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 O 2 + [PtF 6 ] – and it is already know that the first ionisation enthalpy of molecular oxygen (1175 kJ mol –1 ) is almost similar with that xenon (1170 kJ mol –1 ). Then he made efforts to prepare same type of compound by mixing Pt F 6 and Xenon Xe + [PtF 6 ] – . After this discovery, a number of xenon compounds mainly with most electronegative elements like fluorine and oxygen, have been synthesised.