 The differing structures reflects the greater tendency of chlorine to exist in positive oxidation states with oxygen and fluorine ligands.The related Cl-O-F compound perchloryl fluoride, ClO3F, is tetrahedral.The related bromine compound "bromyl fluoride" (BrO2F) adopts the same structure as ClO2F, whereas "iodyl fluoride" (IO2F) forms a polymeric substance under standard conditions.