Three new mononuclear tri-spin lanthanide-nitronyl nitroxide radical compounds: syntheses, structures and magnetic properties.
Based on the nitronyl nitroxide radical, 2-(4-(methoxycarbonyl)phenyl)-4,4,5,5-tetramethylimidazolin-1-oxyl-3-oxide (1, NITPhCOOMe), and three mononuclear tri-spin compounds [Ln(hfac)3(NITPhCOOMe)2] (Ln = Gd (2), Tb (3), Dy (4); hfac = hexafluoroacetylacetonate) are successfully synthesized and fully characterized. Compounds 2 and 4 are isostructural and crystallize in the C2/c space group, while compound 3 crystallizes in the P2₁/c space group. For compounds 2-4, the central metal ions are all eight-coordinate in distorted triangular dodecahedral LnO8 coordination geometry (D(2d) symmetry) completed by three bischelate hfac(-) ligands and two monodentate radicals. Magnetic studies show that radical 1 undertakes the transition from the paramagnetic state to 3D antiferromagnetic ordering at 4.2 K. In addition, compound 3 exhibits field-induced single-molecule magnet (SMM) behavior.
Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, P. R. China. shiwei@nankai.edu.cn.
Lei-Lei
LL
Li
Shuang
S
Liu
Yuan
Y
Zhang
Wei
W
Shi
Peng
P
Cheng