High-resolution infrared study of the ν 1 and ν 3 bands, and the equilibrium structure of AsD 3

Abstract

The infrared spectrum of the AsD 3 molecule has been measured in the region of the stretching fundamental bands on a Fourier transform spectrometer with a resolution of 0.0027 cm −1 and analyzed for the first time. More than 3300 normally allowed and in addition more than 900 forbidden, but perturbation-allowed transitions with J max upper = 28 have been assigned to the bands ν 1 and ν 3. An effective Hamiltonian was used which takes into account the resonance interactions between the states (1000) and (0010). A set of 50 (26 diagonal and 24 resonance) refined spectroscopic parameters was obtained from the fit which reproduces the 1229 initial ‘experimental’ upper state ro-vibrational energies with an rms deviation of 0.00024 cm −1. The transition moment ratio | μ 1: μ 3| was determined to be 1.2±0.05, and the intensity perturbation μ 1 ξ 13 y μ 3 found to be negative. The equilibrium values of the bond length r As – D e = 1.51130 ( 11 ) Å and interbond angle α D – As – D e = 92.0775 ( 40 ) ˚ were determined from the values of the rotational parameters of the ground state and the four fundamental bands.