Synthesis, electrochemistry, and optical properties of half-sandwich ruthenium complexes bearing triarylamine-anthracenes

The complex [CpRu^II(dppe)(taae)] {Cp = η⁵-C₅H₅, dppe = 1,2-(PPh₂)₂-C₂H₄, taae = 10-ethynyl-N,N-di-p-tolylanthracen-9-amine} has been synthesized in a multistep reaction protocol including Sonogashira C,C- and Buchwald-Hartwig C,N- cross coupling reactions. Electrochemical and spectroscopic studies suggest a high degree of delocalization between the ruthenium and triarylamine termini through the anthracene bridge, forming a donor-π-acceptor (D-π-A) dye whose π-π* transitions exhibit charge-transfer character in the monocationic oxidation state. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)