Microwave-Assisted Synthesis of an Alternant Poly(fluorene-oxadiazole). Synthesis, Properties, and White Light-Emitting Devices.

ABSTRACT: An alternant poly(dihexyl fluorene-co diphenyl oxadiazole) has been synthetized by microwave-assisted oxidative polymerization. The structure has been confirmed by 1H-NMR and FTIR spectroscopies. Gel permeation chromatography indicated high molecular weight and low polydispersity index. DFT calculations suggested a complete separation of HOMO and LUMO orbitals, which were located on fluorene and oxadiazole moiety, respectively. X-ray diffraction, polarized light microscopy, and atomic force microscopy indicated the polymer tendency to stack into a layered morphology with a more compact structure for the films prepared by spin coating. Furthermore, UV-vis and photoluminescence spectroscopies indicated the formation of H-aggregates which played a key role in photoluminescence quenching in solid state. Nevertheless, the good charge mobility gained due to the orbital overlapping in H-aggregates led to excellent electroluminescence, which enabled the development of white OLED devices with outstanding stability.

SUBMITTER: Popovici D 

PROVIDER: S-EPMC6835352 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature