Synthesis and characterisation of novel ternary and quaternary transition-metal carbodiimides

• Applicant: Alexander Corkett, Ph.D.
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441856704

• Final Report Year: 2025

Final Report Abstract

The primary goal of this project has been to explore the potential for novel ternary and quaternary transition metal carbodiimides. The [NCN]2− dianion is well thought of as a pseudo-chalcogenide or even divalent nitride and Mx(NCN)y binary phases typically adopt crystal structures similar to those of their oxide and sulphide analogues. However, due to their endothermic nature the synthesis of transition metal carbodiimides presents a significant synthetic challenge. In this project the first examples of non-binary transition metal carbodiimides have been discovered via solid-state metathesis reactions, utilizing the intrinsic energy of the reaction partners to promote an exothermic exchange of the constituent ions under relatively mild conditions. Intriguingly, the majority of the ternary and quaternary phases reported in this project adopt layered crystal structures with a hexagonal close packing of [NCN]2− in [NiAs]-derived structures with metal cations in the octahedral holes. In addition to our structural studies, the physicochemical properties of these novel phases have also been explored. Specifically, we have studied the promising magnetic (MnCr2(NCN)4), non-linear optical (MnHf(NCN)3), photochemical (Na2CoSn2(NCN)6), luminescence (EuZn(NCN)2) and electrochemical (Li2−xMn Sn2(NCN)6) properties of the novel phases synthesized during this project. This 2+x highlights the potential of non-binary transition metal carbodiimides for a range of energy related applications and will undoubtably stimulate further work in this exciting new direction.

Publications

• Synthetic Engineering in Na2MSn2(NCN)6 (M = Mn, Fe, Co, and Ni) Based on Electronic Structure Theory. Inorganic Chemistry, 61(45), 18221-18228.
  Corkett, Alex J.; Chen, Zheng; Ertural, Christina; Slabon, Adam & Dronskowski, Richard
  
• Finding the ‘Goldilocks Zone’: cationic size and tilting of carbodiimide and cyanamide anions. Zeitschrift für Kristallographie - Crystalline Materials, 239(1-2), 17-25.
  Medina-Jurado, Juan; Corkett, Alex J. & Dronskowski, Richard
  
• NiAs-derived cyanamide (carbodiimide) structures – a group-theoretical view. Zeitschrift für Kristallographie - Crystalline Materials, 0(0).
  Pöttgen, Rainer; Corkett, Alex J. & Dronskowski, Richard
  
• On the path to kinetic solid-state chemistry: Activation energy-controlled stepwise synthesis and crystal structure of LiSc(NCN)2. Journal of Solid State Chemistry, 340, 124970.
  Medina-Jurado, Juan; Grysla, Felix; Bourakhouadar, Hicham; Chen, Da; Corkett, Alex J. & Dronskowski, Richard
  
• Perovskite-Like Carbodiimides AB(NCN)3: Synthesis and Characterization of MnHf(NCN)3 and FeHf(NCN)3. Journal of the American Chemical Society, 146(38), 26071-26080.
  Bourakhouadar, Hicham; Hempelmann, Jan; van Leusen, Jan; Drichel, Andreas; Bayarjargal, Lkhamsuren; Koldemir, Aylin; Reimann, Maximilian Kai; Pöttgen, Rainer; Slabon, Adam; Corkett, Alex J. & Dronskowski, Richard
  
• Synthesis, characterization and chemical bonding analysis of the quaternary cyanamides Li2MnHf2(NCN)6 and Li2MnZr2(NCN)6. Dalton Transactions, 53(48), 19272-19279.
  Bourakhouadar, Hicham; Medina-Jurado, Juan; Müller, Peter C.; Corkett, Alex J. & Dronskowski, Richard
  
• The [NCN]2– Carbodiimide Complex Anion and Its Compounds–A “Divalent Nitride” Unit for Nitridocarbonates in Materials and Applications. Chemistry of Materials, 36(19), 9107-9125.
  Corkett, Alex J.; Reckeweg, Olaf; Pöttgen, Rainer & Dronskowski, Richard
  
• Verfahren zum Herstellen von Metall-Carbodiimidien DE10 2024 112 474.1
  Corkett, A. J.; Bourakhouadar H. & Dronskowski, R.
  
• The Missing Tb2O2NCN Compound: Synthesis, Characterization, and Luminescent Properties. Zeitschrift für anorganische und allgemeine Chemie, 651(5).
  Medina‐Jurado, Juan; Bourakhouadar, Hicham; Corkett, Alex J.; Enseling, David; Jüstel, Thomas & Dronskowski, Richard
  
• The Mixed Transition-Metal Cyanamide MnCr2(NCN)4. Inorganic Chemistry, 64(6), 2886-2896.
  Corkett, Alex J.; Okhrymenko, Marharyta; Roddatis, Vladimir; Lebedev, Oleg I.; Leusen, Jan van; Delina, Ruth Esther G.; Perez, Jeffrey Paulo H.; Benning, Liane G. & Dronskowski, Richard