Diruthenium(II)diacetylide organometallic complexes with thienylethynyl bridging units: Synthesis, characterization and electrochemical properties
摘要
A series of soluble diruthenium(II)diacetylide complexes (M1-M3) by varying thienlylethynyl bridging ligands have been achieved by treating the appropriate thienylethynyl spacers (B1, B2 and B3 with one, two and three units of thienylethynyl respectively) with [Ru(dppe)Cp*Cl] and KF in THF/MeOH medium. The synthesized diruthenium(II) organometallic complexes have been thoroughly characterized by multinuclear NMR spectroscopy, FTIR and mass spectrometry. The photophysical and electrochemical studies of these soluble wire-like Ru(II) organometallic complexes (M1-M3) with aromatic π-extended bridges have been carried out to comprehend the electronic and electrochemical properties. The electronic delocalization in Ru(II)–C≡C–Ar–C≡C–Ru(II) (Ar = aromatic bridging ligand) conjugate through the bridging backbone is dependent on the bridging spacers. Potential difference (ΔE1/2) and comproportionation constant (Kc) decrease with increasing the length of the thienylethynyl unit. The mixed-valence species, generated by single-electron oxidation, exhibits absorption in the near-infrared (NIR) region. Moreover, FTIR studies also reveal a change in
Electrochemical and electronic properties of the diruthenium(II)diacetylide organometallic conjugates have been modulated by varying the number of thienylethynyl bridging units.