Syntheses, structures and magnetic properties of the lanthanide complexes of the pyrimidyl-substituted nitronyl nitroxide radical.

Four 2p-4f Ln-radical complexes, [(NIT-2-Pm)Ln(hfac)]·0.5CH (NIT-2-Pm = 2-pyrimidyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxy-3-oxide, hfac = hexafluoroacetylacetonato, Ln = Tb (1), Dy (2), Ho (3) and Er (4)), and four 4f-2p-4f Ln-radical-Ln complexes, [(μ-NIT-2-Pm)Ln(hfac)(HO)]·0.5CH (Ln = Tb (5), Dy (6), Ho (7) and Er (8)) have been synthesized and characterized structurally and magnetically.

Slow Magnetic Relaxation in One-Dimensional Azido-Bridged Co Complexes.

Crystal structures and magnetic properties of three one-dimensional (1D) azido-bridged cobalt(II) chains with different amide ligands (L), [Co(N)(DMF)] (1), [Co(N)(DEF)] (2), and [Co(N)(DIPF)] (3) (DMF = N,N-dimethylformamide, DEF = N,N-diethylformamide, and DIPF = N,N-diisopropylformamide), are reported to investigate the influence of L on their structures and magnetic properties. Single-crystal X-ray crystallographic analysis revealed that, although 1-3 all consist of cobalt chains bridged by end-on (EO) azides, the coordination geometry of the Co ions and the repeating units of the 1D structures are quite different. As the size of L increases, the ratio of L to Co decreases from 6:4 in 1 to 5:4 and 4:4 in 2 and 3, respectively.

Three-Dimensional Fe-[Mo(CN)] Magnets with Ordering below 65 K and Distinct Topologies Induced by Cation Identity.

Two cyanide-bridged compounds based on the Fe cation and the anisotropic [Mo(CN)] anion, namely, {Fe(HO)[Mo(CN)]·5HO} (1) and {[NH(CH)]Fe(HO)[Mo(CN)]·8HO} (2), have been prepared. Single crystal X-ray analyses revealed that their structures exhibit different three-dimensional topologies as a result of the addition of [NH(CH)] during the synthesis of 2. For both 1 and 2, the geometry of the [Mo(CN)] unit is a slightly distorted capped trigonal prism; all Fe centers are hexacoordinate and adopt a distorted octahedral configuration.