PhF was first reported in 1886 by O. Wallach at the University of Bonn, who prepared the compound in two steps.

Phenyldiazonium chloride was first converted to a triazene using piperidine: The triazine was then cleaved with hydrofluoric acid: Historical note: in Wallach's era, the element fluorine was symbolized with "Fl".

[1] On the laboratory scale, PhF is prepared by the thermal decomposition of the benzenediazonium tetrafluoroborate: According to the procedure, solid [PhN2]BF4 is heated with a flame to initiate an exothermic reaction, which also affords boron trifluoride and nitrogen gas.

The initially formed cyclopropane undergoes a ring expansion and subsequent elimination of hydrogen fluoride.

PhF behaves rather differently from other halobenzene derivatives owing to the pi-donor properties of fluoride.