Photoionization of C4H+8 isomers. Unimolecular and biomolecular reactions of C4H+8 ions

lBut e ne, cis2butene, iso bute ne a nd me lh ylcyclop ropa ne have bee n ph Oloioni ze d with th e reso nan ce lin es of krypton (10.0-10.6 eV) a nd argo n (11.6-11 .8 eV). We have de te rmin ed th a t th e intern aliy exc ite d ].C" H'; ion a nd , to a mu c h lesse r ex te nl , th e i,C4 l:-~+ ion iso me ri zes to th e 2 , C4 H ~ stru c ture. In both cases th e ex te nt of iso me ri za ti on in c reases , approx imatel y by a fa c tor of len whe n th e photon e ne rgy is in creased from 10 to 11.7 e V. An in e rt gas, neo n, qu enc hes the iso me ri zati on of th e i-c', Hit ion and , 10 a mu c h lesse r rex te nt , Ih a t of th e l C H; ion .