The Infrared Spectrum and Molecular Constants of DBr

Abstract

High‐dispersion measurements have been made for the first time on the fundamental, first overtone, and second overtone infrared vibrational bands of DBr. Path lengths from 40 cm to 17 m were used with pressures ranging from 90 mm to 460 mm. The isotopic splitting of the rotation lines was measured and molecular constants determined for both isotopic species, DBr⁷⁹ and DBr⁸¹. The principal constants for DBr⁷⁹ are ${\omega }_e\text{=1885.33\hspace{0.17em}}\mathrm{K}{\mathrm{,x}}_e{\omega }_e\text{=22.73\hspace{0.17em}}\mathrm{K}{\mathrm{,y}}_e{\omega }_e\text{=−0.0106\hspace{0.17em}}\mathrm{K}{\mathrm{,B}}_e{\text{=4.290}}_8\hspace{0.17em}\mathrm{K}{\mathrm{,\alpha }}_e{\text{=0.083}}_9\hspace{0.17em}\mathrm{K}{\mathrm{,D}}_e{\text{=9.6}}_4{\text{×10}}^{\text{−5}}\hspace{0.17em}\mathrm{K}{\text{,β=−2}}_{\text{·2}}{\text{×10}}^{\text{−6}}\hspace{0.17em}\mathrm{K}$ . The principal constants for DBr⁸¹ are ${\omega }_e\text{=1884.75\hspace{0.17em}}\mathrm{K}{\mathrm{,x}}_e{\omega }_e\text{=22.72\hspace{0.17em}}\mathrm{K}{\mathrm{,y}}_e{\omega }_e\text{=−0.0106\hspace{0.17em}}\mathrm{K}{\mathrm{,B}}_e{\text{=4.287}}_6\hspace{0.17em}\mathrm{K}{\mathrm{,\alpha }}_e{\text{=0.083}}_8\hspace{0.17em}\mathrm{K}{\mathrm{,D}}_e{\text{=9.5}}_9{\text{×10}}^{\text{−5}}\hspace{0.17em}\mathrm{K}{\text{,β=−2}}_{\text{·2}}{\text{×10}}^{\text{−6}}\hspace{0.17em}\mathrm{K}$ .