Transition Metal Induced Pentamerization of a Phosphaalkyne

The metalla-norbornadiene complex 1, extended by two phosphaalkyne units in the 1,4-position, is formed by an unprecedented pentamerization of the phosphaalkyne MesC identical withP (Mes=2,4,6-Me(3)C(6)H(2)) in the coordination sphere of the transition metal complex [W(CO)(5)(thf)].     

Ultra-Weak Metal−Metal Bonding: Is There a Beryllium-Beryllium Triple Bond?

Metal-metal triple bonds featuring s-block element have not been reported until now. Only Be−Be double bonds between have been predicted theoretically based on the intuitive electron donation from four s¹ type electron-donating ligands. Herein, we theoretically predicted a novel species featuring a Be−Be triple bond in the Li₆Be₂ molecule. The molecule was found to be thermodynamically stable. The presence of the triple bond was confirmed by adaptive natural density partitioning (AdNDP), electron localization function (ELF), and atoms in molecules (AIM) analyses. Moreover, the mechanical strength of the Be−Be triple bond was analyzed by using compliance matrix, pointing towards its ultra-weak nature.     

Structural Phase Transitions of a Molecular Metal Oxide

The structural phase of a metal oxide changes with temperature and pressure. During phase transitions, component ions move in multidimensional metal–oxygen networks. Such macroscopic structural events are robust to changes in particle size, even at scales of around 10 nm, and size effects limiting these transitions are particularly important in, for example, high-density memory applications of ferroelectrics. In this study, we examined structural transitions of the molecular metal oxide [Na@(SO₃)₂(n-BuPO₃)₄Mo^V₄Mo^VI₁₄O₄₉]⁵⁻ (Molecule 1 ) at approximately 2 nm by using single-crystal X-ray diffraction analysis. The Na⁺ encapsulated in the discrete metal-oxide anion exhibited a reversible order–disorder transition with distortion of the Mo–O molecular framework induced by temperature. Similar order–disorder transitions were also triggered by chemical pressure induced by removing crystalline solvent molecules in the single-crystal state or by substituting the countercation to change the molecular packing.     

Metal Affinity-Based Purification of a Red Fluorescent Protein

A red fluorescent protein, DsRed, which emits fluorescence in the red region of the spectrum has become a popular alternative to green fluorescent protein as a label in biochemical and bioanalytical applications. In this study, we have developed a simple purification method for DsRed variants utilizing their inherent copper binding property. A purification procedure was developed and optimized using immobilized copper ions yielding a single strong band corresponding to purified DsRed proteins on the SDS-PAGE gel. A purification efficiency of higher than 95% was achieved. A spectral analysis and copper binding study was performed to verify activity of the purified proteins. The development of this method allows DsRed to play a dual role as a fluorescent reporter protein and as a purification affinity tag for a target protein. This simpler approach of purification should expand the utility of DsRed.     

XeF4 as a Ligand for a Metal Ion

Noble molecule : [Mg(XeF₂)(XeF₄)](AsF₆)₂ is the first coordination compound in which XeF₄ acts as a ligand to a metal center. It is also the first known compound, in which XeF₂ and XeF₄ are simultaneously coordinated to the same metal center (see structure; purple Xe, green F, gray Mg, yellow As).

     

Metal fragment exchange from a molybdaborane to a tungstaborane

Reaction of the molybdaborane arachno-2-[Mo(η-C₅H₅)(η⁵:η¹-C₅H₄)B₄H₇] (I) with the electron-rich molecule [W(PMe₃)₃H₆] at 60 °C for 12 h in toluene gives the novel tungstaborane nido-2-W(PMe₃)₃H₂B₄H₇[Mo(η-C₅H₅)(η⁵:η¹-C₅H₄)H₂] (II) in 60% yield. The reaction is almost quantitative when followed by NMR. This is a rare example of metal fragment exchange within a metallaborane cage. The molybdenum atom is retained in the molecule via a σ-bond between the substituted cyclopentadienyl ring and a basal boron atom in the metallaborane cluster.     

Intercalation of Highly Dispersed Metal Nanoclusters into a Layered Metal Oxide for Photocatalytic Overall Water Splitting

Metal nanoclusters (involving metals such as platinum) with a diameter smaller than 1 nm were deposited on the interlayer nanospace of KCa₂Nb₃O₁₀ using the electrostatic attraction between a cationic metal complex (e.g., [Pt(NH₃)₄]Cl₂) and a negatively charged two‐dimensional Ca₂Nb₃O₁₀^? sheet, without the aid of any additional reagent. The material obtained possessed eight‐fold greater photocatalytic activity for water splitting into H₂ and O₂ under band‐gap irradiation than the previously reported analog using a RuO₂ promoter. This study highlighted the superior functionality of Pt nanoclusters with diameters smaller than 1 nm for photocatalytic overall water splitting. This material shows the greatest efficiency among nanosheet‐based photocatalysts reported to date.     

