Dipnictogen Radical Chemistry: A Dithorium-Supported Distibene Radical Trianion.

Although two examples of σ-bonded -bent [RSbSbR] (R = bulky organo- or Ga-groups) that formally contain the Sb radical trianion moiety are known in p-block chemistry, d- or f-element Sb radical trianion complexes, with or without R-substituents, have remained elusive. Here, we report that reduction of a 77:23 mix of [{Th(Tren)}(μ-η:η-Sb)] (, Tren = {N(CHCHNSiPr)}):[{Th(Tren)}(μ-SbH)] () with 1.5 equiv of KC in the presence of 1.

Chiral-at-metal catalysts: history, terminology, design, synthesis, and applications.

For decades, advances in chiral transition metal catalysis have been closely tied to the development of customized chiral ligands. Recently, however, an alternative approach to this traditional metal-plus-chiral-ligand method has emerged. In this new strategy, chiral transition metal catalysts are composed entirely of achiral ligands, with the overall chirality originating exclusively from a stereogenic metal center.

Isolation of a planar π-aromatic Bi ring in a cobalt-based inverse-sandwich-type complex.

Monocyclic π-aromatic compounds are ubiquitous throughout almost all fields of natural sciences-as synthons in industrial processes, as ligands of metal complexes for catalysis or sensing and as bioactive molecules. Planar organocycles stand out through their specific way of overcoming electron deficiency by a non-localizable set of (4n + 2)π electrons. By contrast, all-metal aromatic monocycles are still rare, as metal atoms prefer to form clusters with multiply bonded atoms instead.

pH-sensitive polyglycerol nanogels for periodontitis treatment through antibacterial and pro-angiogenesis action.

Periodontitis is a microbe-driven inflammatory disease leading to bone resorption and tissue destruction. We propose a dual-functional nanogel complex armed with the antimicrobial drug triclosan (TCS) and the pro-angiogenesis medication deferoxamine (DFO) for combating microbial pathogens and promoting tissue regeneration. The nanogel system (NG-TCS-DFO) that we fabricated from linear polyglycerol exhibits well-defined spherical morphology and a positively charged surface for bacteria adhesion.

On-Surface Synthesis and Characterization of Pentadecacene and Its Gold Complexes.

Acenes are an important class of polycyclic aromatic hydrocarbons that have gained considerable attention from chemists, physicists, and material scientists, due to their exceptional potential for organic electronics. They serve as an ideal platform for studying the physical and chemical properties of sp carbon frameworks in the one-dimensional limit and also provide a fertile playground to explore magnetism in graphenic nanostructures due to their zigzag edge topology. While higher acenes up to tridecacene have been successfully generated by means of on-surface synthesis, it is imperative to extend their synthesis toward even longer homologues to comprehensively understand the evolution of their electronic ground state.

Energy Landscapes in Chemical Reactions and Transport.

Both, molecular chemical reactions and transport of atoms in solid media are determined by the energy landscape in which the seemingly different processes take place. Chemical reactions can be described as cooperative translocation of two chemical entities on a common potential energy surface. Transport of atoms in a solid can be envisaged as the translocation of a single particle in the potential energy landscape of all other particles constituting the solid.

Intramolecular Agostic Interactions and Dynamics of a Methyl Group at a Preorganized Dinickel(II) Site.

Alkyl nickel intermediates relevant to catalytic processes often feature agostic stabilization, but relatively little is known about the situation in oligonickel systems. The dinickel(I) complex K[LNi], which is based on a compartmental pyrazolato-bridged ligand L with two β-diketiminato chelate arms, or its masked version, the dihydride complex [KL(Ni-H)] that readily releases H, oxidatively add methyl tosylate to give diamagnetic [LNi(CH)] () with (Ni···Ni) ≈ 3.7 Å.

Isolation and Structure Elucidation of the Heterocumulene Anions [NCC-L] (L=CO, CS, N).

Cumulenes are molecules characterized by a series of consecutive double bonds. They serve as important reagents and intermediates in the synthesis of polymers and a wide variety of functionalized compounds, including various heterocycles. Understanding the properties of cumulenes and developing synthetic routes to these often highly reactive species is essential for unlocking new applications.

Coordination-induced axial chirality controls the metal-centred configuration in a stereogenic-at-iron catalyst.

A new approach is introduced to control the metal-centred configuration of stereogenic-at-iron catalysts by utilizing axial ligand chirality, which becomes locked upon metal coordination. This strategy is applied to an iron catalyst containing two chelating -(2-pyridyl)-substituted triazol-5-ylidene mesoionic carbenes (MICs) resulting in a helical topology with a stereogenic iron centre.

Spectroscopy and Bonding Analysis of ArBO ( = 1-3) Cations That Possess Argon-Boron Multiple Bonds.

ArBO ( = 1-3) complexes have been prepared and subjected to spectroscopic characterization in the gas phase. Mass-selected infrared photodissociation spectroscopy, in combination with theoretical calculations, reveals the coexistence of two nearly isoenergetic structural isomers in ArBO. One isomer entails two equivalent Ar atoms chemically bound to BO, while the other features an ArBO core ion accompanied by a weakly tagging argon atom.

Neutral 4π-electron tetrasilacyclobutadiene contains unusual features of a Möbius-type aromatic ring.

The search for stable compounds containing an antiaromatic cyclic 4π system is a challenge for inventive chemists that can look back on a long history. Here we report the isolation and characterization of the novel 4π-electron tetrasilacyclobutadiene, an analogue of a 4π neutral cyclobutadiene that exhibits surprising features of a Möbius-type aromatic ring. Reduction of RSiCl (R = (Pr)PCH) with KC in the presence of cycloalkyl amino-carbene (cAAC) led to the formation of corresponding silylene 1.

