Symmetry effects in site-specific fragmentation of carbon dioxide

Results are presented for the dissociation dynamics of carbon dioxide following the removal of a 1s electron from the C and O cores. A state-selected triple coincidence technique is used in combination with a monochromatic soft x-ray source and the apparatus aligned both parallel and perpendicular to the radiation polarisation vector. The data show, for the CO+ + O+ channel, dissociation preferentially perpendicular to the polarisation vector for excitation at the C 1s edge, but parallel at the O 1s edge. The same behaviour is seen for the O+ + C+ + O+ channel, although this channel is weak following O 1s excitation.