What inspired $N. \ Bartlett$ to carry out the reaction between $Xe$ and $PtF_6$?

(N/A) $Neil \ Bartlett$ initially carried out a reaction between oxygen $(O_2)$ and $PtF_6$. This resulted in the formation of a red compound,$O_2^+ [PtF_6]^-$.
Later,he realized that the first ionization energy of oxygen $(1175 \ kJ \ mol^{-1})$ and $Xe$ $(1170 \ kJ \ mol^{-1})$ is almost the same.
Thus,he hypothesized that if $O_2$ could react with $PtF_6$,$Xe$ should also react with $PtF_6$. He was successful,and a red-coloured compound,$Xe^+ [PtF_6]^-$,was formed.