Vibrational and rotational dependence of the removal of CD(A2Δ, B 2Σ− and C 2Σ+) by H2

Quenching rate constants for several rovibrational levels of the A2Δ, B 2Σ− and C 2Σ+ states of deuterated methylidyne, under collisions with H2, have been measured. In the A2Σ, ν′ = 0 state the rate constants kQ increase with rotational quantum number, from 10 × 10−12 cm3 molecule−1 s−1 for N′ = 11 up to 39.5 × 10−12 cm3 molecule−1 s−1 for N′ = 20. For the A2Δ state the kQ values are not dependent on the vibrational quantum number; the rotationally unresolved emission from A2Δ, ν′ = 0 and 1 is quenched at a rate of 8.5 × 10−12 cm3 molecule−1 s−1, with a similar value for ν′ = 2. For B 2Σ−, ν′ = 0, kQ = 16.2 × 10−12 cm3 molecule−1 s−1, whereas ν′ = 1 is quenched twice as slow. For C 2Σ+, ν′ = 0, kQ = 26.8 × 10−12 cm3 molecule−1s−1.