Facile Synthesis of 1,7-Phenanthroline Derivatives and Evaluation of Their Properties as Hole-Blocking Materials in Organic Light-Emitting Diodes

Abstract

Abstract Phenanthroline derivatives are typical simple aza-polycyclic aromatic hydrocarbons that have been used as hole-blocking and electron-transporting materials in organic light-emitting diodes (OLEDs). In contrast to the widely used 1,10-phenanthroline derivatives, other isomers, including 1,7-phenanthrolines, have been explored less, partly due to the lack of effective and selective synthesis methods. This study demonstrates the facile synthesis of 1,7-phenanthroline derivatives bearing various substituents via a multicomponent reaction based on the aza-Diels-Alder reaction. By investigating the correlation between the substituents and their performance as hole-blocking materials in OLEDs, we gained insight into the molecular design of 1,7-phenanthroline derivatives for material applications.