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Asymmetric hydrogenation plays an essential role for both academic research and industry to produce enantiomeric pure chiral molecules. Although nuclear magnetic resonance (NMR) is powerful in determining the yields of hydrogenation, it is still challenging to use NMR for chirality-related analysis. Herein, we applied parahydrogen-induced hyperpolarization (PHIP) NMR to determine the enantioselectivity of asymmetric hydrogenation and the absolute chirality of products. We hyperpolarized two types of unsaturated amino acid precursors, i.e., methyl-α-acetoamido cinnamate and (E)-ethyl 3-acetamidobut-2-enoate. Hydrogenation of prochiral substrates with parahydrogen gave temporary hyperpolarized diastereoisomers, which exhibit different PHIP patterns distinguishable in 1H NMR. After assigning the NMR peaks by density functional theory calculations, we simulated the PHIP patterns of all the possible temporary hyperpolarized diastereoisomers and unambiguously assigned the chirality of the products and the enantioselectivity of asymmetric hydrogenation. Our work demonstrates the application and potential of PHIP in revealing the mechanism of asymmetric hydrogenation. [ABSTRACT FROM AUTHOR]

Abstract: The photoanode plays a critical role in influencing the performance of dye‐sensitized solar cells (DSSCs). In this work, Y0.80Yb0.18Er0.02OF nanorods (YYEOF NRs) are synthetized by a simple hydrothermal method and incorporated into the TiO2 film to form a bi‐layer photoanode consisting of nanoparticles (NPs) on the bottom and nanorods on top. Owing to the improved light collection efficiency and electron transport rate, the resultant YYEOF NRs are advantageous as photoanode dopants for DSSCs. Following assembly into an integrated DSSC, an enhanced photocurrent and power conversion efficiency (PCE) are observed. Benefiting from the p‐type doping effect of the YYEOF NRs, the photovoltage of the DSSCs is elevated. The cell performance can be maximized through optimization of the fraction of YYEOF NRs, and the results demonstrate that a promising PCE of 7.74 % is determined for the DSSC with 5 wt % YYEOF NRs, yielding 32.5 % enhancement in comparison to pristine TiO2 NPs‐based solar cells. This work provides a promising strategy to explore photoanode materials, which will lead to further efficiency improvements for solar cells. [ABSTRACT FROM AUTHOR]

Acting as a passive protective layer, solid-electrolyte interphase (SEI) plays a crucial role in maintaining the stability of the Li-metal anode. Derived from the reductive decomposition of electrolytes (e.g., anion and solvent), the SEI construction presents as an interfacial process accompanied by the dynamic de-solvation process during Li-metal plating. However, typical electrolyte engineering and related SEI modification strategies always ignore the dynamic evolution of electrolyte configuration at the Li/electrolyte interface, which essentially determines the SEI architecture. Herein, by employing advanced electrochemical in situ FT-IR and MRI technologies, we directly visualize the dynamic variations of solvation environments involving Li + -solvent/anion. Remarkably, a weakened Li + -solvent interaction and anion-lean interfacial electrolyte configuration have been synchronously revealed, which is difficult for the fabrication of anion-derived SEI layer. Moreover, as a simple electrochemical regulation strategy, pulse protocol was introduced to effectively restore the interfacial anion concentration, resulting in an enhanced LiF-rich SEI layer and improved Li-metal plating/stripping reversibility., (© 2024 Wiley‐VCH GmbH.)