14‐Vertex Heteroboranes with 14 Skeletal Electron Pairs: An Experimental and Computational Study

Three isomers of [(Cp*Ru)₂C₂B₁₀H₁₂], the first examples of 14‐vertex heteroboranes containing 14‐skeletal electron pairs, have been synthesized by the direct electrophilic insertion of a {Cp*Ru⁺} fragment into the anion [4‐Cp*‐4,1,6‐RuC₂B₁₀H₁₂]^?. All three compounds have the same unique polyhedral structure having an approximate C_s symmetry and featuring a four‐atom trapezoidal face. X‐ray diffraction studies could confidently identify only one of the two cage C atoms in each structure. The other C atom position has been established by a combination of i) best fitting of computed and experimental ¹¹B and ¹H NMR chemical shifts, and ii) consideration of the lowest computed energy for series of isomers studied by DFT calculations. In all three isomers, one cage C atom occupies a degree‐4 vertex on the short parallel edge of the trapezium.     

Effect of salts on synthesis of mesoporous materials with mixed cationic and anionic surfactants as templates

Mesoporous silica materials were synthesized using tetraеthoxysilane as precursor and liquid crystals formed in aqueous mixtures of cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) as templates, without and with the addition of NaBr or Na₂SO₄. For this purpose, the formation of liquid crystals as a function of the ratio of CTAB and SDS under different conditions was studied. It was found that liquid crystals formed in the mixed system of CTAB and SDS at certain mixing ratios are well-structured templates for the synthesis of mesoporous silicas. The synthesized silica materials were characterized by transmission electron microscope and nitrogen adsorption/desorption analysis. The pore size of mesoporous silicas could be controlled between 3 to 6 nm by simply changing the concentration of NaBr in solution. The mesoporous silicas exhibited lamellar structure and the order of structural arrangement was promoted with addition of NaBr. However, addition of Na₂SO₄ led to ink-bottle type pores of mesoporous silica with a narrow pore size distribution of around 2 nm and a higher specific surface area of 610 m² g^–1.     

Asymmetric Construction of Pyrrolidines Bearing a Trifluoromethylated Quaternary Stereogenic Center via CuI‐Catalyzed 1,3‐Dipolar Cycloaddition of Azomethine Ylides with β‐CF3‐β,β‐Disubstituted Nitroalkenes

A direct and convenient method has been developed for the synthesis of optically active pyrrolidines bearing a quaternary stereogenic center containing a CF₃ group at the C‐3 position of the pyrrolidine ring. The synthesis system, Cu^I/Si‐FOXAP‐catalyzed exo‐selective 1,3‐dipolar cycloaddition of azomethine ylides with β‐CF₃‐β,β‐disubstituted nitroalkenes, provides pyrrolidines with high diastereoselectivities (up to >98:2 d.r.) and excellent enantioselectivities (up to >99.9 ee) and performs well for a broad scope of substrates under mild conditions.     

Low‐Temperature Cationic Rearrangement in a Bulk Metal Oxide

Cationic rearrangement is a compelling strategy for producing desirable physical properties by atomic‐scale manipulation. However, activating ionic diffusion typically requires high temperature, and in some cases also high pressure in bulk oxide materials. Herein, we present the cationic rearrangement in bulk Mn₂FeMoO₆ at unparalleled low temperatures of 150–300 ^oC. The irreversible ionic motion at ambient pressure, as evidenced by real‐time powder synchrotron X‐ray and neutron diffraction, and second harmonic generation, leads to a transition from a Ni₃TeO₆–type to an ordered‐ilmenite structure, and dramatic changes of the electrical and magnetic properties. This work demonstrates a remarkable cationic rearrangement, with corresponding large changes in the physical properties in a bulk oxide at unprecedented low temperatures.     

脉冲LD泵浦电光调Q深紫外激光器

研制了千赫兹213 nm深紫外全固态激光器。激光器采用脉冲LD侧面泵浦方式和电光调Q技术,实现了10瓦级基频光的稳定输出。利用多次倍频技术,实现了稳定的213 nm深紫外激光输出。当LD泵浦电流为80 A时,213 nm激光输出的最大平均功率达到了151 m W,激光器重复频率为1 k Hz,激光脉冲宽度为10ns,功率不稳定度为3%。同时,对激光在非线性晶体中的偏振匹配和不同重复频率条件下的激光器运转特性进行了分析。     

Evolution and Entanglement of Gaussian States in the Parametric Amplifier

We obtain the linear time-dependent constants of motion of the parametric amplifier and use them to determine the evolution of a general two-mode Gaussian state in the tomographic-probability representation. By means of the discretization of the continuous variable density matrix, we calculate the von Neumann and linear entropies to measure the entanglement properties between the modes of the amplifier. We compare the obtained results for the nonlocal correlations with those associated to a linear map of discretized symplectic Gaussian-state tomogram onto a qubit tomogram. We use this qubit portrait procedure to establish Bell-type inequalities, which provide a necessary condition to determine the separability of quantum states, which can be evaluated through homodyne detection. We define the other no-signaling nonlocal correlations through the portrait procedure for noncomposite systems.     

