Advantages of including metal ions in liquid crystal systems

When a metal ion is introduced in a liquid crystal system there are several factors which can influence the properties of such a system: the mobility of electron density on metal, the presence of unpaired electrons and, of course, the colour.

Colour – This is the most obvious property given by metal complexes. Colourless liquid crystal materials and filters to produce the desired colours are still used in building colour TV monitors.

Polararisability – It is well-known that the metal ions have a polarisable electron density and the birefingence and the dielectric constants depend on polarisability and even it was proven that the thermal stability of liquid crystalline phases depend, in some extent, on polarisability.

Magnetism – feromagnetic systems are extensively studied, but there are few perspectives in using paramagnetic systems to influence the switching time, mostly due to the spin that can be regarded as being isotropic in such systems.

Structural factor – inclusion of metal ions in organic systems produces new structures by their ability to adopt different coordination geometries leading to new properties, which are not specific to simple pure organic systems.