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Abstract: On the basis of the experimentally synthesized [(PY5Me2)4Mn4Re(CN)7]5+, the theoretically modeled clusters of [(PY5Me2)4V4Re(CN)7]5+ and [(PY5Me2)4Ni4Re(CN)7]5+ both have strong magnetic anisotropy energy barriers. [Copyright &y& Elsevier]

Graphical abstract The static and dynamic magnetic properties of two seven-coordinate Co(II)–nitrate complexes adopting the distorted pentagonal bipyramid geometry have been studied. Their easy-plane magnetic anisotropies have been revealed by static magnetic data and theoretical calculations. They display slow magnetic relaxation under a 0.1 T applied dc field. Abstract Two seven-coordinate cobalt(II) complexes with the molecular formulae [Co(L)(NO 3) 2 (CH 3 CN)] (L = 2,2′-bipyridine, 1 ; L = 1,10-phenanthroline, 2) were prepared and magnetically characterized. X-ray single crystal diffraction shows that 1 exhibit the distorted pentagonal bipyramidal geometry around the central Co(II) ion, similar to 2. Magnetic anisotropies and single-molecule magnet behaviors of 1 and 2 have been studied by direct and alternating current magnetic measurements. The static magnetic data show the easy-plane magnetic anisotropies with positive zero-field splitting D value of 32.9(2) cm−1 for 1 and 31.4(2) cm−1 for 2 , which are confirmed by theoretical calculations by CASPT2 and DDCI3 methods. Both 1 and 2 display the field-induced slow magnetic relaxation under 0.1 T applied dc field. [ABSTRACT FROM AUTHOR]

• Two mononuclear Dy complexes based on the luminescent chromophore coumarin ligand have been synthesized and structurally characterized. • Both Dy(III) complexes exhibited a magnetic relaxation phenomenon attributable to their large magnetic anisotropy. • Both two Dy(III) complexes displayed the distinctive emission spectra. Lanthanide luminescent single-molecule magnets (SMMs) serve as a kind of multifunctional molecular materials that have attracted extensive attention. Herein, a novel chromophore coumarin ligand 7-(diethylamino)-(2‑hydroxy-3-methoxybenzylidene)-2-oxo-2-chromene-3-carbohydrazide (Hvalcoumarin) is designed to construct the luminescent Dy(III) complexes. Two Dy complexes 1 ([D y (valcoumarin)(DMF) 2 C l 2 ]·(CHCl 3)) and 2 [Dy(valcoumarin)(DMF) 2 (NO 3) 2 ] were synthesized based on the luminescent chromophore coumarin ligand (Hvalcoumarin). X-ray crystallography reveals that the Dy(III) center in complex 1 adopts a hepta-coordinated arrangement by a distorted pentagonal bipyramidal geometry. In contrast, complex 2 exhibits a nine-coordinate arrangement by a spherical capped square antiprism geometry. Magnetic investigations reveal that 1 and 2 exhibit a slow magnetic relaxation phenomenon. Furthermore, the luminescent spectra of 1 and 2 display the characteristic emission profiles associated with Dy(III) spectra. Moreover, theoretical calculations also demonstrated the relaxation dynamics of 1 and 2. The results furnish a potent avenue for the acquisition of multifunctional molecular materials with magnetic and luminescent properties. [Display omitted] Two Dy(III) complexes based on a novel coumarin ligand have been reported, and both of them exhibited slow magnetic relaxation behavior and luminescent properties. [ABSTRACT FROM AUTHOR]

Abstract: A novel magnetic coupling is observed in a unpublished crystal that consists of a mono-nuclear manganese(II) complex, namely, [Mn(DPP)(NCS)2] (DPP=2-(3,5-dimethyl-1H-pyrazol-1-yl)-1,10-phenanthroline), in which neutral DPP molecule functions as tridentate chelated ligand. In the complex Mn(II) ion assumes a distorted trigonal bipyramidal geometry and in the crystal there is a π–π stacking interaction between the adjacent complexes, which involves pyridyl ring and the symmetry-related pyrazolyl ring and pyridyl ring. The fitting for the data of the variable-temperature magnetic susceptibilities with infinite uniform Mn(II) chain formula gave the magnetic coupling constant J =−0.11cm−1, and theoretical calculations reveal that there exists a very weak anti-ferromagnetic coupling between the adjacent Mn(II) ions with J =−0.02cm−1. The magnetic coupling sign is explained based on McConnell I spin-polarization mechanism with the analysis of the spin density population and the factors that dominate the magnetic coupling magnitude. [Copyright &y& Elsevier]

