In March 1962, Neil Bartlett, then at the University of British Columbia, observed the reaction of a noble gas. First, he prepared a red compound which is formulated as O2[PtF6]− and it is already know that the first ionisation enthalpy of molecular oxygen (1175kJmol−1) is almost similar with that xenon (1170kJmol−1). Then he made efforts to prepare same type of compound by mixing PtF6 and Xenon Xe+[PtF6]−. After this discovery, a number of xenon compounds mainly with most electronegative elements like fluorine and oxygen, have been synthesised.