Negative ion photoelectron spectroscopy of halocarbene anions (HCF-, HCCl-, HCBr-, and HCI-); photoelectron angular distributions and neutral triplet excitation energies

Photoelectron spectra and angular distributions are reported for the HCX( 1 A')+e - ←HCX - (X 2 A'') and HCX( 3 A'')+e - ←HCX - (X 2 A'') transitions of the halocarbenes (X=F, Cl, Br, and I). Taking photoelectron spectra at parallel and perpendicular laser polarizations with respect to the direction of the photoelectron detection allows us to distinguish the triplet transition from the overlapping singlet transition