Three new isostructural binuclear transition metal complexes with azido ion and 1,2-bis(3-(pyridin-2-yl)-lH-pyrazol-1- yl)ethane (bppe), formulated as [M2(N3)2(bppe)2](C104)2 (M = Co, 1; Ni, 2; Cu, 3), were successfully synthesized. They were structurally and magnetically characterized. In 1-3, the double azido ions link two adjacent octahedral metal centers together in the end-to-on mode (EO), with the M-NEo-M angles of 99.41°, 100.24° and 99.80°, respectively. The co-ligand bppe acts as terminal ligand to saturate the remaining coordination sites. The magnetic properties of 1-3 have been investigated in the tem- perature range of 2-300 K. Fitting of the magnetic susceptibility data revealed the occurrence of the strong ferromagnetic in- teractions [J = 26.32 cm-1 (1), J = 38.23 cm-1 (2) and J = 139.83 cm-1 (3)]. Density functional theory calculations have been performed on 1-3 to provide a magneto-structural correlation of the ferromagnetic behavior.
A series of new lanthanide-radical complexes [{Ln(hfac)3}2(NITPhlM)2] (Ln = Nd (1), Eu (2), Tb (3), Er (4); hfac = hexafluoroacetylacetonate; NITPhlM = 2-[4-(1-imidazole)phenyl]-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide) have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln(hfac)3 units bridged by the paramagnetic ligands by the means of coor- dination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl ni- troxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior.
LIU RuiNaHU PengLI LiCunLIAO DaiZhengSUTTER Jean-Pascal
Three new isostructural binuclear transition metal complexes with azido ion and 1,2-bis(3-(pyridin-2-yl)-1H-pyrazol-1-yl)ethane (bppe), formulated as [M2(N3)2(bppe)2](ClO4)2 (M = Co, 1; Ni, 2; Cu, 3), were successfully synthesized. They were structurally and magnetically characterized. In 1-3, the double azido ions link two adjacent octahedral metal centers together in the end-to-on mode (EO), with the M-NEO-M angles of 99.41°, 100.24° and 99.80°, respectively. The co-ligand bppe acts as terminal ligand to saturate the remaining coordination sites. The magnetic properties of 1-3 have been investigated in the temperature range of 2-300 K. Fitting of the magnetic susceptibility data revealed the occurrence of the strong ferromagnetic interactions [J = 26.32 cm-1 (1), J = 38.23 cm-1 (2) and J = 139.83 cm-1 (3)]. Density functional theory calculations have been performed on 1-3 to provide a magneto-structural correlation of the ferromagnetic behavior.