Front Cover: Complexes of d- and f-metal Ions with a Redox-Active and Highly Symmetric Truxenone Ligand: Effect of Cations and Coordination on Distortions of Radical Anions and Singlet-Triplet Transitions in Dianions (Eur. J. Inorg. Chem. 14/2025)

Abstract

The Front Cover shows truxenone (Tr), which has high C_3h symmetry and degenerated LUMO. It forms salts and complexes. Calculations predict Jahn–Teller distortions for Tr^⋅− that are enhanced by the asymmetric approach of Cp*₂Co⁺ to Tr^⋅−. The dianions should have a triplet state, but the asymmetric approach of Cs⁺ to the oxygen atoms of Tr²⁻ stabilizes the singlet ground state. Radical anions of Tr^⋅− coordinate with Tb^III(TMHD)₃ and Mn^II(acac)₂ providing asymmetric spin density localization on the coordinated oxygen atom and strong magnetic exchange of the ligand and paramagnetic metal spins. More information can be found in the Research Article by D. V. Konarev and co-workers (DOI: 10.1002/ejic.202400760).