S. Gambarelli

Coherent spin dynamics of impurity ${\text{Yb}}^{3+}$ ions in the ${\text{CaWO}}_{4}$ single crystal has been studied using $X$- and $W$-band EPR. Rabi oscillations of the sample magnetization with damping times comparable to their period, driven by pulses of the microwave field with duration up to $5\text{ }\ensuremath{\mu}\text{s}$, were observed. The largest value of the single-qubit figure of merit $(\ensuremath{\sim}6400)$ is obtained for the high-field component in the $^{171}\text{Y}\text{b}$ $X$-band EPR spectrum. The spin-lattice relaxation time of the ${\text{Yb}}^{3+}$ ions shortens with the increasing resonance frequency while the phase memory time, in contrast, grows noticeably. Variations of the phase memory times are interpreted in terms of spectral and instantaneous diffusions. The increase of the coherence time at the $W$ band can be used for the application of rare-earth ions as qubits in quantum computing as it has been proposed recently.

Abstract The catalytic hydrogen‐isotope exchange (HIE) of unactivated C(sp 3 )─H bonds remains a formidable challenge, relevant for the synthesis of high‐purity high‐value perdeuterated NMR solvents such as pentane or tetrahydrofuran. Existing methods primarily rely on precious metal‐based catalysts (eg. Ir, Ru) under homogeneous conditions. In pursuit of more sustainable alternatives, we report the synthesis of the heterobimetallic complex [Ta(CH 2 t Bu) 2 (μ‐CH t Bu) 2 CoCp*], 1 , which is used for the preparation of a novel silica‐supported tantalum–cobalt heterobimetallic catalyst through Surface OrganoMetallic Chemistry (SOMC). This Ta/Co material demonstrated exceptional catalytic efficiency in perdeuterating pentane under mild conditions (room temperature, < 1 bar D 2 , 1 mol% cat.), outperforming both the Ta monometallic and the noble‐metal based Ta/Ir heterobimetallic analogues. Furthermore, we took profit of the complementary arene HIE and deuterogenation activities of the Ta/M (M = Ir, Co) catalysts to develop a tandem catalytic synthetic strategy for the efficient preparation of perdeuterated tetrahydrofuran from furan, achieving up to 94% total deuterium incorporation. This novel catalytic system offers several key advantages such as a) mild reaction conditions, b) atom‐efficient use of D 2 as the deuterium source, and c) simplified handling, allowing for the recovery of pure deuterated solvent via simple condensation, not hampered by the use of solvents nor additives.

Abstract The catalytic hydrogen‐isotope exchange (HIE) of unactivated C(sp 3 )─H bonds remains a formidable challenge, relevant for the synthesis of high‐purity high‐value perdeuterated NMR solvents such as pentane or tetrahydrofuran. Existing methods primarily rely on precious metal‐based catalysts (eg. Ir, Ru) under homogeneous conditions. In pursuit of more sustainable alternatives, we report the synthesis of the heterobimetallic complex [Ta(CH 2 t Bu) 2 (μ‐CH t Bu) 2 CoCp*], 1 , which is used for the preparation of a novel silica‐supported tantalum–cobalt heterobimetallic catalyst through Surface OrganoMetallic Chemistry (SOMC). This Ta/Co material demonstrated exceptional catalytic efficiency in perdeuterating pentane under mild conditions (room temperature, < 1 bar D 2 , 1 mol% cat.), outperforming both the Ta monometallic and the noble‐metal based Ta/Ir heterobimetallic analogues. Furthermore, we took profit of the complementary arene HIE and deuterogenation activities of the Ta/M (M = Ir, Co) catalysts to develop a tandem catalytic synthetic strategy for the efficient preparation of perdeuterated tetrahydrofuran from furan, achieving up to 94% total deuterium incorporation. This novel catalytic system offers several key advantages such as a) mild reaction conditions, b) atom‐efficient use of D 2 as the deuterium source, and c) simplified handling, allowing for the recovery of pure deuterated solvent via simple condensation, not hampered by the use of solvents nor additives.