, diminishes substantially upon increasing the solvent polarity. To unravel the solvent dependence of the 2PA cross‐section, the electronic structure of RD is determined using a hybrid quantum mechanics/molecular mechanics (QM/MM) approach, in which polarization between the solute and solvent is taken into account by using a self‐consistent scheme in the solvent polarization. The two‐state approximation proves to be adequate for the studied system, and allowed the observed solvent‐polarity‐induced decrease of the 2PA cross‐section to be related to the decrease of the transition moment and the increase in the excitation energy.