Lanthanide complexes conjugated polymers

Although the studies on OLEDs have achieved considerable success, it is still difficult to obtain pure emission colors from small organic molecules or conjugated polymers, because their emission spectra typically have a half peak width of about 100 nm. Lanthanide ions can exhibit spectrally narrow emission due to intra-atomic transitions within the 4f shell. Consequently, luminescent lanthanide complexes are good candidates as emitting materials in OLEDs. 

Two kinds of salen-type Schiff-base ligands, conjugated and flexible, have been used in the synthesis of polynuclear lanthanide complexes and lanthanide coordination polymers Lanthanides Coordination Chemistry, Rare Earth Metal Cluster Complexes. The stoichiometry and structures of these complexes are dependent on the Schiff-base... 

---