Transition metal complexes and ligand design for organic optoelectronics
FacultiesFakultät für Naturwissenschaften
A variety of chelating N^N ligands has been synthesized using the CuAAC (click) reaction, either to functionalize the periphery of the ligand or to use the resulting triazole moiety as a part of the chelate. In most cases, the reaction met the demands of click chemistry and proved to be a versatilely applicable method in order to synthesize and to modify platinum(II) and ruthenium(II) complexes with chelating ligands. A comprehensive series of substituted bpyPt(II) bisacetylides (bpy = 2,2’-bipyridine) was synthesized and post-functionalized with different azides via click chemistry. The photophysical and electrochemical properties were investigated. The click reaction resulting in 1,2,3-triazoles as bridging moieties constitutes a versatile and adequate method for the post-functionalization of Pt(II) complexes, both from synthetic and photophysical viewpoints. This opens the possibility to covalently link Pt(II) emitters to surfaces, polymers or other molecular scaffolds, without diminishing their emissive properties. Thus, the strategy has been applied in the synthesis of dinuclear Pt(II) compounds. Four dimeric complexes bearing different flexible linker moieties have been synthesized and characterized. It has been shown that intramolecular Pt(II)-Pt(II) interactions in those flexibly linked dimers can be used to tune the emission colour of the compounds. A red-shift of the emission can be influenced by the choice of the solvent. Aiming at a dinuclear Pt(II) complex in which the intramolecular interactions of the bpyPt(II) moieties can be switched on and off in a controllable mechanism, a crownophane backbone molecule was designed as a linker and synthesized in a multi-step approach. The click approach was further applied in the synthesis of new chelating ligands for Ru(II) sensitizers in dye-sensitized solar cells (DSSC).
Subject HeadingsClick-Chemie [GND]
Organic electronics [LCSH]