Millimeter and Submillimeter Wave Spectrum and Molecular Constants of Aluminum Monofluoride

Rotational transitions of ²⁷Al¹⁹F have been measured in the millimeter and submillimeter wave regions to frequencies of 461 Gc/sec. Vibrational states up to $\text{υ\hspace{0.17em}=\hspace{0.17em}4}$ were observed. From analysis of the data the following Dunham rotational constants were obtained: $Y_{01}\text{\hspace{0.17em}=\hspace{0.17em}16 562.930\hspace{0.17em}±\hspace{0.17em}0.006}\mathrm{Mc}/\sec$ , $Y_{11}\text{\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}149.420\hspace{0.17em}±\hspace{0.17em}0.009}\mathrm{Mc}/\sec$ , $Y_{21}\text{\hspace{0.17em}=\hspace{0.17em}0.515\hspace{0.17em}±\hspace{0.17em}0.004}\mathrm{Mc}/\sec$ , $Y_{31}\text{\hspace{0.17em}=\hspace{0.17em}1.4\hspace{0.17em}±\hspace{0.17em}0.6}\mathrm{kc}/\sec$ , $Y_{02}\text{\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}31.37\hspace{0.17em}±\hspace{0.17em}0.02}\mathrm{kc}/\sec$ , and $Y_{12}\text{\hspace{0.17em}=\hspace{0.17em}0.046\hspace{0.17em}±\hspace{0.17em}0.014}\mathrm{kc}/\sec$ . The Dunham potential constants found are: $a_0{\text{\hspace{0.17em}=\hspace{0.17em}2.9167\hspace{0.17em}±\hspace{0.17em}0.0019\hspace{0.17em}×\hspace{0.17em}10}}^5$ , $a_1\text{\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}3.1850\hspace{0.17em}±\hspace{0.17em}0.0009}$ , $a_2\text{\hspace{0.17em}=\hspace{0.17em}6.82\hspace{0.17em}±\hspace{0.17em}0.06}$ , and $a_3\text{\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}11.6\hspace{0.17em}±\hspace{0.17em}0.6}{\mathrm{cm}}^{\text{−1}}$ . The nuclear quadrupole coupling constants obtained are: ${\mathrm{eqQ(}}^{27}\mathrm{Al}\text{)\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}37.59\hspace{0.17em}±\hspace{0.17em}0.25}\mathrm{Mc}/\sec$ for $\text{υ\hspace{0.17em}=\hspace{0.17em}0}$ and ${\mathrm{eqQ(}}^{27}\mathrm{Al}\text{)\hspace{0.17em}=\hspace{0.17em}−\hspace{0.17em}37.14\hspace{0.17em}±\hspace{0.17em}0.6}\mathrm{Mc}/\sec$ for the $\text{υ\hspace{0.17em}=\hspace{0.17em}1}$ vibrational state. Vibrational constants derived are ${\omega }_e\text{\hspace{0.17em}=\hspace{0.17em}802.85\hspace{0.17em}±\hspace{0.17em}0.25}{\mathrm{cm}}^{\text{−1}}$ and ${\omega }_e{x}_e\text{\hspace{0.17em}=\hspace{0.17em}4.86\hspace{0.17em}±\hspace{0.17em}0.06}{\mathrm{cm}}^{\text{−1}}$ . The equilibrium internuclear distance $r_e\text{\hspace{0.17em}=\hspace{0.17em}1.65436\hspace{0.17em}±\hspace{0.17em}0.00002 Å}$ was obtained.