金属配合物作为核酸释放的载体

基因治疗是指利用一种载体将健康的基因载入细胞替换致病的基因.由基因缺陷导致的人类疾病达1200多种,最合理的选择是采用基因替换的方法进行治疗.基因治疗的关键问题是解决"使用何种载体才能安全有效地将治疗基因载入靶细胞".非病毒基因载体主要是一些有机阳离子物种,一直受到极大重视;近年来,磷酸钙、纳米粒子和金属配合物释放核酸的功能也开始受到关注.本文总结了金属配合物作为非病毒基因载体使用的研究进展,希望由此理解配合物释放核酸的优势和不足之处.     

Complexes with a Metal Phosphorus Triple Bond

Herein we report the synthesis of different phosphido-complexes and -intermediates with WLE-triple bond. These compounds reveal different reactivity patterns. Details of reactivity as well as spectroscopic and theoretical aspects will be discussed in detail.     

Metal cages using a bulky phosphonate as a ligand

The synthesis, structure, magnetic and electronic properties of soluble transition metal phosphonate cages utilizing tritylphosphonic acid (TPA) as ligand are reported.     

Exceeding Metal Capacity in Sandwich Complexes: Ligand‐Unsupported Docking of Extra Metal Moieties at Edges of a Metal Sheet Sandwich Complex

The ligand‐unsupported accommodation of extra metal moieties in a sandwich complex is reported. Although it has been considered that the metal‐capacity of a metal sheet sandwich complex is strictly limited by the size of cyclic unsaturated hydrocarbon ligands, the M?M edge bonds in a metal sheet sandwich complex provide a ligand‐unsupported docking site for extra metal moieties, allowing expansion of metal‐capacity in sandwich complexes. The metal sheet sandwich complex [Pd₄(μ₄‐C₈H₈)(μ₄‐C₉H₉)]⁺, in which the ligand‐based metal capacity is full in terms of the usage of all C=C moieties of the smaller carbocyclic ligand C₈H₈ in coordination, can accommodate extra M⁰{P(OPh)₃}₂ (M=Pd, Pt) moieties without coordinative assistance by either the C₉H₉ or the C₈H₈ ligand.     

Fabrication of Porous Metal Oxide Semiconductor Films by a Self-Template Method Using Layered Hydroxide Metal Acetates

Porous metal oxide (Co₃O₄, NiO, or ZnO) films were fabricated by a self-template method using layered hydroxide metal acetates (LHMA; metal = Co, Ni, or Zn) as templates. LHMAs were initially grown on glass substrates through a chemical bath deposition in methanolic-aqueous solutions of metal acetates at 60°C. The template films had a unique, nest-like morphology consisting of interlaced flake-like particles as a result of two-dimensional crystal growth of LHMAs in supersaturated solutions. The templates were successfully converted into porous Co₃O₄, NiO, or ZnO films by heating at 500°C for 10 min in air without microstructural deformation.     

Metal nitrite: a powerful oxidizing reagent

An efficient and simple source of nitroso reagents and their oxidation reactions are described. The combination of a Lewis acid and a metal nitrite was applied to the oxidation of silyl enol ethers. Amino acid and peptide derivatives were easily accessed through in situ C-C bond cleavage of fully substituted silyl enol ethers upon oxidation.     

Metal catalysed light emission from a dioxetan

The photosensitised oxidation of 9- (2-adamantylidene)-N-methylacridan affords a compound whose properties are best explained by a dioxetan structure. Its decomposition is catalysed by lanthanide chelates with energy transfer.     

ProPhenol Derived Ligands to Simultaneously Coordinate a Main-Group Metal and a Transition Metal: Application to a Zn−Cu Catalyzed Reaction

A new bifunctional ligand bearing chiral N-heterocyclic carbene (NHC) and prolinol moieties is presented. Utilizing the designed ligand, an in situ formed Cu/Zn hetero-bimetallic complex unlocks the asymmetric allylic alkylation reactions of allyl phosphates with zinc keto-homoenolates, leading to the formation of various γ-vinyl ketones with good regio- and enantio-selectivity. DF sT calculation supports that the chelation of allyl phosphates with catalyst promotes the S_N2’ addition and the ligand-substrate steric interactions account for the stereoselective outcome.