What inspired N. Bartlett for carrying out reaction between

Neil Bartlett initially carried out a reaction between oxygen and $\mathrm{PtF}_{6}$. This resulted in the formation of a red compound, $\mathrm{O}_{2}^{+}\left[\mathrm{PtF}_{6}\right]^{-}$.

Later, he realized that the first ionization energy of oxygen ( $1175 \mathrm{~kJ} / \mathrm{mol}$ ) and $\mathrm{Xe}(1170 \mathrm{~kJ} / \mathrm{mol})$ is almost the same. Thus, he tried to prepare a compound with $\mathrm{Xe}$ and $\mathrm{PtF}_{6}$. He was successful and a red-coloured compound, $\mathrm{Xe}^{+}\left[\mathrm{PtF}_{6}\right]^{-}$was formed.