(Spectro)electrochemical Properties of Anthracene Containing Triarylamine Platinum(II) Acetylides

The synthesis of [Pt{ 2 } 2 (PPh 3 ) 2 ] ( 5 ) (10‐ethinyl‐9‐di( p ‐anisyl)aminoanthracene=alkyne 2 H) in a cis and trans configuration was achieved. Adsorption of cis ‐ 5 on AlOx as well as electrochemical oxidation led to a reductive elimination of 10,10′‐(buta‐1,3‐diyne‐1,4‐diyl)bis(9‐di( p ‐anisyl)amino‐anthracene) ( 6 ). The molecular structures of the alkyne intermediate 2 H, [Pt{ 2 }Cl(PPh 3 ) 2 ] ( 4 ) and butadiyne 6 have been determined by single crystal X‐ray diffraction. Cyclic voltammetry measurements of the platinum‐acetylides trans‐ 4 , and cis‐ and trans ‐ 5 demonstrated, that the back donation from platinum towards the π ‐system results in a shift of the triarylamine and anthracene related redox processes towards lower E °′ values, when compared to the SiMe 3 ‐protected alkyne of 2 (= 2 SiMe 3 ). Both platinum complex trans ‐ 5 and butadiyne 6 demonstrated that the individual arylamine and the respective anthracenyl buildings blocks can be oxidized in four one electron processes. Spectroelectrochemical studies revealed several intense intra‐ligand absorptions in the NIR, demonstrating a high degree of delocalization in the ligand. However, a direct IVCT through the platinum was not observed.