ELECTRONIC BRANCHING RATIOS IN THE CHEMILUMINESCENT REACTIONS OF CA(S-1) AND CA-ASTERISK(P-3) WITH ICL AND IBR

Chemiluminescence of calcium monohalides formed in the reactions of gr ound state Ca(S-1) and metastable Ca(P-3) atoms with ICl or IBr was s tudied in a beam-gas arrangement. Total collision and chemiluminescenc e cross sections were measured to estimate photon yields of electronic states of the products. For the (A(2) Pi + B-2 Sigma(+)) states, aggr egate yields appear to be arithmetic averages of the values for proper homonuclear halogen targets and branching ratios are in agreement wit h prior expectations. The experiment gives lower limits of the dissoci ation energies: D-0(CaBr) greater than or equal to 353 kJ/mol and D-0( CaI) greater than or equal to 293 kJ/mol.