Knowledge Bank

A new sequence ($\Delta$v = 0, v = 0 to v = 13) of a $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi -1\Sigma$ band system attributed to the AsF molecule has been observed in a microwave discharge through flowing $AsF3$ vapour. Rotational analysis of the 0 --- 0 and 1 --- 1 bands suggests that the lower state is the previously known b $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +$ state. The rotational constants obtained for the new $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi$ state are $${B}{v} = 0.3737 - 0.0029 ({v} + \frac{1}{2})\mbox{cm}^{-1}$$ $${D}{v} = 4.2 + 0.03 (v + \frac{1}{2})\mbox{ cm}^{-1}$$ $${q}{v-0} = q{v-1} = 0.0017 \mbox{cm}^{-1}$$