F number is a number used in the chemistry of polycyclic aromatic hydrocarbons (PAHs) as a descriptor of their molecular size. It was proposed by R.J. Hurtubise et al in 1977.
Contents
Calculation
From a PAH it can be calculated using the formula: F = B2 + C12 - R / 2,
where B2 is the number of double bonds C12 is the number of primary and secondary carbons R is the number of non-aromatic rings.Example
For fluorene, the F number is: F = 6 + 1 - 0.5 = 6.5.
Correlation
It has been found that the F number linearly correlates with the log k' value (logarithm of retention factor) in aqueous reversed-phase liquid chromatography.
References
F number (chemistry) Wikipedia(Text) CC BY-SA