Dinuclear Coordination Compounds Based on a 5‑Nitropicolinic Carboxylate Ligand with Single-Molecule Magnet Behavior

Isostructural dinuclear dysprosium and yttrium coordination compounds based on the 5-nitropicolinic carboxylate ligand were synthesized and characterized. The formation of these air-stable complexes is achieved via solvothermal routes employing water as the reaction solvent. The dysprosium-based complex exhibits single-molecule magnet behavior with frequency dependence of the out-of-phase susceptibility at zero direct-current field. High-resolution mass spectrometry (electrospray ionization) experiments and advanced NMR methods including diffusion NMR techniques were applied on the diamagnetic yttrium analogue and established that these species retained their solid-state structure in solution with hydrodynamic radii of 6.5 Å. Full ¹H, ¹³C, ¹⁵N, ⁸⁹Y, Δ¹H_coord, Δ¹³C_coord, and Δ¹⁵N_coord NMR data are given, and through the analysis of the Ramsey equation, the first electronic insights of these derivatives are provided.