Isolation of a planar π-aromatic Bi ring in a cobalt-based inverse-sandwich-type complex.

Monocyclic π-aromatic compounds are ubiquitous throughout almost all fields of natural sciences-as synthons in industrial processes, as ligands of metal complexes for catalysis or sensing and as bioactive molecules. Planar organocycles stand out through their specific way of overcoming electron deficiency by a non-localizable set of (4n + 2)π electrons. By contrast, all-metal aromatic monocycles are still rare, as metal atoms prefer to form clusters with multiply bonded atoms instead.

Unveiling the Werner-Type Cluster Chemistry of Heterometallic 4f/Post-Transition Metals: A {DyBi} Complex Exhibiting Quantum Tunneling Steps in the Hysteresis Loops and its 1-D Congener.

A new [DyBiOCl(saph)] () Werner-type cluster has been prepared, which is the first Dy/Bi polynuclear compound with no metal-metal bond and one of the very few Ln-Bi (Ln = lanthanide) heterometallic complexes reported to date. The molecular compound has been deliberately transformed to its 1-D analogue [DyBiO(N)(saph)] () via the replacement of the terminal Cl ions by end-to-end bridging N groups. The overall metallic skeleton of (and ) can be described as consisting of a diamagnetic {Bi} unit with an elongated trigonal bipyramidal topology, surrounded by a magnetic {Dy} equilateral triangle, which does not contain μ-oxo/hydroxo/alkoxo groups.

Dinuclear Rare-Earth β-Diketiminates with Bridging 3,5-Di-butyl-catecholates: Synthesis, Structure, and Single-Molecule Magnet Properties.

The dinuclear β-diketiminato complex [LClDy(μ-Cl)DyL(THF)] () (L = {2,6-PrCH-NC(Me)CHC(Me)N-2,6-PrCH}) was obtained by reaction of DyCl with KL in a molar ratio of 1:1 and used for the preparation of the mixed-ligand complex [LDy(μ-3,5-Cat)] () by salt metathesis reaction with 3,5-CatK (3,5-Cat -3,5-di--butyl-catecholate). Reactions of 3,5-CatNa with [LLnCl(THF)] (Ln = Dy, Y) ligated with the less bulky ligand L = {2,4,6-MeCH-NC(Me)CHC(Me)N-2,4,6-MeCH} afforded the mixed-ligand THF-containing complexes [LLn(μ-3,5-Cat)(THF)] (Ln = Dy (), Y ()). All new complexes were fully characterized, and the solid-state structures were determined by single-crystal X-ray diffraction.

A Nanosized {Ni } Cluster with a 'Flying Saucer' Topology Exhibiting Slow Relaxation of Magnetisation Phenomena at Both 15 K and 1.3 K.

A high-nuclearity {Ni} complex (1) with a unique 'flying saucer' motif has been prepared from the organic chelate, α-methyl-2-pyridine-methanol (mpmH), in conjunction with bridging azido (N ) and peroxido (O ) ligands. Magnetic susceptibility measurements revealed the presence of both ferro- and antiferromagnetic exchange interactions between the metal centres in 1, and the stabilization of spin states with appreciable S values at two different temperature regimes. The end-on bridging azido and alkoxido groups are in all likelihood the ferromagnetic mediators, while the η:η:μ-bridging peroxides most likely promote the antiparallel alignment of the metals' spin vectors, yielding an overall non-zero spin ground state for the centrosymmetric compound 1.

Modulating quantum tunnelling of magnetization in Dy isotopologue dimers.

Qudits are anticipated to streamline quantum computation by minimizing iterations, lowering error rates, and facilitating error correction. It has been shown that Dy(III)-based molecular systems can act as qudits with expanded Hilbert spaces. Achieving a robust intramolecular interaction, whether exchange or dipolar, is crucial for spanning the Hilbert space of qudits; hence, short Dy(III)⋯Dy(III) distances are required.

Magnetic behaviour of a spin-canted asymmetric lanthanide quinolate trimer.

An asymmetrical dysprosium trimer with a molecular formula of was obtained through a reflux reaction employing as starting material Dy(NO)·HO and 8-quinolinoline as ligand. Magnetic susceptibility investigations show the system to be an SMM, which was corroborated by sub-Kelvin μSQUID studies. Upon cooling, the magnetic susceptibility also exhibits a decrease in the product, which was confirmed to be due to intramolecular antiferromagnetic interactions.

Record Quantum Tunneling Time in an Air-Stable Exchange-Bias Dysprosium Macrocycle.

