74 



CHEMICAL REACTIONS IN THE GAS PHASE 



of this excess as translational energy. The efficiency of collection of 

 such ions will be very low in most mass spectrometers (2), and those 

 that appear will come at an accelerating potential or magnetic field 



Fig. 1. Potential energy functions for a few possible states of a diatomic molecule, 

 indicating some of the dissociation processes and products which can result from a 



single electron impact. 



corresponding to a mass slightly greater than the true value. Transi- 

 tions to state V, if the Franck-Condon rule is strictly applicable, can 

 yield directly only molecular ions, but as this state is above the asymp- 

 tote for formation of A"*" + B, secondary reactions can occur: (a) there 



i 



