Finally , the clue is found not in the nature of the non-fluorine substituent , but in the fluorines themselves .
In all cases , a 1 , 4 - disubstituted - 2 , 3 , 5 , 6 - tetrafluorobenzene derivative shows up .
The clue is found not in the nature of the non-fluorine substituent , but in the fluorines themselves .
In all cases , a 1 , 4 - disubstituted - 2 , 3 , 5 , 6 - tetrafluorobenzene derivative shows up .