Trapping of a Highly Bent and Reduced Form of 2‐Phosphaethynolate in a Mixed‐Valence Diuranium–Triamidoamine Complex

The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(Tren^TIPS)(OCP)] (Tren^TIPS=N(CH₂CH₂NSiPrⁱ₃)₃) with KC₈/2,2,2‐cryptand gives [{U(Tren^TIPS)}₂{μ‐η²(OP):η²(CP)‐OCP}][K(2,2,2‐cryptand)]. The coordination mode of this trapped 2‐phosphaethynolate is unique, and derives from an unprecedented highly reduced and highly bent form of this ligand with the most acute P‐C‐O angle in any complex to date (P‐C‐O ? ≈127°). The characterisation data support a mixed‐valence diuranium(III/IV) formulation, where backbonding from uranium gives a highly reduced form of the P‐C‐O unit that is perhaps best described as a uranium‐stabilised OCP^2?. radical dianion. Quantum chemical calculations reveal that this gives unprecedented carbene character to the P‐C‐O unit, which engages in a weak donor–acceptor interaction with one of the uranium ions.     

Monoalkyl and monoanilide yttrium complexes containing tridentate pyridyl-1-azaallyl dianionic ligands

A series of pyridyl-1-azaallyl ligand precursors (HL1-HL5) were synthesized via condensation of pyridine ketones with anilines. The alkane elimination reactions between Y(CH(2)SiMe(3))(3)(THF)(2) and HL4 or HL5 gave the monoalkyl complexes (L4-H)YCH(2)SiMe(3)(THF) (1) and (L5-H)YCH(2)SiMe(3)(THF) (2) supported by new tridentate pyridyl-1-azaallyl dianionic ligands. The reactions of monoalkyl complexes, 1 and 2, with one equivalent of 2,6-diisopropylaniline produced the corresponding monoanilide complexes, (L4-H)YNHAr(THF) (3) and (L5-H)YNHAr(THF) (4) (Ar = 2,6-((i)Pr)(2)C(6)H(3)), via highly selective protonolysis of the terminal alkyl Y-CH(2)SiMe(3) bond. Complexes 1-4 are active for intramolecular hydroamination of aminoalkenes.     

Scandium terminal imido complex induced C-H bond selenation and formation of an Sc-Se bond

The reaction between scandium terminal imido complexes and elemental selenium showed an unprecedented C-H bond selenation and the formation of an Sc-Se bond.     

Unifying metal- and organocatalysis for asymmetric oxidative iminium activation: a relay catalytic system enabling the combined allylic oxidation of alcohols and prolinol ether catalyzed iminium reactions

A multicatalytic system consisting of tetrapropylammonium perruthenate/N-methylmorpholine N-oxide (TPAP/NMO) as oxidant, and diarylprolinol TMS-ether as chiral amine catalyst, has been developed and applied in the efficient construction of valuable chiral molecules. The one-pot domino reactions elaborated in the present study are based on the in situ generation of α,β-unsaturated aldehydes from allylic alcohols and their subsequent use in various asymmetric transformations (e.g., cyclopropanation, Michael addition, Michael addition/acetalization). TPAP as a substrate-selective redox catalyst is well tolerated by the amine catalyst and the domino reactions proceed in good yields and high enantioselectivities. The compatibility of metal and organocatalysis presented herein widens the scope of asymmetric iminium catalysis.     

Unifying Metal‐ and Organocatalysis for Asymmetric Oxidative Iminium Activation: A Relay Catalytic System Enabling the Combined Allylic Oxidation of Alcohols and Prolinol Ether Catalyzed Iminium Reactions

A multicatalytic system consisting of tetrapropylammonium perruthenate/N‐methylmorpholine N‐oxide (TPAP/NMO) as oxidant, and diarylprolinol TMS‐ether as chiral amine catalyst, has been developed and applied in the efficient construction of valuable chiral molecules. The one‐pot domino reactions elaborated in the present study are based on the in situ generation of α,β‐unsaturated aldehydes from allylic alcohols and their subsequent use in various asymmetric transformations (e.g., cyclopropanation, Michael addition, Michael addition/acetalization). TPAP as a substrate‐selective redox catalyst is well tolerated by the amine catalyst and the domino reactions proceed in good yields and high enantioselectivities. The compatibility of metal and organocatalysis presented herein widens the scope of asymmetric iminium catalysis.     

Reactivity of scandium terminal imido complexes towards metal halides

Reactions of scandium terminal imido complexes with CuI and [M(COD)Cl](2) (M = Rh, Ir) show two interesting reaction patterns, and the formed heterobimetallic complexes have intriguing structural features and show promising catalytic properties.     

Ligand-induced Assembly of Copper Nanoclusters with Enhanced Electrochemical Excitation and Radiative Transition for Electrochemiluminescence**

Copper nanoclusters (CuNCs) are emerging electrochemiluminescence (ECL) emitters with unique molecule-like electronic structures, high abundance, and low cost. However, the synthesis of CuNCs with high ECL efficiency and stability in a scalable manner remains challenging. Here, we report a facile gram-scale approach for preparing self-assembled CuNCs (CuNCs_Assy) induced by ligands with exceptionally boosted anodic ECL and stability. Compared to the disordered aggregates that are inactive in ECL, the CuNCs_Assy shows a record anodic ECL efficiency for CuNCs (10 %, wavelength-corrected, relative to Ru(bpy)₃Cl₂/tripropylamine). Mechanism studies revealed the unusual dual functions of ligands in simultaneously facilitating electrochemical excitation and radiative transition. Moreover, the assembly addressed the limitation of poor stability of conventional CuNCs. As a proof of concept, an ECL biosensor for alkaline phosphatase detection was successfully constructed with an ultralow limit of detection of 8.1×10⁻⁶ U/L.     

Controllable Synthesis of BiOCl with Z-Scheme (001)/(110) Facet Homojunction and their Photocatalytic Killing Effect on HePG2 Cells in vitro

In this study, a set of BiOCl with controllable ratios of (001) and (110) facets was prepared by adjusting the content of diethylene glycol (DEG) during the preparation process. The degradation experiment of bisphenol A (BPA) shows that under simulated sunlight, when the ratio of (001) to (110) is 0.61, BiOCl (BOC-2) has the best degradation activity, which can degrade 96.2% BPA within 20 min. After theoretical calculations and experimental characterization, a Z-scheme (001)/(110) facet homojunction is proposed. Then, three typical samples were selected to test the biological toxicity of HepG2 cells and the activity of killing HepG2 cells under ultraviolet light conditions. Studies have found that exposed facets play a more important role in the biotoxicity of BiOCl to cells; with a (001)/(110) ratio of 0.61, BOC-2 exhibits excellent endocytosis and phototoxicity but no obvious dark cytotoxicity, while with a (001)/(110) ratio of 0.15, BiOCl (BOC-4) has poor endocytosis and strong cytotoxicity under dark conditions. Through reactive oxygen species (ROS) and lactate dehydrogenase (LDH) assay detection, the process of photocatalytic killing cells of BOC-2 more looks like an apoptosis mechanism, while BOC-4 mainly causes cell necrosis.