In recent years, dysprosium macrocycle single-molecule magnets (SMMs) have received increasing attention due to their excellent air/thermal stability, strong magnetic anisotropy, and rigid molecular skeleton. However, they usually display fast zero-field quantum tunneling of the magnetization (QTM) rate, severely hindering their data storage applications. Herein, we report the design, synthesis, and characterization of an air-stable monodecker didysprosium macrocycle integrating strong single-ion anisotropy, near-perfect local crystal field (CF) symmetry, and efficient exchange bias.

Phase transitions associated with magnetic-field induced topological orbital momenta in a non-collinear antiferromagnet.

Resistivity measurements are widely exploited to uncover electronic excitations and phase transitions in metallic solids. While single crystals are preferably studied to explore crystalline anisotropies, these usually cancel out in polycrystalline materials. Here we show that in polycrystalline MnZnGeN with non-collinear antiferromagnetic order, changes in the diagonal and, rather unexpected, off-diagonal components of the resistivity tensor occur at low temperatures indicating subtle transitions between magnetic phases of different symmetry.

Insight into ferromagnetic interactions in Cu-Ln dimers with a compartmental ligand.

In the last two decades, efforts have been devoted to obtaining insight into the magnetic interactions between Cu and Ln utilizing experimental and theoretical means. Experimentally, it has been observed that the exchange coupling () in Cu-Ln systems is often found to be ferromagnetic for ≥4f metal ions. However, exchange interactions at sub-Kelvin temperatures between Cu and the anisotropic/isotropic Ln ions are not often explored.

A nested spin structure and single molecule magnet behaviour in an FeDy heterometallic cyclic coordination cluster.

The 20-nuclearity compound [FeDy(tea)(teaH)(NO)]·8MeCN (where teaH = triethanolamine) was synthesised and characterised through single crystal X-ray diffraction and magnetic measurements. The shape of the magnetic hysteresis in the microSQUID measurements was rationalised using the MAGELLAN program.

Direct determination of high-order transverse ligand field parameters via µSQUID-EPR in a EtN[GdPc] SMM.

The development of quantum technologies requires a thorough understanding of systems possessing quantum effects that can ultimately be manipulated. In the field of molecular magnetism, one of the main challenges is to measure high-order ligand field parameters, which play an essential role in the relaxation properties of SMMs. The development of highly advanced theoretical calculations has allowed the ab-initio determination of such parameters; however, currently, there is a lack of quantitative assessment of how good the ab-initio parameters are.

Thermalization of Nuclear Spins in Lanthanide Molecular Magnets.

Single-molecule magnets (SMMs) distinguish themselves in the field of quantum magnetism through the ability to combine fundamental research with promising applications. The evolution of quantum spintronics in the last decade exemplifies the potential held by molecular-based quantum devices. Notably, the readout and manipulation of the nuclear spin states embedded in a lanthanide-based SMM hybrid device were employed in proof of principle studies of quantum computation at the single-molecule level.

Fe-Gd Ferromagnetic Cyclic Coordination Cluster [FeGd(teaH)(N)(HO)] with Magnetic Anisotropy─Theory and Experiment.

The synthesis, structural, and magnetic characterization of [FeLn(teaH)(N)(HO)] (Ln = Gd and Y) and the previously reported isostructural Dy analogue are discussed. The commonly held belief that both Fe and Gd can be regarded as isotropic ions is shown to be an oversimplification. This conclusion is derived from the magnetic data for the Y analogue in terms of the zero-field splitting seen for Fe and from the fact that the magnetic data for the new Gd analogue can only be fit employing an additional anisotropy term for the Gd ions.

Very Anisotropic 2D Molecular Magnetic Materials Based on Pentagonal Bipyramidal Heptacyanidorhenate(IV).

The first neutral 2D heterometallic assemblies based on orbitally degenerate heptacyanidorhenate(IV) were prepared and structurally characterized. An analysis of the magnetic data for the polycrystalline samples of PhP[{Mn(acacen)}Re(CN)]·Solv () and PPN[{Mn(acacen)}Re(CN)]·Solv () have shown that both materials display slow magnetic relaxation at temperatures below 10 and 21 K for and , respectively. Despite the presence of the same molecular magnetic modules that make up the anionic layers, the studied 2D networks differ significantly in magnetic anisotropy, having a small coercive field (0.

Granular aluminium nanojunction fluxonium qubit.

