Neil Bartlett a chemical scientist, was studying the properties of Xenon, at that time he started comparing the ionisation enthalpies of Xenon with other elements. when he compared Ionisation enthalpy of Xenon (1170 kj/mol) with Oxygen (1175 kj/mol) , he found that these are almost identical.
Oxygen on treatment with PtF6 gave O2PtF6 , this lead to idea of discovery of compounds of Xenon.
And he treated Xenon with PtF6 and the reaction took place yielding an orange yellow product.
the first chemical reaction of Xenon is as follows :-