Flash spectroscopy with mercury resonance radiation. Part 4.—Measurement of mercury hydride yields with a nitric oxide titration

Abstract

By comparing the yields of HNO in the Hg-flash-photosensitized decomposition of H₂+ NO mixtures with those formed in H₂+ C₂H₄+ NO mixtures, k₄/(k₃+k₄) for the reactions, Hg(6³P₁)+[graphic omitted], was recorded as 0.67(± 0.04). Without added C₂H₄, both HgH and H are converted to HNO. Added C₂H₄ scavenges atomic hydrogen and the only HNO forming reaction is HgH + NO → HNO + Hg. In similar experiments with D₂ the equivalent k₄/(k₃+k₄) was recorded as 0.76(± 0.05). The HNO and DNO were monitored photoelectrically via their systems in the far ultra-violet. The absolute quantum yield for dissociation of H₂ by Hg(6³P₁) was recorded as 0.93(± 0.10) by comparing the HNO yields in H₂+ NO mixtures with those in C₃H₈+ NO mixtures. Less than 5% of the reaction of C₂H₅ with NO produces HNO at high pressure, and there is no fast removal of HNO by C₂H₄. Fragments of several new systems of HgH and HgD were detected in the far ultra-violet.