Electronically Excited Alkaline Earth Oxides: Chemical Production and Collisional Energy Transfer Processes.
Abstract
A collaborative experimental and theoretical study both of the reactions of electronically excited alkaline earth atoms with molecular oxidants and of inelastic and reactive processes involving open-shell atoms and molecules has been carried out. The branching ratios for formation of ground and excited state products from the reactions of both ground state (1S) and metastable electronically excited (3Po, 1D, or 3D) Mg, Ca, Sr, and Ba were determined by chemiluminescence and laser fluorescence measurements. These results were compared wtih adiabatic correlation predictions. It was also possible to set bounds on the CaO and MgO dissociation energies. A semi-empirical representation was developed for the description of the ion-pair (M(+)O2(-)) potential energy surfaces for both alkali and alkaline earth atoms. A semi classical dipolar model was developed for the calculation of collisional interelectronic energy transfer rates between the low-lying X1sigma(+), a 3Pi, and A 1Pi states of CaO and used to interpret the observed pressure dependence of the Ca (3Po) + N2O chemiluminescence spectrum. This model was also extended to energy transfer in MgO. Originator supplied keywords include: Gas-phase collision processes; chemiluminescence; laser fluorescence; alkaline earth atoms; oxidation reactions; dissociation energies; molecular energy transfer; spin-orbit states; open-shell molecules; semi-empirical potential energy surfaces.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 22, 1985
- Accession Number
- ADA153172
Entities
People
- M. H. Alexander
- P. J. Dagdigian
Organizations
- Johns Hopkins University