Calculation F number (chemistry)

fluorene

for fluorene, there 6 apparent double bonds (three pi bonds in each side benzene-like ring); central ring has 1 secondary carbon , non-aromatic. therefore:

f
=
6
+
1
−


1
2


1
=
6.5


{\displaystyle f=6+1-{\frac {1}{2}}1=6.5}