Manipulation of the charge and spin state of metal atoms and clusters inside fullerenes

• Applicants: Professor Dr. Martin Knupfer; Dr. Alexey A. Popov
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Inorganic Molecular Chemistry - Synthesis and Characterisation ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396256051

• Final Report Year: 2022

Final Report Abstract

This collaborative project was aimed at the better understanding of electron transfer processes of endohedral metallofullerenes (EMFs) in solution and in solid state and the influence of the electron transfer on electronic and magnetic properties. We synthesized a series of EMFs with the focus on those molecules, which can exhibit endohedral electron transfer, i.e. the molecules in which the valence and spin state of endohedral metals can be changed in redox processes. A particular important family of EMFs in the context of this project were the dimetallofullerenes with metal-metal bonding orbital. We demonstrated that the population of the metal-metal bonding orbital can be changed in redox processes, either electrochemically or with chemical redox reagent. The M-M bonding orbital and its electron population have a crucial influence on the magnetic interactions between lanthanide ions, which could be demonstrated by various magnetic and spectroscopic techniques. These finding encouraged further studies of electronic properties of EMFs in thin films and charge transfer interfaces. The showcase study of the EMF Ce@C82 in an interface with the strong electron acceptor F6TCNNQ using valence and core electron spectroscopies demonstrated the reduction of F6TCNNQ, the oxidation of the fullerene cage and preservation of the Ce valence state in the interface.

Publications

• Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal–metal bond. Nature Communications, 10(1).
  Liu, Fupin; Velkos, Georgios; Krylov, Denis S.; Spree, Lukas; Zalibera, Michal; Ray, Rajyavardhan; Samoylova, Nataliya A.; Chen, Chia-Hsiang; Rosenkranz, Marco; Schiemenz, Sandra; Ziegs, Frank; Nenkov, Konstantin; Kostanyan, Aram; Greber, Thomas; Wolter, Anja U. B.; Richter, Manuel; Büchner, Bernd; Avdoshenko, Stanislav M. & Popov, Alexey A.
  
• An unusual donor–acceptor system MnIIPc-TCNQ/F4-TCNQ and the properties of the mixed single crystals of metal phthalocyanines with organic acceptor molecules. Dalton Transactions, 48(46), 17252-17257.
  Kataeva, Olga; Metlushka, Kirill; Ivshin, Kamil; Nikitina, Kristina; Alfonsov, Vladimir; Vandyukov, Alexander; Khrizanforov, Mikhail; Budnikova, Yulia; Sinyashin, Oleg; Krupskaya, Yulia; Kataev, Vladislav; Büchner, Bernd & Knupfer, Martin
  
• Single-Electron Lanthanide-Lanthanide Bonds Inside Fullerenes toward Robust Redox-Active Molecular Magnets. Accounts of Chemical Research, 52(10), 2981-2993.
  Liu, Fupin; Spree, Lukas; Krylov, Denis S.; Velkos, Georgios; Avdoshenko, Stanislav M. & Popov, Alexey A.
  
• Charge transfer characteristics of F 6 TCNNQ–gold interface. Surface and Interface Analysis, 52(12), 953-956.
  Kuhrt, Robert; Hantusch, Martin; Knupfer, Martin & Büchner, Bernd
  
• Photoelectron Spectroscopy on Polycyclic Hydrocarbon–F6TCNNQ Interfaces. The Journal of Physical Chemistry C, 124(5), 2961-2967.
  Hantusch, Martin; Kuhrt, Robert & Knupfer, Martin
  
• Synthesis and charge transfer characteristics of a ruthenium–acetylide complex. RSC Advances, 10(70), 43242-43247.
  Kuhrt, Robert; Ho, Po-Yuen; Hantusch, Martin; Lissel, Franziska; Blacque, Olivier; Knupfer, Martin & Büchner, Bernd
  
• New Charge Transfer Cocrystals of F2TCNQ with Polycyclic Aromatic Hydrocarbons: Acceptor–Acceptor Interactions and Their Contribution to Supramolecular Arrangement and Charge Transfer. Crystal Growth & Design, 22(1), 751-762.
  Kataeva, Olga; Ivshin, Kamil; Metlushka, Kirill; Nikitina, Kristina; Khrizanforova, Vera; Budnikova, Yulia; Fayzullin, Robert R.; Latypov, Shamil; Schiemenz, Sandra; Bretschneider, Michael; Popov, Alexey; Avdoshenko, Stanislav; Krupskaya, Yulia; Büchner, Bernd & Knupfer, Martin
  
• Photoemission Study of Charge Transfer between ET (BEDT-TTF) and Acceptors F6TCNNQ and F2TCNQ. The Journal of Physical Chemistry C, 125(34), 18961-18967.
  Kuhrt, Robert; Hantusch, Martin; Buechner, Bernd & Knupfer, Martin
  
• Strong Photophysical Diversity and the Role of Charge Transfer Excitons in Transition Metal Phthalocyanine β-Phases. The Journal of Physical Chemistry C, 125(22), 12398-12404.
  Doctor, Louis P.; Naumann, Marco; Ziegs, Frank; Büchner, Bernd; Popov, Alexey & Knupfer, Martin
  
• Charge transfer in organic semiconductor systems probed by photoemission spectroscopy, PhD Thesis, TU Dresden, 2022
  R. Kuhrt