Synthesis of IrIII Hydrido Complexes by Oxidative Addition of Halogenated Theophylline and Adenine Derivatives

Jonas Blumenberg; Florian Kampert; Alexander Hepp; F Ekkehardt Hahn

doi:10.1021/acsomega.0c02290

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

ACS Omega. 2020 Jun 29;5(27):16951-16958. doi: 10.1021/acsomega.0c02290. eCollection 2020 Jul 14.

Authors

Jonas Blumenberg¹, Florian Kampert¹, Alexander Hepp¹, F Ekkehardt Hahn¹

Affiliation

¹ Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 28/30, 48149 Münster, Germany.

Abstract

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 PPh₃. 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 PPh₃ 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.