Smart-responsive Phosphorescent Transition-metal Complexes: Design, Synthesis And Optoelectronic Properties

Cyclometalated Iridium(III)–Polypyridine Complexes have received considerable attention due to their excellent photophysical properties, such as high emission efficiencies and easy tuning of emission colors by changing chemical structures of ligands. Phosphorescent iridium(III) complexes have been widely applied in organic electronic memory devices, chemical sensors, bio-imaging and so on. This dissertation is comprised of the following two parts.1. A series of charged diiminoiridium complexes [Ir(ppy)2(qpyMe2)](PF6)3, [Ir(pq)2(qpyMe2)](PF6)3 and [Ru((bpy)2(qpyMe2)](PF6)4 were prepared, where ppy is 2-phenylpyridine and pq is 2-phenylquinoline, N^N are bidentate N-coordinating ligands: 2,2’-bipyridine. All of the complexes were characterized by 1 H NMR, MALDI-TOF. Photophysical and electrochemical properties of these complexes were investigated and the complexes showed different optoelectronic properties. Through a rational molecular design, adjust the structure of complex molecules,Viologen structures as N^N ligand was introduced in the transition metal iridium complex improving the sensitivity of complexs to heat and electric field due to their excellent redox.2. A series of the Dual-emissive properties of cyclometalated iridium(III)–polypyridine complexes were prepared. dual emission is not uncommon for iridium(III)–polypyridine com plexes and very rare in fluid solutions under ambient conditions. The complexes [Ir(ppy-CH2-R)2(bpy-CONH-C2H5)](PF6)(R=H(Ir1), NH2(Ir2), NHC4H9(Ir3), piperidine(Ir4)). At roo m temperature, the complex Ir3 and Ir4 showed dual emission in fluid solutions. the ratiod etection can detect the intensity of the two light signals in different wavelengths, which can reduce the impact of environmental factors We believe that an attractive approach to the d evelopment of new iridium-(III)-based luminescent probes would be the utilization ofnovel c omplexes that display environment-responsive dual-emissive properties.