Decay kinetics of XeCl(B,C) in Xe and in mixtures of Xe with Kr, Ar, Ne, and He

Abstract

The two-photon, laser-assisted reaction between Xe and Cl 2 has been used to prepare XeCI (B,C) molecules in Xe and in Xe mixtures with lighter rare gases for kinetic studies of the coupled XeCI (B,C) states. The XeCI (B-X) spectra were used to assign the conditions for which the vibrational temperature was nearly 300 K. Relative intensity and coupled radiative lifetime measurements provide independent data which support an energy separation between the XeCI(B) and XeCl( C) states of -100 cm -I . The two-body quenching rate constant in Xe for XeCl (B,C) was measured as 5 ~ ~ X 10 -12 cm 3 s -I , and a three-body quenching rate constant of 13 ± 4x 10-31 cm 6 s -I is indicated. Experiments also were done with added Kr, Ar, Ne, and He to establish two-body and mixed (e.g., Xe + Ar) three-body quenching rate constants. The three-body quenching rate constants are nearly equal to the Xe 2 CI· formation rate constants and three-body dark quenching of XeCl(B,C) is negligible.

Absolute Fluorescence Yields from Electron-Irradiated Gases. 3. XeCl* and XeI*

“…25 ns 30 (corresponding to a rate constant of k 18 = 4.0 × 10 7 s -1 ). The two- and three-body rate constants for xenon quenching of XeCl* (B,C) have been directly measured as (3.0 ± 1.2) × 10 9 dm 3 mol -1 s -1 and (4.7 ± 1.4) × 10 11 dm 6 mol -2 s -1 , respectively . Since no literature value could be found for CFCl 3 quenching of XeCl*, this rate constant was assumed to be equal to the value for CCl 4 , , as previously …”

Photodynamics of charge transfer and ion-pair states of Cl2:Xe complexes in liquid Ar

“…The dielectric of the medium also effects a shortening of radiative lifetimes, such that 1 / g ϳ0.6. 35 Taking this effect into account, using the gas phase radiative lifetimes for B→X and C→A transitions of 13 and 130 ns, respectively, we may conclude from the ob-served lifetime for these states that the ordering between B and C states is the same as in the gas phase, 36 B is above C by ϳ70 cm Ϫ1 . Excitation of the same solution with the sequence 308 nmϩ250 nm leads to the spectrum in Fig.…”

Multiterawatt Hybrid (Solid/Gas) Femtosecond Systems in the Visible

“…Production of Cl atoms is provided by the same pump pulse of the XeCl laser via photodissociation of C1 2 . In the mixtures of Xe and Cl 2 at pressures of 1-2 bar and 1-2 Torr, respectively, the quantum efficiency for the energy transfer from XeCl(B,C) to Xe 2 Cl(4 2 Γ) is close to 100% due to the extremely high rate constant (1.3 × 10 -30 cm 6 s -1 [39]) of the XeCl(B,C) recombination with xenon. The main loss process in the pump mechanism considered here is the C1 2 photodissociation to accumulate a sufficient number of Cl atoms and thereby ensure a high enough absorption of pump photons in the longitudinal geometry of excitation.…”