Synthesis of Ir(III) Hydrido Complexes by Oxidative Addition of Halogenated Theophylline and Adenine Derivatives

[Image: see text] The Ir(III) 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 PPh(3). The use of dppf in this reaction yielded the bimetallic Ir(III)/Fe(II) 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 PPh(3) to form the Ir(III) 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.