Dissociation Energy of NO andN2

The vibrational levels of the $X{}_{}{}^2{}_{}{}^{}\pi$ ground state of NO have been observed up to $v=23\mathrm{}$, or an energy of 4.46 ev. In order that $D_0\left(\mathrm{NO}\right)$ be 5.29 ev, a very sharp and sudden drop in the $\Delta G\left(v\right)\mathrm{}$ values is necessary. No such tendency is observed, and therefore the higher value of $D_0\left(\mathrm{NO}\right)=6.48\mathrm{}$ ev appears most probable. This value then fixes $D_0\left({\mathrm{N}}_2\right)=9.76\mathrm{}$ ev. A new system of NO bands in the near infrared is reported. These are probably due to a ${}_{}{}^4{}_{}{}^{}\pi \to {}_{}{}^4{}_{}{}^{}\pi$ transition.