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

摘要

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 angstrom. Full H-1, C-13, N-15, Y-85, Delta H-1(coord), Delta C-13(coord), and Delta N-15(coord) NMR data are given, and through the analysis of the Ramsey equation, the first electronic insights of these derivatives are provided.