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Excited‐State Dipole Moments and Transition Dipole Orientations of Rotamers of 1,2‐, 1,3‐, and 1,4‐Dimethoxybenzene
Author(s) -
Schneider Michael,
Wilke Martin,
Hebestreit MarieLuise,
Henrichs Christian,
Meerts W. Leo,
Schmitt Michael
Publication year - 2018
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.201701095
Subject(s) - conformational isomerism , dipole , excited state , transition dipole moment , bond dipole moment , chemistry , moment (physics) , electric dipole transition , ab initio quantum chemistry methods , ab initio , atomic physics , molecular electronic transition , ground state , singlet state , molecular physics , physics , magnetic dipole , quantum mechanics , molecule , organic chemistry
Rotationally resolved electronic Stark spectra of rotamers of 1,2‐, 1,3‐, and 1,4‐dimethoxybenzene have been recorded and analyzed using evolutionary strategies. The experimentally determined dipole moments as well as the transition dipole moments are compared to the results of ab initio calculations. For the electronic ground states of the experimentally observed dimethoxybenzenes, the permanent dipole moments can be obtained from vectorial addition of the monomethoxybenzene dipole moment. However, this is not the case for the electronically excited states. This behavior can be traced back to a state mixing of the lowest electronically excited singlet states for the asymmetric rotamers. For the symmetric rotamers however, this is not valid. We discuss several possible reasons for the non‐additivity of the dipole moments in the excited states of the symmetric rotamers.