Quenching of NH(a 1Δ)

The rate coefficients for quenching of metastable NH(a 1Δ) by N2, H2, HF, F2, HNCO, NH3, N2H4, and He were measured. The 193 nm ArF pulsed laser photolysis of HNCO, NH3, and N2H4 produced NH(a 1Δ). Its lifetime was measured as a function of quenching species concentration by an LIF technique which made use of the a 1Δ→c 1π transition near 325 nm.