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Based on a multidentate Schiff-base ligand, N,N′-bis(2-hydroxy-5-methyl-3-formylbenzyl)-N,N′-bis-(pyridin-2-ylmethyl)ethylenediamine (H2L), two binuclear DyIII compounds, with formulas [Dy2(L)(NO3)3(CH3O)] (1) and [Dy2(L)(NO3)3(CH3CH2O)] (2), have been synthesized under different solvent systems. The DyIII ions in 1 and 2 adopt monocapped square antiprism coordination geometries, while different structural distortions can be observed. The two DyIII ions in 1 and 2 are bridged by two phenoxide atoms of one L2− ligand and one bridged CH3O−/CH3CH2O− oxygen node, leading to an approximate fusiform Dy2O3 core. The different DyIII–Obridged node distances, DyIII–Obridged node–DyIII angles and DyIII⋯DyIII distances can be observed. Magnetic studies reveal that 1 and 2 display slow magnetic relaxation behaviours under a zero direct-current field with the effective energy barriers (Ueff) of 114.17 K and 171.23 K, respectively. Furthermore, compound 2 possesses the highest Ueff in nine-coordinated Dy2 compounds. The M versus H data exhibit weak butterfly-shaped hysteresis loops at 2 K for 2. The rare CH3O−/CH3CH2O−-bridged nine-coordinated binuclear DyIII single-molecule magnets (SMMs) significantly regulate and enhance the Ueff of compounds 1 and 2. To deeply understand their different magnetic behaviours, the magnetic anisotropies and magnetic interactions of 1 and 2 were studied by ab initio calculations. These findings demonstrate an efficient approach for regulating and enhancing the magnetic anisotropy barriers using a bridged CH3O− anion or CH3CH2O− anion. [ABSTRACT FROM AUTHOR]

Six phosphomolybdate compounds based on the sandwich-type cluster [M(P4Mo6X31)2] (M = Na, Mn, Na/Cu; X = O or OH) have been solvothermally synthesized by using various organic/inorganic cations as templates, namely, (H3AEP)4[Na(P4Mo6O31H5.5)2]·4H2O (1), (Me2NH2)7[NaMn(H2O)][Mn(P4Mo6O31H6)2]·5H2O (2), (H4tpc)0.5(H4tpb)0.5(H0.5bpp)[Na2.5(H2O)][Na(P4Mo6O31H8)2]·2H2O (3), (Me2NH2)6.5[Na4(H2O)8][Cu0.25Na0.75(P4Mo6O31H6.25)2] (4), (Me2NH2)1.5(NH4)4[Mn1.5Na4.5(H2O)7][Mn(P4Mo6O31H4.5)2]·3.5H2O (5), and (DMIm)4[Mn1.5Na2(H2O)8][Mn(P4Mo6O31H6.5)2]·1.5H2O (6) (AEP = 1-(2-aminoethyl) piperazine, Me2NH = dimethylamine, bpp = 1,3-bis(4-pyridyl)propane, tpb = 1,2,4,5-tetra(4-pyridyl)-benzene, tpc = a,a-1,4-dihydroxy-e,e,e,e-1,2,4,5-tetra-(4-pyridyl)cyclohexane, and [DMIm] = 1,3-dimethylimidazolium). These compounds were characterized by elemental analysis, PXRD, IR, TGA, and single-crystal X-ray diffraction. Compound 1 features a classical zero-dimensional (0D) dimeric cluster [Na(P4Mo6O31H5.5)2]. Compound 2 possesses a 1-D chain constructed from the linkage of [Mn(P4Mo6O31H6)2] dimeric clusters and M (M = Na+, Mn2+) linking metal ions. Compounds 3 and 4 are characteristic of 2-D layers, which are built up by connecting [Na(Mo6P4O31H8)2] and [M(Mo6P4O31H6.5)2] (M = Cu0.25/Na0.75) dimeric clusters, respectively, via Na+ ions. Compounds 5 and 6 feature 3D frameworks, where the dimeric clusters are interconnected by M (M = Na+, Mn2+) ions. Thus, the application of linking metal ions with different coordination modes and valence states to assemble [M(P4Mo6X31)2] clusters is promising for harvesting new phosphomolybdates. In particular, compounds 1 and 5 exhibited visible light degradation performance for Rhodamine B. [ABSTRACT FROM AUTHOR]

The hydrothermal synthesis of VO2 (M) nanoparticles is commonly considered as a result of the transformation of intermediate phase VO2 (A) or VO2 (B). Here, we found a new intermediate phase (NH4)2V4O9 that appeared in the hydrothermal synthesis and played a crucial role in the formation of VO2 (M) nanoparticles. Then, the mechanism for the transformation of intermediate (NH4)2V4O9 to VO2 (M) was described as a self-assembly–decomposition–nucleation–growth process. Pure crystalline VO2 nanoparticles were ultimately obtained and showed excellent thermochromic properties. The phase-transition temperature Tc of VO2 (M) nanoparticles is approximately 65 °C. Furthermore, VO2 flexible foils on PET at a VO2 solid content of 1.5–2.0% show excellent optical properties with luminous transmittance (Tlum) ＞ 50% and solar energy modulation ability (ΔTsol) ＞ 15%. [ABSTRACT FROM AUTHOR]