Nanocomposite material made of a polymer-matrix comprising PEO- containing polymers and salts of luminescent polyanionic metal clusters

A solid nanocomposite material consisting of a polymer-matrix in which are dispersed alkali metal, hydronium or ammonium salts of polyanionic metal clusters, wherein the alkali metal, hydronium or ammonium salts of the polyanionic metal clusters are salts or a mixture of salts of the general formula AnM6Xi8La6, wherein:

• A represents Cs, Na, K, a hydronium or NR1R2R3R4, wherein R1 to R4 represent, independently of each other, a hydrogen atom or a C1-C6 alkyl group;
• n ranges from 2 to 5;
• M represents Mo, W or a mixture thereof;
• Xi is an inner ligand and represents a halogen or a chalcogen atom or a mixture thereof;
• and
• La is an apical ligand and represents a halogen atom, an organic ligand or a mixture thereof,
• wherein the polymer-matrix comprises at least a linear or branched polymer or copolymer containing one or several poly(ethylene oxide) (PEO) chains, said polymer or copolymer being optionally crosslinked and each PEO chain having at least 4 ethylene oxide monomer units, and
• wherein the salts of polyanionic metal clusters interact with the polymer-matrix solely by means of weak interactions in between the alkali metal, hydronium or ammonium cation and the PEO chains of polymer or copolymer.