Monometallic Lanthanoid Assembly Showing Ferromagnetism with a Curie Temperature of 11 K

We prepared a three-dimensional monometallic lanthanoid assembly, Na5[Ho(THB4−)2]·7H2O (THB = 1,2,4,5-tetrahydroxybenzene), that exhibits ferromagnetism with a Curie temperature of 11 K. Such a ferromagnetic ordering is due to the effective mediation of the magnetic interaction between Ho3+ ions by the THB4− ligand

Monometallic Lanthanoid Assembly Showing Ferromagnetism with a Curie Temperature of 11 K

We prepared a three-dimensional monometallic lanthanoid assembly, Na5[Ho(THB4−)2]·7H2O (THB = 1,2,4,5-tetrahydroxybenzene), that exhibits ferromagnetism with a Curie temperature of 11 K. Such a ferromagnetic ordering is due to the effective mediation of the magnetic interaction between Ho3+ ions by the THB4− ligand

Vanadium(II) Heptacyanomolybdate(III)-Based Magnet Exhibiting a High Curie Temperature of 110 K

We prepared a vanadium heptacyanomolybdate-based magnet, VII2[MoIII(CN)7]·(pyrimidine)2·4.5H2O (VMo), with a Curie temperature (TC) of 110 K, which is the highest TC value in [MoIII(CN)7]-based magnets. Additionally, MnII2[MoIII(CN)7]·(pyrimidine)2·2H2O (MnMo) of a monoclinic structure (P21/n) with TC = 47 K was prepared to confirm the crystal structure of VMo

A Polyoxometalate–Cyanometalate Multilayered Coordination Network

The reaction of the ε-Keggin polyoxometalate (POM) [PMo₁₂O₃₆(OH)₄{La­(H₂O)₄}₄]⁵⁺ with Fe^II(CN)₆^4– under typical bench conditions at room temperature and ambient pressure has afforded the novel [ε-PMo₁₂O₃₇(OH)₃{La­(H₂O)₅(Fe­(CN)₆)_0.25}₄] network, which exhibits a three-dimensional multilayered structure. The compound has been fully characterized by synchrotron-radiation X-ray crystallography, IR spectroscopy, elemental analysis, and thermogravimetric analysis. This coordination network constitutes the first example of a cyanometalate bonded to a POM unit

Green to Red Luminescence Switchable by Excitation Light in Cyanido-Bridged Tb^III–W^V Ferromagnet

Green to Red Luminescence Switchable by Excitation Light in Cyanido-Bridged TbIII–WV Ferromagne

Vanadium(II) Heptacyanomolybdate(III)-Based Magnet Exhibiting a High Curie Temperature of 110 K

We prepared a vanadium heptacyanomolybdate-based magnet, VII2[MoIII(CN)7]·(pyrimidine)2·4.5H2O (VMo), with a Curie temperature (TC) of 110 K, which is the highest TC value in [MoIII(CN)7]-based magnets. Additionally, MnII2[MoIII(CN)7]·(pyrimidine)2·2H2O (MnMo) of a monoclinic structure (P21/n) with TC = 47 K was prepared to confirm the crystal structure of VMo

High Thermal Durability of Water-Free Copper-Octacyanotungsten-Based Magnets Containing Halogen Bonds

