Breaking through the nitrogen ceiling Single-molecule magnets could prove useful in miniaturizing a wide variety of devices. However, their application has been severely hindered by need to cool them extremely low temperature using liquid helium. Guo et al. now report dysprosium compound that manifests magnetic hysteresis at temperatures up 80 kelvin. The principles applied tuning ligands this complex point way toward future architectures with even higher performance. Science , issue p. 1400

Abstraction of a chloride ligand from the dysprosium metallocene [(Cpttt )2 DyCl] (1Dy Cpttt =1,2,4-tri(tert-butyl)cyclopentadienide) by triethylsilylium cation produces first base-free rare-earth metallocenium Dy]+ (2Dy ) as salt non-coordinating [B(C6 F5 )4 ]- anion. Magnetic measurements reveal that [2Dy ][B(C6 ] is an SMM with record anisotropy barrier up to 1277 cm-1 (1837 K) in zero field and magnetic blocking temperature 60 K, including hysteresis coercivity. The exceptional axiality...

Abstract Abstraction of a chloride ligand from the dysprosium metallocene [(Cp ttt ) 2 DyCl] ( 1 Dy Cp =1,2,4‐tri( tert ‐butyl)cyclopentadienide) by triethylsilylium cation produces first base‐free rare‐earth metallocenium Dy] + as salt non‐coordinating [B(C 6 F 5 4 ] − anion. Magnetic measurements reveal that [ ][B(C is an SMM with record anisotropy barrier up to 1277 cm −1 (1837 K) in zero field and magnetic blocking temperature 60 K, including hysteresis coercivity. The exceptional...

The pentagonal bipyramidal single-ion magnets (SIMs) are among the most attractive prototypes of high-performance single-molecule (SMMs). Here, a fluorescence-active phosphine oxide ligand CyPh2 PO (=cyclohexyl(diphenyl)phosphine oxide) was introduced into [Dy(CyPh2 PO)2 (H2 O)5 ]Br3 ⋅2 (CyPh2 PO)⋅EtOH⋅3 H2 O, and combined dynamic magnetic measurement, optical characterization, ab initio calculation, magneto-optical correlation this pseudo-D5h DyIII SIM with large Ueff (508(2) K) high...

Reduction of the uranium(III) metallocene [(η5 -C5 i Pr5 )2 UI] (1) with potassium graphite produces "second-generation" uranocene U] (2), which contains uranium in formal divalent oxidation state. The geometry 2 is that a perfectly linear bis(cyclopentadienyl) sandwich complex, ground-state valence electron configuration uranium(II) revealed by electronic spectroscopy and density functional theory to be 5f3 6d1 . Appreciable covalent contributions metal-ligand bonds were determined from...

Inducing magnetic coupling between 4f elements is an ongoing challenge. To overcome this formidable difficulty, we incorporate highly delocalized tetrazinyl radicals, which strongly couple with f-block metallocenes to form discrete tetranuclear complexes. Synthesis, structure, and properties of two [(Cp*2 Ln)4 (tz. )4 ]⋅3(C6 H6 ) (Cp*=pentamethylcyclopentadienyl; tz=1,2,4,5-tetrazine; Ln=Dy, Gd) complexes are reported. An in-depth examination their through susceptibility measurements as well...

The concept of oxidation state plays a fundamentally important role in defining the chemistry elements. In f block periodic table, well-known states compounds lanthanides include 0, +2, +3 and +4, for actinides range from +7 to +2. Oxidation +1 is conspicuous by its absence f-block Here we show that uranium(II) metallocene [U(η5-C5iPr5)2] uranium(III) [IU(η5-C5iPr5)2] can be reduced potassium graphite presence 2.2.2-cryptand uranium(I) [U(η5-C5iPr5)2]- (1) (C5iPr5 =...

Magnetic bistability in single-molecule magnets (SMMs) is a potential basis for new types of nanoscale information storage material. The standard model thermally activated relaxation the magnetization SMMs based on occurrence single Orbach process. Here, we show that incorporating phosphorus atom into framework dysprosium metallocene [(CpiPr5)Dy(CpPEt4)]+[B(C6F5)4]- (CpiPr5 penta-isopropylcyclopentadienyl, CpPEt4 tetraethylphospholyl) leads to two distinct high-temperature processes, with...

Replacing a monoanionic cyclopentadienyl (Cp) ligand in dysprosium single-molecule magnets (SMMs) with dianionic cyclobutadienyl (Cb) the sandwich complexes [(η

Treatment of toluene solutions the silylenes Si(SAr(Me6))2 (Ar(Me6) = C6H3-2,6(C6H2-2,4,6-Me3)2, 1) or Si(SAr(Pr(i)4))2 (Ar(Pr(i)4) C6H3-2,6(C6H3-2,6-Pr(i)2)2, 2) with excess ethylene gas affords siliranes (Ar(Me6)S)2SiCH2CH2 (3) (Ar(Pr(i)4)S)2SiCH2CH2 (4). Silirane 4 evolves spontaneously at room temperature in solution. A Van't Hoff analysis by variable-temperature (1)H NMR spectroscopy showed that ΔG(assn) -24.9(2.5) kJ mol(-1) for 4. computational study reaction mechanism using a model...

Open AccessCCS ChemistryRESEARCH ARTICLE7 Dec 2022Air-Stable Dy(III)-Macrocycle Enantiomers: From Chiral to Polar Space Group Zhenhua Zhu†, Chen Zhao†, Quan Zhou, Shuting Liu, Xiao-Lei Li, Akseli Mansikkamäki and Jinkui Tang Zhu† State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute Applied Chemistry, Chinese Academy Sciences, 130022 University Beijing 100049 , Zhao† Science Technology China, Hefei 230026 Zhou Liu Li *Corresponding authors: E-mail Address: [email...

