sentences:  He was the first to establish the law governing the broadening of quadripolar nuclear resonance in crystals containing isomorphic impurities.In this way he discovered the effects of charge transfer, the fraction of the transfer and the location of the transferred electron.From 1957 he concentrated on the properties of nitrogen and presented his findings to the Academy as "La molécule de N2O4 et un nouveau type de liaison chimique" "("The N204 molecule and a new type of chemical bond")"
  
  In 1964, free radicals in various meteorites were identified at Liege.