ABSTRACT
The IrIII hydrido complexes [1] and [2] have been synthesized by the regioselective oxidative addition of the N7-H bond of 8-halogenotheophyllines to [IrCl(coe)2]2 in the presence of PPh3. The use of dppf in this reaction yielded the bimetallic IrIII/FeII hydrido complexes [3] and [4]. X-ray diffraction studies confirmed that complexes [1]-[4] feature a theophyllinato ligand coordinated to the metal center in the rarely observed, chelating fashion via the N7 and O1 atoms. In addition, 8-bromoadenine reacts with [IrCl(coe)2]2 in the presence of PPh3 to form the IrIII hydrido complex [5] which features one anionic 8-bromoadeninato and one neutral 8-bromoadenine ligand linked by an intramolecular hydrogen bond. Complex [5] was characterized by high-resolution mass spectrometry and an X-ray diffraction analysis but could not be analyzed by nuclear magnetic resonance spectroscopy because of its low solubility.
ABSTRACT
An imidazolium/2-chlorobenzimidazole bis-NHC precursor has been reacted with Ag2O followed by transmetallation with [AuCl(THT)] to give the Au-NHC complex via metallation of the imidazolium site, while the reaction of the same bis-NHC precursor with [Pd(PPh3)4] yields exclusively the azolato complex by oxidative addition of the C2-Cl bond to Pd0. Both complexes have been converted into the heterobimetallic Au/Pd-complex by reaction with [Pd(PPh)3]4 (for the NHC complex) or Ag2O/[AuCl(THT)] (for the azolato complex), respectively.
