Fluorobenzene

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.

Structure of fluorobenzene
Structure of fluorobenzene
Space-filling model of fluorobenzene
Space-filling model of fluorobenzene
NFPA 704 four-colored diamond Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentine Flammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasoline Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen Special hazards (white): no code
Structure of [(C 5 Me 5 ) 2 Ti(FC 6 H 5 )] + , a coordination complex of fluorobenzene.