Claire Wilson

Isomeric carbonyl-bridged TPEs exhibit structure-dependent mechanochromism, enabling reversible low-pressure sensing, invisible ink, and phase-switchable solid-state emission.

Quantum spin liquids (QSLs) are exotic states of matter where geometric frustration and quantum fluctuations suppress conventional magnetic order. S = 1/2 kagome antiferromagnets (KAFMs) are an ideal platform for realizing such behavior, and several mineral-inspired Cu2+-based kagome systems have emerged as promising candidates. Among these, Averievite (Cu5V2O10CsCl) offers a structurally distinct route to frustrated magnetism through its copper oxovanadate framework, which hosts alternating kagome and honeycomb layers. Prior studies have shown that targeted Zn2+ substitution on the honeycomb CuH site can suppress magnetic order and promote QSL-like behavior. Here we investigate Mg2+ substitution in the Averievite family, motivated by the geometric flexibility and favorable scattering contrast of Mg2+ relative to Zn2+, the previously explored diamagnetic dopant. Herein we present the novel MgxCu5–xV2O10CsCl (x = 0, 0.5, 1, 2) family, utilizing X-ray diffraction, single-crystal electron diffraction, and SQUID magnetometry to obtain precise structural parameters, including site occupancies, antisite disorder, and local coordination information, and to correlate these with the varied magnetic behavior. Increasing Mg2+ content leads to a pronounced suppression of both the structural and long-range magnetic ordering, alongside an increased mean field antiferromagnetic interaction, signaling enhanced magnetic frustration. Crucially, electron diffraction data is indicative of less than 1% Mg2+ antisite disorder onto the kagome lattice in the Mg2 compound. This contrasts with Zn-based analogues, preserving the integrity of the S = 1/2 kagome network. At x = 2, neither long-range order nor spin freezing is observed down to 2K, giving a new S = 1/2 KAFM with early hallmarks of QSL behavior and establishing Mg-doped Averievite as a clean and highly tunable platform for exploring QSL ground states.

Lanthanide complexes continue to gain significant interest in molecular quantum science due to their rich electronic structures, which can be engineered to support protected spin states relevant for quantum technologies. Carefully tailored ligand fields can give rise to avoided level crossings between crystal-field perturbed states, which may reduce sensitivity to magnetic field fluctuations. Motivated by this, we investigate an axially compressed pseudo-D6h symmetry air-stable macrocyclic Tb(III) complex [TbIII(LN6)(Ph3SiO)2]+ using ab initio calculations, magnetic and EPR measurements. The axially compressed, pseudo-D6h symmetry imposes a ground state that is predominantly composed of mJ = ±6 for the oblate J = 6 Tb(III) ion, with small admixtures from lower |mJ⟩ components. We investigate the hexagonal vs nonhexagonal transverse crystal field contributions to the tunneling gap, calculating different models by selecting from the ab initio crystal field parameters. Our calculations predict a small tunneling gap, ≈1 GHz, and we test this prediction experimentally using multifrequency EPR on La(III)-diluted powder samples. Our EPR results are consistent with the possibility of a low-energy (several GHz) tunneling gap. The Gd(III) analog [GdIII(LN6)(Ph3SiO)2]+ provides an orbital-quenched comparison, and its magnetic data and EPR spectra are well described using the axial zero-field splitting parameter D, demonstrating experimentally the largely axial ligand field in this pseudo-D6h environment.

Metal–organic frameworks (MOFs) of the type MIL-53(M)-fum, where M3+ cations are connected by fumarate (fum) linkers in the canonical MIL-53 topology, have been investigated as possible adsorbents due to their structural rigidity, high porosity, and biologically endogenous organic linker. Examples reported to date are limited to those comprised of p-block metal ions (e.g., Al3+, Ga3+, and In3+); d-block metal ions (e.g., Fe3+ and Sc3+) tend to form MIL-88A(M) materials with the fumarate linker. Herein, we describe the solvent-induced self-assembly of MIL-53(Sc)-fum, by immersing MIL-88A(Sc) in water or aqueous solutions of N,N-dimethylformamide (DMF). Single-crystal X-ray diffraction confirms the solvent-selective formation of two different conformational isomers of MIL-53(Sc)-fum in this unusual MOF-to-MOF synthesis, and both are found to exhibit structural breathing, in contrast to the predominantly rigid p-block metal homologues. Furthermore, we show that the extent of flexibility can be tuned by postsynthetic cluster anion substitution. Refluxing MIL-53(Sc)-fum samples in methanol results in 40–50% exchange of μ2–OH units for μ2-OCH3 groups, where the steric bulk holds the MOFs in a slightly more open pore configuration, enabling significant N2 adsorption at low pressures in contrast to the fully closed, unfunctionalized precursors. This study provides significant insight into MOF-to-MOF self-assembly, conformational isomerism in MOFs, and the effect of both metal ion and cluster anion substitution on structural flexibility, enabling careful tuning of highly porous MOFs from simple components.

The existence and significant impact of conformational isomerism in the MIL-53-fum family on material properties was demonstrated. Adsorption studies showed improved longevity and refrigeration performance for the uniquely rigid MIL-53(Ga)-fum( c ).

Since the first direct detection of a gravitational wave signal in 2015, advancements in technology have resulted in incremental improvements to the current detector network. Future detectors will exploit new technologies to deliver an order of magnitude improvement in performance by increasing their scale and directly targeting thermal and other noise sources. With many next-generation gravitational wave detectors planning to implement crystalline materials as replacements for fused silica, there is an increasing need for novel techniques in suspension jointing. This work will report on the development and characterisation of a repeatable and repairable laser welding technique for crystalline sapphire. Utilizing a CO 2 laser within a crystal growth machine, specifically designed for laser-heated pedestal growth, we established a reliable method for laser welding sapphire stock pieces of various millimetre scale diameters. Experimental characterisation revealed an upper limit of the weld region to be ≤ 200 μ m , and no measurable detriment to the thermal conductivity or tensile strength due to a welded joint. A thermal conductivity of 4587 Wm − 1 K − 1 at 20 K and a minimum unbroken tensile strength of 1.1 GPa were measured on a welded sample. In addition, cryogenic mechanical loss measurements produced a lowest loss of 3.2 × 10 − 7 at 14 K, allowing a weld loss estimate of 5.1 × 10 − 6 . These initial findings indicate significant potential for sapphire welding as a viable concept in next-generation cryogenic detector suspensions and provide a strong justification for further development of this jointing method.

Silicotungstic acid (H ₄ SiW ₁₂ O ₄₀ ) exhibits reversible redox behaviour exploited in decoupled electrolysis and selective hydrogenation of nitroarenes to anilines, avoiding hydrogen gas and precious metal catalysts.

High performance polyoxometalate–Dy( iii ) SMM hybrid compounds exhibiting photoreduction.

Vibrational analysis of a model cocrystal system: pyrimethanil (an anilinopyrimidine fungicide) and l -tartaric acid (PYL-LTA-CC).