Paramagnetic molecules can serve as electron spin qubits for quantum information processing, provided that they preserve their spin coherence for a sufficient time to allow for computation and error correction. Here we report the rare isolation of stable Zr(III) aryloxide complexes, where Zr is an earth-abundant metal ion with a coherently manipulable electron spin. Density functional theory calculations reveal the trigonal planar d1 geometry stabilizes a 4dz2–5s hybrid singly occupied molecular orbital with little ligand contribution and significant s character (25–27%), yielding large isotropic hyperfine coupling constants of 803–809 MHz. We observed long spin–lattice relaxation times (T1) up to 87 ms and dephasing times (Tm, TmCPMG) up to 123 μs using isotope-selective pulsed electron paramagnetic resonance spectroscopy. Nutation experiments further showed coherent manipulation of several electronic and electronuclear transitions. This study introduces Zr(III) aryloxides as competitive molecular qudits and expands the scope of metal ions to more earth-abundant metals. Zr(III) complexes have been historically challenging to isolate owing to their tendency to dimerize or disproportionate. Now, bulky aryloxide ligands have been used to kinetically stabilize mononuclear Zr(III) ions at room temperature. The electronic and electronuclear transitions of these complexes can also be coherently manipulated as competitive molecular qudits.
Temperature is a fundamental parameter in reaction kinetics, typically accelerating rates according to the Arrhenius law. In catalytic systems, however, competing pathways often respond differently to temperature, allowing the selective promotion of desired reactions while suppressing undesired ones through temperature modulation. Here we show that regulating the temperature near the freezing point of water can resolve the activity–stability trade-off in the oxygen evolution reaction on manganese dioxide. Although lowering the temperature decreases water oxidation rates, catalyst degradation through permanganate formation is suppressed more effectively, extending catalyst lifetime. Counterintuitively, further cooling below 0 °C accelerates permanganate formation, yielding an optimum temperature near 0 °C that balances activity and stability. This anti-Arrhenius behaviour, arising from electrolyte supercooling, is a rare example of anomalous temperature-dependent electrocatalysis under subzero conditions. Our findings highlight temperature regulation as a viable strategy for enhancing catalytic lifetime, with implications for electrochemical systems operating in wintertime and in polar and extraterrestrial environments. Temperature can influence competing catalytic pathways differently, but its role in balancing electrocatalytic activity and stability remains underexplored. Now it has been shown that cooling water to near freezing selectively suppresses manganese dioxide dissolution, extending water oxidation lifetime and revealing anomalous subzero kinetics.
Silicon anodes enable high-energy-density Li-ion batteries but face reversibility challenges when operating under extreme temperature and charge-rate conditions. Now, a liquid electrolyte design results in interface protection and reduced electrode expansion during such operation, while also having lithium plating tolerance.
The generation of unidirectional motion has been a long-standing challenge in the engineering of molecular motors and, more generally, machines. A molecular motor is characterized by a set of low-energy states that differ in their configuration, that is, position or rotation. In biology and Feringa-type motors, unidirectional motion is driven by excitation of the molecule into a high-energy transitional state followed by a directional relaxation back to a low-energy state. Directionality is created by a steric hindrance to movement along one of the directions on the path from the excited state back to a low-energy state. Here we showcase a principal mechanism for the generation of unidirectional rotation of a molecule without the need for steric hindrance and transitional excited states. The chemical design of the molecule—consisting of a platform, an upright axle and a chiral rotor moiety—enables a rotation mechanism that relies on the transfer of orbital angular momentum from the driving current to the rotor. The transfer is mediated via orbital currents that are carried by helical orbitals in the axle. Molecular motors typically rotate by cycling through excitation and relaxation to ground states. Now it has been shown that a molecular motor can be driven by angular-momentum transfer. Circulating positive and negative currents flowing through orbitals of opposite helicity along a carbon–carbon triple bond enable unidirectional rotation.
Programming hierarchical helicity from molecular stereochemistry remains a major challenge in synthetic materials. Collagen achieves this through conformational preorganization that translates local stereochemical information into homochiral triple helices, a level of hierarchical control rarely realized in artificial systems. Here we show that atomically precise Au4 nanoclusters encode local stereochemical information into a homochiral triple helix through a collagen-inspired assembly mechanism. A configuration-dependent endo–exo puckering of thiazolidine-2-thione ligands acts as a stereochemical switch, controlling metal-site exposure and biasing Au···Au metallophilic interactions. This intrachain preorganization fixes the torsional geometry of single helices, which then cooperatively braid into left-handed and right-handed triple helices, respectively. Systematic steric modulation redirects the assembly into alternative architectures, demonstrating programmable control over helicity. The triple-helical superstructures exhibit amplified chiroptical responses. These results establish a transferable molecular grammar for hierarchical helicity in metal nanoclusters and identify metallophilicity as a design principle for biomimetic materials. Translating local stereochemical information into higher-order helical architectures is a central challenge in materials design. Now it has been shown that stereochemically preorganized Au4 nanoclusters assemble into homochiral triple helices through directional aurophilic interactions, providing a design strategy for chiral nanocluster materials with amplified chiroptical responses.
