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Salen-type mononuclear lanthanide complexes with formula (Et3NH)[Ln(3-NO2-salen)2]·solvent (Ln = Eu (1Eu), Tb (2Tb), Dy (3Dy), Ho (4Ho), Er (5Er), Yb (6Yb); 3-NO2-salen2− = N,N′-bis(3-nitro-salicylaldehyde)ethylenediamine dianion) are reported. These compounds are isostructural in which two crystallographically distinct 3-NO2-salen2− act as tetradentate ligands encapsulating the lanthanide ions in a meridional mode forming the [LnN4O4] cores. Slow magnetization relaxation processes associated with single ion magnet (SIM) behaviors are observed in complexes 3Dy, 5Er and 6Yb with the Kramer ions but not in 2Tb and 4Ho with non-Kramer ions. Photoluminescence studies reveal that complexes 1Eu, 5Er and 6Yb exhibit characteristic lanthanide luminescence with sharp and well-separated emission bands. Complex 1Eu is of particular interest in which the organic ligand functioning as a powerful absorbing sensitizer apparently broadens the excitation range into 300–500 nm with the maximum of 460 nm. [ABSTRACT FROM AUTHOR]

A pair of enantiopure mononuclear dysprosium/salen-type complexes (Et3NH)[Dy((R,R)/(S,S)-3-NO2salcy)2] (1R/1S), where 3-NO2salcyH2 represents N,N′-(1,2-cyclohexanediylethylene)bis(3-nitrosalicylideneiminato), are reported. The enantiomer contains two crystallographically independent dysprosium(iii) ions, each chelated by two enantiopure 3-NO2salcy2− ligands forming a [DyN4O4] core. Detailed magnetic studies on compound 1R reveal a field-induced dual magnetic relaxation behavior, originating from single ion anisotropy and intermolecular interactions, respectively. [ABSTRACT FROM AUTHOR]

Two purely inorganic three-dimensional (3D) frameworks [Mn4(H2O)11VIV18O42(PO4)]7− (1) and [Mn2(H2O)7VIV18O42(PO4)]11− (2) were synthesized under hydrothermal conditions and fully characterized by single-crystal X-ray structural analysis, IR spectroscopy, thermogravimetric analysis and PXRD. Structural analysis revealed that these two compounds contained a similar all reduced polyoxoanion [VIV18O42(PO4)]15− linked by different amounts of manganese centers to form 3D framework materials. The V centers in these two compounds were all reduced to the +IV oxidation state, resulting in an all reduced polyoxoanion, which was firstly used as the building block for constructing 3D framework materials. The all reduced typical polyoxoanion [VIV18O42(PO4)]15− with 15 negative charges supplied enough charge amount to accept TM cations. In these two structures, the anions were surrounded by 12 and 5 Mn2+ ions, respectively, adjusted by varying the feeding amount of MnCl2·4H2O. An electrocatalytic study revealed that compound 1 exhibits electrocatalytic activity for reduction of H2O2. [ABSTRACT FROM AUTHOR]

Three new chain compounds in which the Mn2(salen)2 dimers are bridged by O–P–O units are reported, namely, [Mn2(salen)2(C6H9PO3H)](ClO4) (1), [Mn2(salen)2(C6H5PO3H)](ClO4) (2) and [Mn2(salen)2(C6H5PHO2)](ClO4) (3). The phosphonate or phosphinate ligands adopt a syn–anti bidentate bridging mode in 1, while a syn–syn bidentate bridging mode in 2 and 3, thus leading to a difference in the Mn–O…O–Mn torsion angle over the O–P–O bridge. Compound 1 shows a paramagnetic behavior with dominant antiferromagnetic interactions. In compounds 2 and 3, the antiferromagnetic interactions through the O–P–O bridges are considerably stronger than those in 1. They display coexistence of single chain magnet (SCM) behaviour with a spin canted structure and metamagnetism at low temperature. The results demonstrate that the magnetic dynamics of the O–P–O bridged Mn2(salen)2 chains may be modulated by selecting suitable phosphonate or phosphinate ligands. [ABSTRACT FROM AUTHOR]