Borides

Borides All of the lanthanides form a number of borides.

Boron nitride binds well with metals, due to formation of interlayers of metal borides or nitrides.

Collectively these are then termed the rare earth borides.

However, the product is almost always contaminated with borides of those metals.

Magnesium(II) ions lie between layers Binary metal-boron compounds, the metal borides, contain boron in negative oxidation states.

Many borides and allotropes of boron contain boron B 12 icosahedron as a basic structure unit.

Other complex higher borides LnB 50 (Tb, Dy, Ho Er Tm Lu) and LnB 25 are known (Gd, Tb, Dy, Ho, Er) and these contain boron icosahedra in the boron framework.

Single crystals of the higher borides have been grown in a low melting metal (e.g. Sn, Cu, Al).

The range of borides formed by the lanthanides can be compared to those formed by the transition metals.