The metastable triplet state of mercury, Hg 6(3 P 0): a study of its reactions by kinetic spectroscopy

By pressure broadening of the mercury resonance line at 2537 Å (6(3P1)-6(1S0)) with a high pressure of N2, a sufficiently high concentration of Hg9(3P0) was produced by flashing mercury vapour to make possible its detection by absorption spectroscopy. Metastable atoms were also detected in flashed mixtures of H2O with argon and CO with argon. The rates of decay of the metastable atoms were measured by kinetic spectroscopy. Metastable atoms were not produced by flashing mixtures of mercury vapour in the presence of any one of the gases, H2, CO2, O2, C2H6, C2H4, NO, N2O. By adding these substances at low partial pressures to nitrogen+mercury vapour mixtures, some approximate values for their rates of reaction with Hg 6(3P0) were determined. The order of reactivity for equal pressures is N2O > C2H4 > NO > H2 > O2 > C2H6 > H2O > CO2 > N2. Metastable atoms are less reactive than Hg6 (3P1) atoms, there being a particularly large disparity for the CO2 molecule.