Three mononuclear rare earth complexes constructed by the Schiff base which binds to the RE(III) center in a monodentate coordination mode have been synthesized, magnetically and theoretically investigated. • Three new mononuclear rare earth complexes were successfully synthesized. • HL ligands are coordinated to RE(III) ion in a monodentate coordination mode. • Magnetic properties of 2 and the diluted sample 4 were characterized. • Magnetic axial anisotropy of 2 and 3 were analyzed by using ab initio calculations. Three new mononuclear rare earth (RE) complexes [RE(HL) 2 (NO 3) 3 (CH 3 OH)] (HL = 1-[ N -(4-bromophenyl)]aminomethylidene-2(1 H)naphthalenone; RE = Y (1), Dy (2), Er (3)) have been synthesized. The structures of complexes 1 – 3 were determined by single-crystal X-ray diffraction analyses. Each complex contains two HL ligands which bind to the RE(III) ion in a monodentate coordination mode, three NO 3 – and one coordinated methanol ligands, exhibiting a distorted tricapped trigonal prism (D 3 h) configuration. Slow relaxation of the magnetization under 1 kOe can be observed for complex 2. Further ab initio calculations show that the orientation of the ground magnetic easy axis is parallel with the line of O(HL)-O(HL) with the deviation angle being 4.29°. In addition, the ground g z value of complex 2 is 19.6858, which approximates the limit value of 20. However, the g z value of the low-lying ground state of complex 3 deviates severely from the limit value of 18, indicating weak axial anisotropy. Further measurements of ac susceptibilities confirmed the weak magnetic behavior in complex 3. [ABSTRACT FROM AUTHOR]

Abstract A series of dinuclear lanthanide complexes bridged by three pyridine- N -oxide (PyNO) ligands with formula [Dy 2 (hfac) 6 (4-cpyNO) 3 ]·4H 2 O (Dy1), [Gd 2 (hfac) 6 (4-cpyNO) 3 ]·4H 2 O (Gd1), [Dy 2 (hfac) 6 (4-mepyNO) 3 ] (Dy2), [Gd 2 (hfac) 6 (4-mepyNO) 3 ] (Gd2) (hfac− = hexafluoroacetylacetonate, 4-cpyNO = 4-cyanopyridine N -oxide, 4-mepyNO = 4-Methylpyridine N -oxide), and series of dinuclear lanthanide complexes bridged by two PyNO ligands with formula [Dy 2 (hfac) 6 (4-cpyNO) 2 ] (Dy3), [Y 2 (hfac) 6 (4-cpyNO) 2 ] (Y1), [Gd 2 (hfac) 6 (4-cpyNO) 2 ] (Gd3), [Dy 2 (hfac) 6 (4-mepyNO) 2 ] (Dy4), [Y 2 (hfac) 6 (4-mepyNO) 2 ] (Y2), [Gd 2 (hfac) 6 (4-mepyNO) 2 ] (Gd4), were structurally and magnetically characterized. The crystal structures revealed that pyridine- N -oxide serves as an effective bridge to link two Ln(III) centers, and periphery β-diketonate ligands complete the coordination sphere. The number of PyNO bridge can be rationally controlled by the stoichiometric ratio of reagents, which leads to different local coordination models and intramolecular Ln-Ln distances. Furthermore, elaborate modulation on the strength of magnetic coupling transmitted by PyNO bridge was successfully carried out by introducing electron-donating or -withdrawing substituents on the bridge ligand backbone. Magnetic measurements revealed that complex Dy3 displayed significant double zero-field slow magnetic relaxation process, while Dy1 and Dy2 showed field-induced SMM behavior. Significantly enhanced SMMs performance was observed in Dy4 with a hysteresis temperature of 2.5 K. The distinct slow magnetic relaxation behaviors were strongly related to their different individual Dy(III) ion magnetic anisotropy and Dy(III)-Dy(III) coupling, which were further confirmed by ab initio calculation. Graphical abstract The favourable Dy(III)-Dy(III) coupling in combination with the individual coordination symmetry after altering the number of pyridine- N -oxide bridges result in the improvement from field-induced SMMs to the zero-field SMMs. Image 1 Highlights • The field-induced SMMs to the zero-field SMMs transformation can be realized by modulating the number of bridges. • The pyridine-N-oxide serves as an effective bridge to transmit weak magnetic exchange interactions between the Ln(III) ions. • Introduction of electron-donating or withdrawing substituent on the bridges can influence the magnetic relaxation properties. [ABSTRACT FROM AUTHOR]

