80581-50-6Relevant academic research and scientific papers
Chiroptical Properties of 10,11-Dihydro-5,10-methano-5H-dibenzocycloheptene Derivatives
Hagishita, Sanji,Kuriyama, Kaoru
, p. 2790 - 2801 (1981)
The title compounds have been prepared from (+)-(9R,10R)-dimethyl 11-oxo-9,10-dihydro-9,10-ethanoanthracene-1,5-dicarboxylate.Their absolute configurations were determined by chemical reaction, and by IR and CD spectra.Although the CD spectra of 2 and 3 (R=NH2) were expected to show an antipodal pattern from analysis of the simple coupling mechanism, they showed approximately the same magnitude of the positive Cotton effect in both regions of the 1Lb and 1La benzenoid transitions.Their CD spectra were calculated by the point-dipole exciton treatment and by the ?-SCF approximation using the dipole velocity procedure with and without the charge transfer transition between the aromatic chromophores.Thus, the electric transition dipole moment should not be treated as a point dipole at any place and the rotational strength should be calculated by the dipole velocity procedure since a local magnetic transition dipole moment was produced perpendicular to the benzene ring in the region of the 1Lb transition.The charge transfer transition can not be neglected in the calculation of the MO, though it does not cause the alteration of the sequence of the coupling mode.
