Tunable Organophosphorus Dopants For Bright White Organic Light-emitting Diodes With Simple Structures

摘要

Research on the development of new emissive π-conjugated oligomers and polymers for different technological applications such as organic light-emitting diodes (OLEDs), including white organic light-emitting diodes (WOLEDs), is very active. In this area, a particularly powerful strategy that has evolved for diversifying the properties and expanding the function of classical π-conjugated systems involves the incorporation of reactive heteroatoms into the conjugated chain. Building blocks that are particularly amenable to this approach are phospholes, since they possess nucleophilic phosphorus centers, thus allowing direct access to a range of novel π-conjugated systems with diverse optical and electrochemical properties. For example, chemical modification of the P atom of the mixed phosphole-thiophene oligomer 2a affords derivatives 3a and 4a (Scheme 1), which exhibit improved thermal stability, red-shifted photoluminescence (PL) emissions, and higher reduction/ oxidation potentials than the unmodified phospholes.