Nanocomposite Dendrimers Based on Cyclic Phosphazene Cores: Amorphous Materials for Electroluminescent Devices

Abstract

Abstract Summary: A new family of solution‐processable, photoluminescent, nanocomposite dendrimers based on cyclic phosphazene (CP) cores have been prepared and characterized. The synthetic approach is based on the preparation of bromoaromatic‐functionalized CP cores by reacting selected bromophenolic compounds with the commercially available hexachlorocyclotriphosphazene in yields >90%. The bromophenyl‐functionalized CP cores are then reacted with N ‐ p ‐tolylpyren‐1‐amine using Buchwald‐Hartwig amination chemistry to give the dendrimers of interest in yields >90%. The resultant dendrimers have high glass transition (>165 °C) and decomposition temperatures (>465 °C), are monodisperse (PDI < 1.05), have high purity via common chromatographic techniques, have high photoluminescent quantum efficiencies (83%), and form defect‐free amorphous films via spin/dip coating. A comparison to their molecular analogues is also provided to demonstrate the superior properties of the new nanocomposite dendrimers. Structure of the cyclic phosphazene dendrimers. magnified image Structure of the cyclic phosphazene dendrimers.