Semiempirical ZINDO/S, AM1 and ab initio HF/STO-3G and HF/6-31G study of quaternary salts of diazaphenanthrenes with ethyl bromide and 1,3-dibromopropane

For quaternary salts of isomeric 1,5-, 1,6- and 4,6- diazaphenanthrenes 1-3 with ethyl iodide 4,5 and with 1,3-dibromopropane 6-8 the UV spectral values have been calculated by ZINDO/S CI 20 and by AM1 CI 12 and AM1 CI 20 methods. Correlations of experimental and calculated wavenumber values of 4, 5 and 6-8 have been made. For geometry optimization AM1 CI 20, as well as ab initio HF/STO-3G and HF/6-31G methods were used.