Aromatic π-stacking is a weakly attractive, noncovalent interaction often found in biological macromolecules and synthetic supramolecular chemistry. The weak nondirectional nature of can present challenges the design materials owing to their weak, nature. However, when aromatic π-systems contain an unpaired electron, stronger attraction involving face-to-face π-orbital overlap possible, resulting covalent so-called "pancake" bonds. Two-electron, multicenter single pancake bonds are well...

Abstract Single-ion anisotropy is vital for the observation of Single-Molecule Magnet (SMM) properties (i.e., a slow dynamics magnetization) in lanthanide-based systems. In case europium, occurrence this phenomenon has been inhibited by spin and orbital quantum numbers that give way to J = 0 trivalent state half-filled population 4f orbitals divalent state. Herein, optimizing local crystal field quasi-linear bis(silylamido) Eu II complex, [Eu (N{SiMePh 2 } ) ] SMM described, providing an...

Abstract The potassium cyclobutadienyl [K 2 {η 4 ‐C (SiMe 3 ) }] ( 1 reacts with MCl (THF) 3.5 (M=Y, Dy) to give the first rare‐earth complexes, that is, complex anions [M{η }{η ‐κ‐(CH SiMe 2− , M ), as their dipotassium salts. tuck‐in alkyl ligand in is thought form through deprotonation of “squarocene” complexes } ] − by . Complex Dy a single‐molecule magnet, but prominent quantum tunneling. An anisotropy barrier 323(22) cm −1 was determined for an applied field kOe, and magnetic...

Abstract Flexible, chelating bis(NHC) ligand 2 , able to accommodate both cis ‐ and trans ‐coordination modes, was used synthesize ( )Ni(η ‐cod), 3 . In reaction with GeCl it produced )NiGeCl 4 featuring a T‐shaped Ni 0 pyramidal Ge center. Complex could also be prepared from [( )GeCl]Cl, 5 Ni(cod) in that formally involved Ni–Ge transmetalation, followed by coordination of the extruded moiety Ni. A computational analysis showed possesses considerable multiconfigurational character Ni→Ge...

Cycloaddition reactions of the acyclic silylene Si(SAriPr4)2 (AriPr4 = C6H3-2,6(C6H3-2,6-iPr2)2) with a variety alkenes and alkynes were investigated. Its phenylacetylene diphenylacetylene diene 2,3-dimethyl-1,3-butadiene yielded silacycles (AriPr4S)2Si(CH═CPh) (1), (AriPr4S)2Si(PhC═CPh) (2), (AriPr4S)2SiCH2CMeCMeCH2 (3) at ambient temperature. The compounds characterized by X-ray crystallography, 1H, 13C, 29Si NMR spectroscopy, IR spectroscopy. No reaction was observed more substituted such...

A series of d-block metal complexes the recently reported coordinating neutral radical ligand 1-phenyl-3-(pyrid-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl (1) was synthesized. The investigated systems contain benzotriazinyl 1 coordinated to a divalent cation, Mn(II) , Fe(II) Co(II) or Ni(II) with 1,1,1,5,5,5-hexafluoroacetylacetonato (hfac) as auxiliary choice. synthesized were fully characterized by single-crystal X-ray diffraction, magnetic susceptibility measurements, and electronic...

Abstraction of iodide from [(η5 -C5i Pr5 )2 UI] (1) produced the cationic uranium(III) metallocene U]+ (2) as a salt [B(C6 F5 )4 ]- . The structure 2 consists unsymmetrically bonded cyclopentadienyl ligands and bending angle 167.82° at uranium. Analysis bonding in showed that uranium 5f orbitals are strongly split mixed with ligand orbitals, thus leading to non-negligible covalent contributions bonding. Investigation dynamic magnetic properties revealed covalency leads partially quenched...

The dinucleating fulvalenyl ligand [1,1',3,3'-(C5 t Bu2H2)2]2- (Fvtttt) was used to synthesize the dimetallic dysprosocenium cation [{Dy(η5-Cp*)}2(μ-BH4)(η5:η5-Fvtttt)]+ (3) as salt of [B(C6F5)4]- (Cp* = C5Me5). Compound [3][B(C6F5)4] obtained using a method in which double half-sandwich complex [{Dy(BH4)2(THF)}2(Fvtttt)] (1) reacted with KCp* give metallocene [{Dy(Cp*)(μ-BH4)}2(Fvtttt)] (2), followed by removal bridging borohydride upon addition [(Et3Si)2(μ-H)][B(C6F5)4]. complexes 1-3 rise...

Intact transfer of the cyclobutadienyl ligand [C4(SiMe3)4]2- to yttrium and dysprosium (M) produces half-sandwich complexes [M{η4-C4(SiMe3)4}(BH4)2(THF)]- as coordination polymers with bridging sodium or potassium ions. The versions are single-molecule magnets (SMMs) energy barriers 371(7) 357(4) cm-1, respectively. pristine ligands provide a strong axial crystal field that enhances SMM properties relative related cyclopentadienyl compounds.

The combination of the 1,2,4,5-tetrazine (tz) with Ln metallocenes led to a new family radical-bridged dinuclear complexes. Strong magnetic Ln–rad coupling was observed, which afforded zero-field SMM behavior for Tb and Dy analogues.