Electroluminescent materials and devices

An electroluminescent compound which has the formula

• where M is a metal selected from metals other than a rare earth metals, a transition metals, a lanthanides or an and actinides;
• n is the valency of M;
• R1, R2 and R3, which may be the same or different are selected from hydrogen, hydrocarbyl groups, substituted and unsubstituted aliphatic groups, substituted and unsubstituted aromatic, heterocyclic and polycyclic ring structures, fluorocarbons such as trifluoryl methyl groups, halogens such as fluorine or thiophenyl groups or nitrile;
• R1 and R3 can also be form ring structures, and R1, R2 and R3 can be copolymerisable with a monomer.