A difluorine complex is a molecular coordination complex involving a difluorine (F<sub>2</sub>) group as a ligand. The first example was gold heptafluoride (AuF<sub>7</sub>). Instead of being a gold(VII) compound, with all five fluorine atoms equally bonded to the central gold atom, the structure is an adduct of gold(V) fluoride (AuF<sub>5</sub>) and F<sub>2</sub>. This conclusion has been repeatedly supported by calculations.
Although other diatomic element complexes exist, difluorine complexes have a different hapticity. Dinitrogen complexes of main-group elements and dihydrogen complex feature a "side-on" bonding of the hydrogen group with both hydrogen atoms participating in the coordinate bonding (÷<sup>2</sup>-H<sub>2</sub>), whereas difluorine complexes feature "end-on" bonding with only one of the two fluorine atoms participating in the coordinate bonding (÷<sup>1</sup>-F<sub>2</sub>).