Ionisation of cyano derivatives: a Penning ionisation electron spectroscopy and theoretical self-consistent field/configuration interaction study

Penning ionisation electron spectroscopy (PIES) experiments are reported for acetonitrile (CH 3 CN), acrylonitrile (CH 2 CHCN) and polyacrylonitrile films. Self-consistent field/configuration interaction calculations on CH 3 CN and CH 2 CHCN using spatially selected localised orbitals show that the major feature of the PIES spectra is ionisation of the nitrogen lone pair, whose potential appears essentially constant in the series of CN-substituted molecules.