State-Resolved Reaction Dynamics
Abstract
Reactions of state-selected ammonia cation with D2, D2O, and CD4 were studied using a guided-ion beam instrument. The influence of vibrational and collision energy on these reactions was investigated by measuring cross sections for reaction of (NH3)(+) created with varying degrees of excitation in the umbrella bending- and symmetric stretching-modes. A comparison of the product cross sections from (NH3)(+) created in two states of nearly identical internal energies, but different concerted atom motions indicated that none of these reactions is mode-selective. The state-to-state ion-molecule reaction (ND3)(+) + D2O -- (ND4)(+) + OD was investigated. Rotational distributions were determined for the fine-structure states of the OD product for the reaction of vibrationally excited reactant ion. We also studied the proton transfer channel for the reaction of (HBr)(+) with HBr. We developed two approaches exploiting optical laser sources to diagnose specific chemical species present in hostile environments In particular, cavity ring-down spectroscopy and two-photon light induced fluorescence were deployed to detect potential reactants present in a hot-filament chemical vapor deposition system used to grow diamond films. Finally, we used quadrupole mass spectrometry to detect the diatomic dications (BaX)(2+) (X=F, Cl, Br, I), (SrCl)(2+), (CaBr)(2+), and (MgBr)(2+).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1998
- Accession Number
- ADA350955
Entities
People
- Richard Zare
Organizations
- Stanford University