Two-dimensional (2-D) cyano-bridged Cu–W bimetallic assemblies that include halogen-substituted pyridine molecules, [Cu^II(3-iodopyridine)₄][Cu^II(3-iodopyridine)₂]₂[W^V(CN)₈]₂ (<b>1</b>) (triclinic crystal structure, <i>P</i>1̅ space group), [Cu^II(3-bromopyridine)₄][Cu^II(3-bromopyridine)₂]₂[W^V(CN)₈]₂ (<b>2</b>) (triclinic, <i>P</i>1̅), and [Cu^II(3-chloropyridine)₂(H₂O)₂][Cu^II(3-chloropyridine)₂]₂[W^V(CN)₈]₂·4H₂O (<b>3</b>) (monoclinic, <i>P</i>2₁/<i>c</i>), were synthesized. Thermogravimetric measurements demonstrate that <b>1</b> and <b>2</b> have high thermal durability up to ca. 150 °C (423 K) due to the lack of water molecules in the crystal and the stacked Cu–W 2-D layers with halogen bonding between halogen-substituted pyridine and the cyano nitrogen of octacyanotungstate. In contrast, <b>3</b> exhibits weight loss above ca. 50 °C (323 K) as the water molecules between the 2-D layers are removed upon heating. Magnetic measurements show that <b>1</b>–<b>3</b> are ferromagnets due to parallel ordering of the magnetic spins on Cu^II (<i>S</i> = 1/2) and W^V (<i>S</i> = 1/2) with Curie temperatures (<i>T</i>_C) of 4.7 K (<b>1</b>), 5.2 K (<b>2</b>), and 7.2 K (<b>3</b>)

Green to Red Luminescence Switchable by Excitation Light in Cyanido-Bridged Tb^III–W^V Ferromagnet

Green to Red Luminescence Switchable by Excitation Light in Cyanido-Bridged Tb^III–W^V Ferromagne

Size-Controlled Synthesis of Polymer Nanoparticles with Tandem Acoustic Emulsification Followed by Soap-Free Emulsion Polymerization

We have developed a novel synthesis method for size-controlled polymer nanoparticles using soap-free emulsion polymerization. This new synthetic method involves sequential ultrasonic irradiation (20 kHz → 500 kHz → 1.6 MHz → 2.4 MHz) for acoustic emulsification of a water-insoluble monomer such as methylmethacrylate (MMA) in an aqueous medium, followed by emulsion polymerization in the obtained solution without using any surfactants. The sequential ultrasonication (tandem acoustic emulsification) could provide a clear and stable emulsified solution containing monomer droplets with relatively narrow size distribution in the nanometer range. The subsequent polymerization in this solution yielded size-controlled polymer nanoparticles. Furthermore, colloidal crystal films could be easily prepared from the as-polymerized nanoparticle solution using the fluidic-cell method

Chiral Ln^III(tetramethylurea)–[W^V(CN)₈] Coordination Chains Showing Slow Magnetic Relaxation

We prepared a series of isostructural chiral cyanido-bridged zigzag chains [Ln­(tmu)₅]­[W­(CN)₈] (Ln = Gd, <b>1</b>; Tb, <b>2</b>; Dy, <b>3</b>; Ho, <b>4</b>; Er, <b>5</b>; Tm, <b>6</b>) using achiral tmu = tetramethylurea. Their chiral character was confirmed with single crystal X-ray diffraction and circular dichroism measurements. Magnetic studies show antiferromagnetic interactions within cyanido-bridged Ln^III–W^V pairs, and interchain ordering of net spins in <b>1</b>, <b>4</b>, and <b>5</b>. It is worth to emphasize that Dy-, Er-, and Tm-based systems combine magnetic field-induced slow magnetic relaxation and chirality. Analysis of AC magnetic data with two relaxation processes for <b>5</b> gives energy barrier Δ_τ/<i>k</i>_B = 1.2(3) K and relaxation time τ₀ = 2.63(8) × 10^–2 s, and Δ_τ/<i>k</i>_B = 22(2) K and τ₀ = 1.21(3) × 10^–8 s. Cole–Cole function fits for <b>3</b> and <b>6</b> result in Δ_τ/<i>k</i>_B = 17(1) K, τ₀ = 1.68(3) × 10^–6 s and Δ_τ/<i>k</i>_B = 5.7(3) K, τ₀ = 1.53(4) × 10^–2 s, respectively. Slower relaxation processes have been assigned to dipole–dipole interactions while faster ones to single ion magnet behavior of Ln­(III) ions