A family of mono-nuclear lanthanide-radical complexes: Synthesis, structures, magnetic and fluorescent properties

[Display omitted] •Two Ln-radical complexes were successfully synthesized and structurally characterized.•The Tb complex displays SMM behavior and strong characteristic emissions. Two new rare earth complexes based on TEMPO derivative namely [Ln(hfac)3(H2O)hmb-TEMPO] (Ln = Gd 1, Tb 2; hmb-TEMPO = 4-((2-hydroxy-3-methoxybenzylidene) amino)-2,2,6,6-tetramethyl; hfac = hexafluoroacety lacetonate) were successfully synthesized through reacting hmb-TEMPO radical and Ln(hfac)3. Single-crystal X-ray diffraction reveals that 1 and 2 are isostructural complexes in which the LnIII ion is surrounded nine oxygen atoms and displayed distorted tricapped trigonal prism geometry. Magnetic studies show that antiferromagnetic interactions dominate in complex 1. Nonzero out-of-phase signals were observed for complex 2, indicating single-molecule magnet behavior. The low-temperature photoluminescence spectrum of complex 2 were investigated and discussed in detail.