Heisenberg型群上的仿积算子

首先给出了Heisenberg型群上一类仿积算子的定义,研究了该算子的L~2→L~2有界性.其次探讨了Heisenberg型群上的Calderon-Zygmund算子,包括该算子的L~p→L~p有界性,L~1→L~(1,∞)有界性以及H~1→L~1有界性.最后证明了仿积算子也是Calderon-Zygmund算子,同时还证明了仿积算子的一些其它重要性质.     

Bulk Passivation Enables Hundredfold-Enhanced Electroluminescence of Monophosphine Cu4I4 Cubes

Electroluminescent (EL) clusters emerged rapidly, owing to their organic–inorganic hybrid character useful for comprehensive performance integration and the potential for large-scale display and lighting applications. However, despite their good photoluminescent (PL) properties, until present, no efficient EL monodentate ligand-based clusters were reported due to structural variation during processing and excitation and exciton confinement on cluster-centered quenching states. Here we demonstrate an effective bulky passivation strategy for efficient cluster light-emitting diodes with a monophosphine Cu₄I₄ cube named [TMeOPP]₄Cu₄I₄. With terminal pyridine groups, an active matrix named TmPyPB supports an effective host-cluster interplay for configuration fixation, structural stabilization, and exciton-confinement optimization. Compared to common inactive hosts, the passivation effects of TmPyPB markedly reduce trap-state densities by 24–40 % to suppress nonradiative decay, resulting in state-of-the-art PL and EL quantum yields reaching 99 % and 15.6 %, respectively, which are significantly improved by about 7-fold. TmPyPB simultaneously increases EL luminance to 10⁴ nits, which is ≈100-fold that of the non-doped analogue.     

Regulated Ion/Electron-Conducting Interphase Enables Stable Zinc-Metal Anodes for Aqueous Zinc-Ions Batteries

Metallic Zinc (Zn) is considered as a remarkably promising anode for aqueous Zn-ion batteries due to its high volumetric capacity and low redox potential. Unfortunately, dendritic growth and severe side reactions destabilizes the electrode/electrolyte interface, and ultimately reduce the electrochemical performance. Here, an artificial protective layer (APL) with a regulated ion and electron-conducting interphase is constructed on the Zn-metal anode to provide excellent interfacial stability in high-rate cycling. The superior ionic and moderate electronic conductivity of the APL derives from the co-embedding of MXene and Zn(CF₃SO₃)₂ salts into the polyvinyl alcohol hydrogel, which enables a synergistic effect of local current density reduction during plating and ion transport acceleration during stripping for Zn anode. Furthermore, the high Young's modulus of the protective layer and dendrite-free deposition morphology during cycling suppresses hydrogen evolution reactions (2.5 mmol h⁻¹ cm⁻²) and passivation. As a result, in symmetrical cell tests, the modified battery presents a stable life of over 2000 cycles at ultra-high current density of 20 mA cm⁻². This research presents a new insight into the formation and regulation of stable electrode-electrolyte interface for the Zn-metal anode.     

Niobium Bis- and Mono(Pentafulvene) Complexes: E−H Bond Cleavage and Insertion Reactions (E=C,N, O)

Bis(η⁵:η¹-(di-para-tolyl)pentafulvene)niobium chloride ( 1 ) reacts with methyl lithium via salt metathesis to the methylated bis(pentafulvene)niobium complex 2 , and with lithium 2,6-diisopropylanilide addition and subsequent N−H bond activation to the imido mono(pentafulvene)niobium complex 3 . Avoiding the competing protonation of the chloride, bis(pentafulvene)niobium complex 2 reacts with primary aromatic and aliphatic amines to form terminal niobocene imido complexes, and with water to form the analog terminal oxo complex. Secondary methyl amines undergo a simultaneous N−H and C−H activation to form niobaaziridines under mild conditions. In contrast to other reported examples, 3 can be employed to investigate the uncontested reactivity of mono(pentafulvene)niobium complexes. Reaction with 4-tert-butylphenol selectively yields a niobocene phenolate complex. Unprecedented for mono(pentafulvene)niobium complexes, treating 3 with multiple-bond-containing substrates (nitriles, isocyanates) smoothly results the insertion into the Nb-C_exo σ-bond, forming the corresponding alkylidene amido and imidato complexes.