Efficient Deep Blue Pt(II) Emitters for OLEDs and Push-Pull Boron Functionalized Isomers

Abstract

This thesis describes the development of two distinct types of luminescent materials and the exploration of their photophysical properties. The first part of the thesis focuses on the synthesis of four new deep-blue phosphorescent Pt(II) compounds by introducing side alkyl chains of different length to two reported Pt(II) compounds with tetradentate and macrocyclic chelate ligands, respectively. The employment of a new synthetic pathway leads to higher yield of the products and shorter reaction time. The modified Pt(II) compounds possess improved solubility in organic solvents, similar photophysical properties, and better performance as the deep-blue electrophosphorescent emitters of OLEDs, compared to the corresponding original Pt(II) compounds. In second part of the thesis, a series of fluorescent indolizino[6,5,4,3-def]phenanthridine derivatives were produced by 1,3-dipolar cycloaddition reactions between a new azomethine ylide and eight selected alkynes. All the BPhMes2-functionalized compounds are found to exhibit charge-transfer (CT) fluorescence, while the others exhibit π to π* transitions. Among them, the three pairs of push-pull regioisomers that are formed by reactions with BPhMes2-functionalized asymmetrical internal alkynes are worthy of most attention. They possess distinct electronic and photophysical properties and some of which show rare and interesting temperature “turn-on” fluorescence.