Through-bond effects in pyrazino[2,3-b]pyrazine. Photoelectron spectroscopy and model calculations
Abstract
The Helα photoelectron spectra of the title compound and four methyl derivatives are measured and analysed in terms of simple Hückel-type arguments and the results of semiempirical EWMO and HAM/3 calculations. The presence of strong through-bond interaction leading to a highly destabilized totally symmetric nitrogen ‘non-bonding’ orbital is confirmed.