Two mononuclear sulfur-based dysprosium complexes [(dtc) 3 Dy(bipy)] ( 1Dy , dtc −  = diethyldithiocarbamate anion, bipy = 2,2′-bipyridine) and [(dtc) 3 Dy(dmbipy)]·0.68CH 3 CN ( 2Dy , dmbipy = 4,4′-dimethyl-2,2′-bipyridine) were successfully synthesized and structurally characterized by X-ray diffraction. The Dy III centers of 1Dy and 2Dy are eight-coordinated by six S atoms from three dtc − ligands and two N atoms from bipy ( 1Dy ) or dmbipy ( 2Dy ). Magnetic measurements reveal that the magnetic properties of 2Dy are obviously better than those of 1Dy . Theoretical calculations based on the molecular crystal structures are performed to analyze the difference of the magnetic behavior in two complexes. [ABSTRACT FROM AUTHOR]

The magnetic properties of five DyIII-MII 3d-4f complexes (M = Mn, Fe, Co, Ni and Zn) were studied in detail by comparison due to the same molecule construction. The DyIII-MII assemble (M = Mn, Fe and Ni) behave as field-induced SMMs resulting from the ferromagnetic coupling between DyIII and MII ions, while DyIII-ZnII is SIM and DyIII-CoII does not show the magnetic relaxation. [Display omitted] • In this paper, A series of DyIII-MII 3d-4f complexes (M = Mn, Fe, Co, Ni and Zn) were synthesized. • Their magnetic properties were compared by the magnetostructural correlation. • The coupling between DyIII and MII ions (M = Mn, Fe and Ni) is ferromagnetic. Four Dy-based 3d-4f complexes [MIIDyIII(H 2 L)(NO 3) 3 ](CH 3 OH) 2 (H 4 L = N , N' , N'' , N''' -tetra(2-hydroxy-3-methoxy-5-methylbenzyl)-1,4,7,10-tetraazacyclododecane, M = Mn (2), Fe (3), Co (4) and Ni (5), the solvent of compound 5 is uncertain) were synthesized through the reference method of complex [ZnIILnIII(H 2 L)(NO 3) 3 ](CH 3 OH) 2 (1). The magnetic properties of all the five complexes were measured for comparison. The magnetic results show that all the complexes except 4 behave as single-molecule magnets (SMMs). The magnetostructural analysis and theoretical calculation indicate the ferromagnetic coupling in 2 , 3 and 5 as well as the antiferromagnetic coupling in 4 between DyIII and transition metal ions, while the SMM properties of 1 are caused by the anisotropy of single DyIII ions only. Unexpectedly, neither of the magnetic anisotropic ions in one molecule, namely DyIII and CoII, provides greater advantages for SMM performance. This investigation experimentally proves that the coexistence of magnetic anisotropy of lanthanide ions and ferromagnetic coupling between lanthanide and transition metal ions is important for the design of 3d-4f SMMs. [ABSTRACT FROM AUTHOR]