Mesoscopic Josephson junctions, consisting of overlapping superconducting electrodes separated by a nanometre-thin oxide layer, provide a precious source of nonlinearity for superconducting quantum circuits. Here we show that in a fluxonium qubit, the role of the Josephson junction can also be played by a lithographically defined, self-structured granular aluminium nanojunction: a superconductor-insulator-superconductor Josephson junction obtained in a single-layer, zero-angle evaporation. The measured spectrum of the resulting qubit, which we nickname gralmonium, is indistinguishable from that of a standard fluxonium.

Lanthanide Luminescence Thermometry and Slow Magnetic Relaxation in 3-D Polycyanidometallate-Based Materials.

Two three-dimensional (3-D) polycyanidometallate-based luminescent thermometers with the general formula {LnCo(CN)(4-benpyo)(HO)·7HO} Ln = (Dy(III)(), Eu(III)()), based on the red-emissive diamagnetic linker [Co(CN)] and the bulky pyridine derivative that possesses the N-oxide moiety, 4-benzyloxy-pyridine N-oxide (benpyo), were prepared for the first time. The structure of compound has been determined by single-crystal X-ray crystallography while the purity and structure of have been confirmed by CHN, Fourier transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD) analysis. Magnetic AC susceptibility measurements at zero field show no single-molecule magnet (SMM) behavior indicating fast relaxation operating in .

Luminescence thermometry and field induced slow magnetic relaxation based on a near infrared emissive heterometallic complex.

The 1 : 1 : 1 reaction of YbCl·6HO, K[Co(CN)] and bpyO in HO has provided access to a complex with formula [YbCo(CN)(bpyO)(HO)]·4HO (1) in a very good yield while its structure has been determined by single-crystal X-ray crystallography and characterised based on elemental analyses and IR spectra. Magnetic susceptibility studies showed the complex to be a field induced single molecule magnet, as confirmed by μ-SQUID measurements. CASSCF calculations confirm the existence of a = 7/2 ground state, with rather large transverse components, responsible for the fast relaxation characteristic of compound 1 at zero DC field, which is reduced upon application of DC fields.

High-Performance Luminescence Thermometer with Field-Induced Slow Magnetic Relaxation Based on a Heterometallic Cyanido-Bridged 3d-4f Complex.

The 1:1:1 reaction of DyCl·6HO, K[Co(CN)] and bpyO in HO has provided access to a complex with formula [DyCo(CN)(bpyO)(HO)]·4HO () in a very good yield, while [DyFe(CN)(bpyO) (HO)]·4HO () was also precipitated (also in a high yield) using K[Fe(CN)] instead of K[Co(CN)]. Their structures have been determined by single-crystal X-ray crystallography and characterized based on elemental analyses and IR spectra. Combined direct current (dc) and alternating current (ac) magnetic susceptibility revealed slow magnetic relaxation upon application of a dc field.

High nuclearity structurally - related Mn supertetrahedral T4 aggregates.

The simultaneous employment of 1,3-propanediol and di-2-pyridyl ketone in Mn carboxylate chemistry has provided access to three new, structurally-related [Mn] and [Mn] clusters. They are based on nanosized supertetrahedal T4 Mn/O structural cores and exhibit slow relaxation of magnetization below 3.5 K.

Exchange-Bias Quantum Tunneling of the Magnetization in a Dysprosium Dimer.

Single-molecule magnets (SMMs) have been shown to possess bewildering phenomena leading to their proposal in several futuristic applications ranging from data storage devices to the basic unit of quantum computers. The main characteristic for the proposal of SMMs in such schemes is their inherent and intriguing quantum mechanical properties, which in turn, could be exploited in novel devices with larger capacities, such as for data storage or enhanced properties, such as quantum computers. In the quest of SMMs displaying such intriguing quantum effects, herein, we explore the synthesis, structural, and magnetic characterization of a dimeric dysprosium-based SMM composed of a tetradentate Schiff-base ligand with formula [Dy(HL)(benz)(NO)].

Synthesis, characterization, magnetism and theoretical analysis of hetero-metallic [NiLn] partial di-cubane assemblies.

A family of four isostructural [LnNi(L)(μ-OCH)(μ-PhCO)(PhCO)(CHOH)]·2CHOH [where Ln = Gd (1), Tb (2), Dy (3) and Ho (4)] complexes has been synthesized using Schiff base ligand 2-[{(2-hydroxybenzyl)imino}methyl]-6-methoxyphenol (HL). All the complexes possess a partial di-cubane core structure where the growth of the core is contingent upon the ligand anions and solvent generated μ-OCH groups. DC magnetic analysis revealed dominating ferromagnetic interactions between the metal ions, however, we find no slow relaxation characteristics in the AC susceptibility.