Solvatochromic Effect in a Benzimidazole-Based Betaine: Determination of the Dipole Moments and Second-Order Hyperpolarizability

• Authors: L. Ziółek , K. Palewska , J. Lipiński , J. Sworakowski , S Nes̆půrek , S. Böhm , E.C. Meister
• Languages of publication: EN

Abstracts

EN

Results of measurements of the solvent-dependent shift of the low-energy absorption band solvatochromic effect in a benzimidazole-based betaine are reported in the paper. Measurements of absorption spectra in several solvents of different polarities were performed. The solvatochromic shift of the low-lying absorption band was found to exceed 3000 cm^{-1}; the results obtained were then employed to calculate the ground- and excited-state dipole moment of the molecule. The spectroscopic measurements were supplemented by measurements of the ground-state dipole moment. A remarkable change in the charge distribution was found to occur upon the electronic excitation: both the experimental results and the calculations indicate that the ground-state dipole moment is close to 13 D, whereas in the excited state it amounts to ca. 3 D. The second-order hyperpolarizability of the molecule was calculated from the measurements; its off-resonance value amounts to ca. 20 × 10^{-40} m^{4}/V (4.8 × 10^{-30} esu), depending on the solvent used.

Keywords

EN

42.70.Jk; 33.20.-t; 42.65.An; 78.40.-q

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1995
• Volume: 88
• Issue: 2
• Pages: 283-293

Dates

published

1995-08

received

1995-03-06

(unknown)

1995-05-16

Contributors

author

L. Ziółek

• Institute of Physical and Theoretical Chemistry, Technical University of Wrocław, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland

author

K. Palewska

• Institute of Physical and Theoretical Chemistry, Technical University of Wrocław, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland

author

J. Lipiński

• Institute of Physical and Theoretical Chemistry, Technical University of Wrocław, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland

author

J. Sworakowski

• Institute of Physical and Theoretical Chemistry, Technical University of Wrocław, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland

author

S Nes̆půrek

• Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 16206 Prague, Czech Republic

author

S. Böhm

• Prague Institute of Chemical Technology, 16628 Prague 6, Czech Republic

author

E.C. Meister

• Laboratory of Physical Chemistry, Federal Technical University (ETH), 8092 Zurich, Switzerland