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Electronic Structure and Photophysical Properties of Isoindole and its Benzo[ f ]‐ and Dibenzo[ e,g ]‐Derivatives
Author(s) -
Rettig Wolfgang,
Wirz Jakob
Publication year - 1976
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19760590411
Subject(s) - isoindole , chemistry , phosphorescence , absorption spectroscopy , spectroscopy , fluorescence , crystallography , photochemistry , spectral line , fluorescence spectroscopy , stereochemistry , physics , quantum mechanics , astronomy
The synthesis of N‐methyl‐benz[f]isoindole ( 2 ) and N‐methyl‐dibenz[e,g]isoindole ( 3 ) is reported. The NMR. spectra of N‐methyl‐isoindole ( 1 ) and of 2 have been analysed and the implications concerning the alternation of bond lengths are discussed. The photophysical properties of 1 to 3 have been investigated by the following methods: HeI photoelectron (PE.) spectroscopy, UV./VIS. absorption (polarization measurements by the stretched‐foil technique) and emission spectroscopy (fluorescence spectra, lifetimes and quantum yields, phosphorescence spectra), and flash spectroscopy (triplet‐triplet absorption spectra). The discussion of the results is based on HMO. and PPP SCF CI. calculations and points to the relationship between the heterocycles 1 to 3 and the corresponding benzenoid hydrocarbons obtained by replacement of the NMesubunit by CHCH. Some comments concerning the ground state properties of isoindole and related compounds are derived from the analysis of their electronic structure.