Patent ID: 7311982

Claim:
A monomer which luminesces in the visible region upon excitation having the formula: M n+ (L) n− (CL) x wherein n+ is the valency of M, (L) represents one or more anionic ligands with a total valency of n− such that at least one of the ligands possesses the formula Ch-X—Y wherein Ch represents a chelating group which is a ligand fragment comprising the chelate binding sites and the part of the rest of the ligand with which the binding sites are conjugated, Y represents an olefinic group and X represents a spacer comprising a chain of at least four carbon and/or hetero atoms, x is 0, 1, or 2, CL represents a neutral co-ligand, and M represents a metal atom of group 2, 12, 13, or d-block with the proviso that if Y is part of a styrene or substituted styrene group then M is a d-block metal.