Molecular design of optoelectronic structures based on carbazole- and indolocarbazole-containing polyphenylquinolines

Abstract

In this study, the molecular design of synthesized polymeric polyphenylquinoline (PPQ) structures is associated with the varying chemical nature of the bridging group ( X) between the phenylquinoline cycles and the heteroarylene radicals ( Ar) in the repeating unit of PPQs. The photophysical study of optical, photosensitive, and luminescent properties of the PPQs was carried out for isolated macromolecules in solution and interacting molecules in films while varying their intermolecular interactions for PPQ molecules in different matrices. The matrix isolation method we used made it possible to minimize intermacromolecular interactions whose enhancement in coatings leads to an efficient luminescence quenching. To separate the processes of intramolecular and intermacromolecular energy transfer, we studied the photoluminescence from mixtures of PPQ homopolymers. The analysis of ionization potentials for the molecular structures of Ar moieties ( IDAr) and a bridging group X ( IDX) of synthesized PPQs, as well as of copolymers containing carbazole and indolo[3,2-b]carbazole moieties, is given. This analysis based on the study of optical properties (absorption, photosensitivity, luminescence) and electrical characteristics for PPQ led to recommendations on PPQ promising structures for use in optoelectronic devices.