Spectroscopic studies of nitrogen dioxide and water via resonance enhanced multiphoton ionization and photo-electron spectroscopy, and dynamical studies with vibrationally state selected nitrogen dioxide cations

Photoelectron spectroscopy (PES) and Resonance-enhanced multiphoton ionization (REMPI) spectroscopy studies were conducted on a photoion/photoelectron time-of-flight mass spectrometer. REMPI pumping schemes for NO2, H2O, HDO and D2O are presented for the production of vibrationally state-selected ions. REMPI studies are used to search out resonant schemes and their respective intensities coupled with PES to monitor state selection and state purity. Studies of NO2 produced ions in the ground state (gs), the symmetric stretch (100), the asymmetric stretch (001), one quanta of the bend (010), and two quanta of the bend in both the Sigma (0200) and Delta (0220) symmetry. Similarly, pure state selection was achieved for the ground state (000), bend mode (010) and symmetric stretch C(100) of D2O+. For the ground state (000) and symmetric stretch (100) of H2O, the O-D, O-H stretch and ground state of HDO+, pure state selection(>90%) was achieved. The bend modes(010) of HDO and H2O are both reported to be partially mixed (50:50) with the origin. In summation, sufficient state selection and ion intensities are produced via REMPI to perform mode-specific ion-neutral dynamical studies. Two such dynamical studies are presented in this thesis.; A mode-specific dynamical study on the exothermic charge transfer of NO2+ with NO is presented. The effects of NO 2+ vibrational excitation on charge transfer (CT) with NO have been studied over the center-of-mass collision energy (Ecol) range from 0.07 to 2.15 eV. Vibrational effects are observed for both the integral and differential cross sections. At low collision energies (< 0.25 eV), charge transfer is measured to be fairly inefficient (< 20%). As collision energy increases and the collision cross section decreases, CT efficiency increases. It is found that both the bend modes and the symmetric stretch enhance CT. While the asymmetric stretch is the most energetic, it was found to have an insignificant effect on CT.; Mode specific dynamical studies are reported in collision induced dissociation (CID) reactions of NO2+ with Xe, Kr, Ar and Ne (NO2+ + Rg ⇒ NO+ + O + Rg). For CID with Xe, threshold energetics show dissociation was consistent with the production of oxygen in the spin forbidden ground triplet state dissociation channel. Collisions with the other three rare gases were found to be similar in that only dissociation to the excited singlet oxygen channel was observed. All four rare gases exhibit strong effects from NO2+ vibrational excitation that extended over the entire collision energy range.