Millimeter Wave Rotational Spectrum and Molecular Constants of 31P14N

Abstract

The rotational spectrum of diatomic phosphorus nitride has been measured in the millimeter and sub‐millimeter wave regions by use of a high temperature, microwave spectrometer. Transitions have been observed in five different vibrational states. From analysis of the data the following Dunham coefficients are obtained: Y₀₁=23578.240(11) MHz, $Y_{11}\text{=−165.976(18)\hspace{0.17em}}\mathrm{MHz}{\mathrm{,\hspace{0.17em}Y}}_{21}\text{=−0.192(9)\hspace{0.17em}}\mathrm{MHz}{\mathrm{,\hspace{0.17em}Y}}_{31}\text{=−7.6(13)\hspace{0.17em}}\mathrm{kHz}$ , and $Y_{02}\text{=−32.70(8)\hspace{0.17em}}\mathrm{kHz}$ . The Dunham potential constants are found to be: $a_0{\text{=5.670(11)× 10}}^5\hspace{0.17em}{\mathrm{cm}}^{\text{−1}}{\mathrm{,\hspace{0.17em}a}}_1\text{=−2.992(2)}$ , a₂=5.7(4), and $a_3\text{=−10(3)}$ . The equilibrium internuclear distance is r_e=1.49086(2) Å.