Theoretical Chemistry Ultraviolet and Visible Spectra

Physical Properties and Theoretical Chemistry 1. Theoretical Chemistry, Ultraviolet and Visible Spectra 

Since the last review5 a few calculations have been reported on quino-lizinium salts. Flurry90 used the Pariser-Parr Pople SCMO method to calculate ionization potential and transitions. Galasso91 used the 

Their calculated value for the 7r-ionization potential was 14.111 eV no experimental value is available. Galasso94 has also used Pariser-Parr Pople calculations on the three benzoquinolizinium ions to produce charge densities and transition energies. Molecular orbital calculations of LUMO and HOMO levels in the benzo[/ ]quinolizinium ion have been used in a discussion of the mechanism of cationic polar cycloaddition (Section IV,E).95 The binding energy of the positive nitrogen in the benzoquinolizinium salts has been measured relative to that of nitrate, and has been found to be 7.8-8.1 eV.96 

The pKa values have been determined spectroscopically for the 2-hydroxy-quinolizinium ion106 and all four hydroxyquinolizinium species.107 In the detailed study107 which included related aromatic systems some attempts were made at a correlation of p/Ca and effective -electron density. The pKa 

Pavelka and J. Kovar, Collect. Czech. Chem. Commun. 41, 3654 (1976). 

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