Laser - ion Beam Photodissociation Studies of C 4 H 4 Radical Cations

The laser-ion beam photodissociation for [C4H4]+' ions produced from a variety of precursors has been studied. Based on the data it is apparent that two structurally distinct forms of the [C4H4]+* ion are produced by fragmentation of larger systems. The relative population of the various structural forms is very dependent on the internal energy of the fragmenting ion, with 1-buten-3-yne [C4€L,]+' ions being favored at low internal energies. As the internal energy of the reactant ion is increased, the relative population of butatriene [C,H4]+' ions increases. The laser-ion beam photodissociation technique is able to selectively sample these two structural forms.