Photoelectron spectroscopy of quinoline derivatives. Correlation of experimental ionization potentials with calculated molecular energies

Experimental ionization potentials of quinoline 1 and substituted quinolines: 6-methylquinoline 2, 2,6-dimethylquinoline 3, 6-methoxyquinoline it, 3-bromoquinoline 5, 2-chloro-4-methylquinoline 6, 4-hydroxyquinoline 7, 4-hydroxy-2-methylquinoline 8, 2-hydroxy-4-methylquinoline 9, 4-methoxyquinoline 10, 4- methoxy-2-methylquinoline 11, 2-methoxy-4-methylquinoline 12, were measured by photoelectron spectroscopy. Molecular orbital energies of the same derivatives were calculated by the Austin Method 1. The assignments of the bands of the photoelectron spectra were done with the aid of the theoretical calculations and on the basis of the substituent effects. For quinolines 1-6 a good agreement was found between the experimental ionization potentials and the calculated orbital energies. (C) 1997 Elsevier Science B.V.