• Two trinuclear compounds 1 and 2 were synthesized and characterized. • Antiferromagnetic interactions were determined in compound 2. • Complex 1 displays field-induced single-molecule magnet (SMM) behavior. Two trinuclear complexes of formulae [Dy 3 (µ 3- H 2 O)(hmp) 3 (CH 3 COO) 3 ] (1) and [Gd 3 (µ 3 -H 2 O)(hmp) 3 (CH 3 COO) 3 ] (2) were synthesized by employing Dy(CH 3 COO) 3 ·6H 2 O and Gd(CH 3 COO) 3 ·6H 2 O as lanthanide sources and a Schiff-base H 2 hmp (H 2 hmp = 2-(((2-hydroxy-3-methoxybenzyl)imino)methyl)-5-methoxyphenol) as a ligand. Single crystal X-ray diffraction analyses reveal that compounds 1 and 2 are isostructural. The three LnIII ions are bridged by three doubly-deprotonated Schiff-base ligands hmp2−, three acetate ions and one µ 3 -H 2 O molecule, forming a regular triangle structure (Ln...Ln...Ln angles of 60°, and Ln...Ln distances of 3.812 Å for 1 , and 3.838 Å for 2). Magnetic property studies for 1 and 2 indicate that complex 1 displays field-induced single-molecule magnet (SMM) behavior, and there are weak antiferromagnetic interactions among three GdIII ions in complex 2. The main magnetic axes on DyⅢ ions of 1 are calculated by complete-active-space self-consistent field (CASSCF) calculations. Two complexes [Dy 3 (µ 3- H 2 O)(hmp) 3 (CH 3 COO) 3 ] (1) and [Gd 3 (µ 3 -H 2 O)(hmp) 3 (CH 3 COO) 3 ] (2) were synthesized and characterized. Compound 1 displays field-induced single-molecule magnet (SMM) behavior. [Display omitted] [ABSTRACT FROM AUTHOR]

Inserting 3d metal-cmplex Cu(acac) 2 into the crystal lattice of paramagnetic Dy(hfac) 3 (H 2 O) 2 leads to the formation of the first true 3d-4f cocrystal made up of only reactants, which exhibits improved magnetic performance with evident SIM behavior. • A genuine 3d-4f complex cocrystal only composed of reactants. • The cocrystal displays evident SIM behavior. • Co-crystallization is a useful tool for improving the magnetic property of LnIII complex. Employing Cu(acac) 2 to react with Dy(hfac) 3 (H 2 O) 2 (where acac− = acetylacetonate and hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate), the first true 3d-4f metal-complex cocrystal with the composition of [Cu(acac) 2 ·Dy(hfac) 3 (H 2 O) 2 that only consists of reactants, was acquired and structurally characterized. Magnetic investigations revealed that the 4f coformer Dy(hfac) 3 (H 2 O) 2 does not show slow magnetic relaxation behavior even under an applied dc field of 2000 Oe down to 1.9 K, while the obtained 3d-4f cocrystal displays evident slow magnetic relaxation behavior associated with single-ion magnet (SIM) characteristic under the same dc field. This phenomenon is further supported and elucidated by the results of theoretical calculations together with the analyses of their crystal structures. Thus our results first indicate that 3d-4f co-crystallization technique is a useful tool for improving the magnetic performance of lanthanide complexes. [ABSTRACT FROM AUTHOR]

Background Our previous studies have shown that mesencephalic astrocyte-derived neurotrophic factor (MANF) provides a neuroprotective effect against ischemia/reperfusion injury and is also involved in inflammatory disease models. This study investigates the potential role and mechanism of MANF in acute brain damage after traumatic brain injury (TBI). Methods The model of TBI was induced by Feeney free falling methods with male Sprague-Dawley rats. The expression of MANF, 24 hours after TBI, was detected by the immunohistochemistry, immunofluorescence, Western blot, and reverse transcription polymerase chain reaction techniques. After treatment with recombinant human MANF after TBI, assessment was conducted 24 hours later for brain water content, cerebral edema volume in magnetic resonance imaging, neurobehavioral testing, and Evans blue extravasation. Moreover, by the techniques of Western blot and reverse transcription polymerase chain reaction, the expression of inflammatory cytokines (interleukin 1β and tumor necrosis factor α) and P65 was also analyzed to explore the underlying protective mechanism of MANF. Results At 24 hours after TBI, we found that endogenous MANF was widely expressed in the rat's brain tissues and different types of cells. Treatment with a high dose of recombinant human MANF (20 μg/20 μL) significantly increased the modified Garcia score, and reduced brain water content as well as cerebral edema volume on magnetic resonance imaging. Furthermore, MANF alleviated not only the permeability of the blood-brain barrier (BBB) but also the expressions of interleukin 1β and tumor necrosis factor α messenger RNA and protein. Besides, the activation of P65 was also inhibited. Conclusions These results suggest that MANF provides a neuroprotective effect against acute brain injury after TBI, via attenuating blood-brain barrier disruption and intracranial neuroinflammation; the inhibition of the NF-κB signaling pathway might be a potential mechanism. [ABSTRACT FROM AUTHOR]