Pyrimidoquinazolinophenanthroline Opens Next Chapter in Design of Bridging Ligands for Artificial Photosynthesis. Issue 51 (26th July 2022)

• Record Type: Journal Article
• Authors: Brückmann, Jannik; Müller, Carolin; Maisuradze, Tamar; Mengele, Alexander K.; Nauroozi, Djawed; Fauth, Sven; Gruber, Andreas; Gräfe, Stefanie; Leopold, Kerstin; Kupfer, Stephan; Dietzek‐Ivanšić, Benjamin; Rau, Sven
• Is Part Of: Chemistry. Volume 28:Issue 51(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-26
• Subjects: artificial photosynthesis -- bridging ligand -- light-induced redox catalysis -- quantum chemistry -- ruthenium photosensitizer; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202200766
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The synthesis and detailed characterization of a new Ru polypyridine complex containing a heteroditopic bridging ligand with previously unexplored metal‐metal distances is presented. Due to the twisted geometry of the novel ligand, the resultant division of the ligand in two distinct subunits leads to steady state as well as excited state properties of the corresponding mononuclear Ru(II) polypyridine complex resembling those of prototype [Ru(bpy)3 ] 2+ (bpy=2, 2'‐bipyridine). The localization of the initially optically excited and the nature of the long‐lived excited states on the Ru‐facing ligand spheres is evaluated by resonance Raman and fs‐TA spectroscopy, respectively, and supported by DFT and TDDFT calculations. Coordination of a second metal (Zn or Rh) to the available bis‐pyrimidyl‐like coordination sphere strongly influences the frontier orbitals, apparent by, for example, luminescence quenching. Thus, the new bridging ligand motif offers electronic properties, which can be adjusted by the nature of the second metal center. Using the heterodinuclear Ru−Rh complex, visible light‐driven reduction of NAD + to NADH was achieved, highlighting the potential of this system for photocatalytic applications. Abstract : A new bridging ligand, namely pyrimidoquinazolinophenanthroline pqp, was successfully synthesized by a chemistry on the complex method using cross coupling and dehydrogenation reactions. The twisted geometry of pqp bridges the gap of already existing bridging ligands. Its photophysics can be significantly influenced by the introduction of a second metal center. Furthermore, light‐induced redox catalysis was explored with a pqp‐based dyad.