The Attachment of Low-Energy Electrons to Dicyanogen in the Gas Phase

The negative ions C-, CN- and C2N- formed by the dissociative resonance attachment of low-energy electrons to dicyanogen in the gas phase have been studied over the electron impact energy range from 0 to 15 eV. The formation of the CN- ion was studied by using a 'monochromatic' electron gun and the translational energy of the ion measured as a function of the electron energy across the dissociative resonance capture curve. An energy balance analysis for CN- ion formation has been used to propose the electron capture processes and to construct a potential energy diagram (for C-C internuclear separation) for CN- ion formation. The molecular ion, C2N2-, has been shown to result from the associative resonance attachment of thermalized electrons scattered from the collision chamber surfaces and to exhibit an autodetachment lifetime in the microsecond timerange.