Efficient Synthetic Approaches To Access Ruthenium(II) Complexes with 2‐(Trimethylsilyl)ethyl‐ or Acetyl‐Protected Terpyridine–Thiols

Abstract

AbstractA series of thiol‐functionalized terpyridines (tpy) with protective groups, such as acetyl (Ac), 2‐(trimethylsilyl)ethyl (TMSE), and tert‐butyl (tBu), and the corresponding ruthenium(II) complexes were synthesized in high yields. The TMSE‐protected thiol‐functionalized RuII(tpy) complexes can be readily converted into the corresponding ruthenium(II) complexes with an acetyl group by using AgClO4/acetyl chloride or TBAF/acetyl chloride. Based on this convenient synthetic approach under mild conditions, the ruthenium(II) complex [(AcSCH2C6H4tpy)(PPh3)2Ru(C≡CC6H4C≡CC6H5)](ClO4) {[12](ClO4)} with acetylthio–tpy was successfully obtained by a three‐step synthetic procedure. By utilizing 4′‐{4‐[(acetylsulfanyl)methyl]phenyl}‐2,2′:6′,2″‐terpyridine as a chelating ligand, a dinuclear dicyanamido‐linked ruthenium complex was prepared, characterized, and immobilized onto gold electrode surfaces to form self‐assembled monolayers (SAMs). The compounds were characterized by mass spectrometry, IR, 1H NMR and 13C NMR or 31P NMR spectroscopy, and elemental analysis. The solid‐state structure of complex [14](PF6)3 was determined by X‐ray crystallography, in which the intramolecular S⋅⋅⋅S distance was found to be 31.194(2) Å.