Knowledge Bank

Emission spectra of GeF, excited in a discharge in flowing $GeF4$ vapour, have been photographed under high resolution, and rotational analyses have been carried out for various sub-bands of the A-X and B-X systems. The principal molecular constants for $\mathrm{<mrow\; data-mjx-texclass="ORD">74</mrow>}GeF$ are as follows: $(cm-1$, except $re$) \begin{tabular}{@{}llllll@{}} & $T0$ &$\Delta G1/2$ &$Be$ &$\alpha e$ & $re$\ $B2\Sigma +$ & 35076.3 & 789.9 & 0.3938 & 0.0020 & 1.683 {\AA}\ $A2\Sigma +$ & 23190.84 &410.75 & 0.32033 & 0.00299 & 1.8660\ X $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi 3/2$& 935.16 & 661.07 & 0.36657 & 0.00266 & 1.7443\ $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi 1/2$ & 0.00 & 659.42 & 0.36575 & 0.00266 & 1.7463\ \end{tabular} The states A and X are in the relationship of pure precession, with $\gamma (A2\Sigma )$ and p $(X2\Pi 1/2)$ being of similar magnitude. The B-X system overlaps and interacts with a newly-discovered system of weak red-degraded bands; because of the complicated Ge isotope structure it has not been possible to analyze the interactions in detail, but experiments with separated $\mathrm{<mrow\; data-mjx-texclass="ORD">74</mrow>}GeF$ are in progress, which, it is hoped, will clarify the patterns. The new state seems to be a case (b)$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ state, though $\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}\Sigma -$ cannot be ruled out.