Germanium difluoride (GeF₂) is a chemical compound of

germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors ...

and

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactiv ...

. It is a white solid with a

melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depen ...

of 110 °C, and can be produced by reacting

germanium tetrafluoride Germanium tetrafluoride (GeF4) is a chemical compound of germanium and fluorine. It is a colorless gas. Synthesis Germanium tetrafluoride is formed by treating germanium with fluorine: : Ge + 2 F2 → GeF4 Alternatively germanium dioxide combine ...

with germanium powder at 150–300 °C.

Structure

Germanium difluoride forms orthorhombic crystals with a

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...

P2₁2₁2₁ (No. 19),

Pearson symbol The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure ...

oP12, and lattice constants a = 0.4682 nm, b = 0.5178 nm, c = 0.8312 nm, Z = 4 (four structure units per unit cell). Its crystal structure is characterized by strong polymeric chains composed by GeF₃ pyramids. One of the fluorine atom in the pyramid is shared by two neighboring chains, providing a weak link between them. Another, less common crystal form of GeF₂ has tetragonal symmetry with a space group P4₁2₁2 (No. 92),

tP12, and lattice constants a = 0.487 nm, b = 0.6963 nm, c = 0.858 nm.

References

{{Fluorides Fluorides Metal halides Germanium(II) compounds