Photoionization of propylene, cyclopropane, and ethylene. The effect of internal energy on the bimolecular reactions of C2H+4 and C3H+6

Th e ionmo lec u le c he mi s t ry occ urrin g in photo ion ized eth yle ne . prop yle ne a nd cyc lop rop an e ha s bee n in ves tiga ted in th e N BS hi g h press ure ma ss s pect rome te r. Empha s is has bee n pl ace d on d ete rmin ing th e ove ra ll e ffe c t of int e rn a l e xc it ati o n o n th e abso lut e ra te c oe ffi c ie nt s for th e va ri o us re ac ti o ns. T hi s was acco mpli s he d by c o mpari ng th e be h av ior fo und wh e n ioni za ti on was in du ced by photon abso rpti o n at th e ion iza ti o n thres hold with th a t fo un d at hi ghe r photo n e ne rgies. T he va lu es fo r th e a bso lute rat e coe ffic ie nt s fo r th e formation of e xc it ed co mpo und io ns at variou s photo n e ne rgies we re a s foll o ws (unit s of 10-'0 c m"/ mol ec ul e ' s); C, H.i . 9.6 (10.6 e V phot o ns) ; 8.5 (l 1. 7 eV phot o ns); G, H, ; . 8.4 (10. 0 e V photo ns); 6.8 (11.7 e V photon s); G,D,! . 7.8 (10.0 e V p ho ton s). 6.1 (1 1. 7 e V pho ton s) ; c-C Hi, a nd c-G. D, ; . 2.2 (10.0 e V photon s); 2.2 (1 1. 7 e V photo ns). Th e di s trib ut io ns of prod uc t io ns o btain