 In contrast, the boiling points of PhF and benzene are very similar, differing by only 4 °C.It is considerably more polar than benzene, with a dielectric constant of 5.42 compared to 2.28 for benzene at 298 K. Fluorobenzene is a relatively inert compound reflecting the strength of the C–F bond.Although it is usually considered a non-coordinating solvent, a metal complex of PhF has been crystallized.