Knowledge Bank

If a mixture of $NF3$ and Ar is pumped rapidly through a mild discharge, the gas emits a green afterglow which extends several centimeters beyond the discharge. This green glow has been photographed at high dispersion with a ten meter concave grating spectrograph and found to consist of one strong band and several weaker bands. The strong band has a prominent Q head at $5288\backslash AA$. An analysis of the rotational and vibrational structure of the band system shows that it is the $b1\Sigma +-X3\Sigma -$ system of the NF molecule. The ground state bond distance and vibrational frequency are found to be $re=1.317\backslash AA$ and $\omega e=1141.36cm-1$. Permanent address of W. E. Jones: Chemistry Department, Dalhousie University, Halifax, Nova Scotia, Canada.