Access Type

Open Access Dissertation

Date of Award

January 2011

Degree Type


Degree Name




First Advisor

Arthur G. Suits


This work presents results of primary fundamental photodissociation and state-specific ion-molecule dynamical studies that are relevant to understanding the formation and growth mechanisms of unsaturated hydrocarbon molecules, haze layers and aerosols in Titan's upper atmosphere. In the diacetylene dimer, it is shown, via laboratory studies combined with electronic structure calculations that the photodissociation of the dimer readily initiates atomic hydrogen (H) loss and atomic H transfer reactions forming two prototypes of resonantly stabilized free radicals, C8H3 and C4H3, respectively. In ethylamine cation, high-level ab initio calculations identify the complex dissociation pathways for the ground state CH3CH2NH2+ radical cation at 233.3 nm using Direct current (DC) slice imaging technique, revealing important features of the potential surface that are important in Titan's ion-molecule reactions. Finally, a new technique is implemented to measure the branching ratios for the reactions of state-prepared N2+ ions with methane (CH4), acetylene (C2H2) ethylene (C2H4), Hydrogen (H2) and acetonitrile (CH3CN) under a rotational temperature ~40 ± 5K.