American Chemical Society
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Heterotrimetallic M−M′−M′′ Transition Metal Complexes Based on 1,3,5-Triethynylbenzene: Synthesis, Solid State Structure, and Electrochemical and UV−Vis Characterization. EPR Analysis of the in Situ Generated Associated Radical Cations

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journal contribution
posted on 2008-07-28, 00:00 authored by Rico Packheiser, Petra Ecorchard, Tobias Rüffer, Manja Lohan, Björn Bräuer, Frédéric Justaud, Claude Lapinte, Heinrich Lang
The synthesis of a series of complexes with different organometallic building blocks unsymmetrically arranged around the periphery of a 1,3,5-triethynylbenzene core is discussed. They are accessible by diverse consecutive reaction sequences, which allow the introduction of transition metal units such as Fc, [(tBu2bpy)(CO)3Re], [(η5-C5H5)(Ph3P)2Ru], [(η5-C5H5)(Ph3P)2Os], and trans-[(Ph3P)2(Cl)Pt] (Fc = (η5-C5H5)(η5-C5H4)Fe; tBu2bpy = 4,4′-di-tert-butyl-2,2′-bipyridyl). The solid state structures of five complexes have been determined. The electrochemical behavior of the newly synthesized mono-, heterobi-, and heterotrimetallic assemblies have been studied, showing that there is no significant electronic interaction between the respective metal atoms. UV−vis spectroscopic measurements suggest a weak interaction between the appropriate metal atoms. The associated radical cations were in situ generated by stepwise chemical oxidation and characterized by continuous wave electron paramagnetic resonance (EPR) investigations in X-band performed at low temperatures.