π-Lewis Base Activation of Carbonyls and Hexafluorobenzene.

We report hitherto elusive side-on η-bonded palladium(0) carbonyl (anthraquinone, benzaldehyde) and arene (benzene, hexafluorobenzene) palladium(0) complexes and present the catalytic hydrodefluorination of hexafluorobenzene by cyclohexene. The comparison with respective cyclohexene, pyridine and tetrahydrofuran complexes reveals that the experimental ligand binding strengths follow the order THF View Article and Find Full Text PDF

Sulfonatocalix[4]arene-Based Scavengers for V-Type Nerve Agents with Enhanced Detoxification Activity.

Synthetic small molecule scavengers that rapidly detoxify nerve agents in vivo allow (pre)treatment of nerve agent poisoning. However, scavengers that detoxify persistent V-type nerve agents at pH 7.4 and 37 °C with sufficient efficiency are still unknown.

Synthesis of Lewis Acid-Base Adducts Between Potassium Dihydrogenpnictogenides and Group 13 Lewis Acids.

Lewis acid-base adducts between potassium dihydrogenpnictogenides [K(18c6)PnH] (Pn=P, As) and Trialkylgallanes (GaMe, GaEt, GatBu) as well as BH were synthesized. In the course of these investigations, we were able to fully characterize a row of compounds of the type [K(18c6)(thf)][PnH(ER)] (E=B: R=H; E=Ga: R=Me, Et, tBu). Based on the successful syntheses of these species, we also synthesized several compounds of the composition [K(18c6)(thf)][Pn(SiMe)(ER)] (n=1, 2) starting from [KPn(SiMe)] (Pn=P and As) and ER (E=B, Al, In: R=Me; E=Ga: R=Me, Et, tBu).

Neutral Phosphorus-Based Beryllium Scorpionate Complexes as Spectroscopic Probes for Base Strength and Electron Donation.

The synthesis and properties of tris(diisopropylphosphanylmethyl)phenylborate ([TP(Pr)]) beryllium complexes [TP(Pr)]Be with = Cl, Br, I, CN, SCN, OCN, N, and CFSO are described. In these compounds, the NMR coupling constant can be used as a sensitive probe for the basicity and electron-donating properties of the anions in solution.

Biosynthesis of Tetramate Derivatives in Reveals the Involvement of -Quinone Methide in Crosstalk of Multiple Pathways.

Genome mining and gene deletion experiments in proved the involvement of the PKS-NRPS PemA and the -enoyl reductase PemB in the formation of three enantiomeric clavatol-containing tetramate pairs. Overexpression of a transcription factor significantly improved the product yields. Feeding experiments provided evidence for their formation via 1,4-Michael addition of hydroxyclavatol to two tetramates from the Pem pathway.

Calculation of divergenceless magnetically induced current density in molecules.

A method for the calculation of divergenceless, magnetically induced quantum mechanical current densities in molecules that approximates the exact current is presented. This was achieved by adding to the calculated conventional current density, i.e.

Synthesis of Iron(IV) Alkynylide Complexes and Their Reactivity to Form 1,3-Diynes.

The isolation of thermally unstable and highly reactive organoiron(IV) complexes is a challenge for synthetic chemists. In particular, the number of examples where the C-based ligand is not part of the chelating ligand remains scarce. These compounds are of interest because they could pave the way to designing catalytic cycles of bond forming reactions proceeding via organoiron(IV) intermediates.

Removal, mechanistic and kinetic studies of Cr(VI), Cd(II), and Pb(II) cations using FeO functionalized Schiff base chelating ligands.

The Schiff base chelating ligands; (E)-2-(3,3-dimethoxy-2-oxa-7,10-diaza-3-silaundec-10-en-11-yl)phenol (L1), (E)-N-(2-((pyridine-2ylmethylene)amino)ethyl)-3-(trimethoxysilyl)propan-1-amine (L2) and (E)-N-(2-((thiophen-2-ylmethylene)amino)ethyl)-3-(trimethoxysilyl)propan-1-amine (L3) were immobilized on FeO magnetic nanoparticles (MNPs) and utilized in the extraction of Cr(VI), Cd(II) and Pb(II) metal cations from aqueous solutions. The compounds synthesized, denoted as L1@ FeO, L2@FeO, and L3@FeO, were characterized using FT-IR spectroscopy, TEM-SEM, VSM, and BET/BHJ techniques for analysis of functional groups, surface morphology, magnetic properties, and degree of porosity of the adsorbents, respectively. BET/BHJ technique confirmed the mesoporous nature of the compounds as their pore diameters ranged between 15 and 17 nm.

The Trifluorooxygenate Anion [OF]: Spectroscopic Evidence for a Binary, Hypervalent Oxygen Species.

Experimental evidence for hypervalent compounds of second-row elements is still scarce in literature. Here, we present the first report of the long-sought binary, hypervalent trifluorooxygenate anion [OF]. It was isolated in solid Ne matrices under cryogenic conditions after reacting oxygen difluoride with free fluoride ions from laser ablation of alkali metal fluorides MF (M=Li-Cs).

Long ranged stress correlations in the hard sphere liquid.

The smooth emergence of shear elasticity is a hallmark of the liquid to glass transition. In a liquid, viscous stresses arise from local structural rearrangements. In the solid, Eshelby has shown that stresses around an inclusion decay as a power law r-D, where D is the dimension of the system.

Thermolysis of CsO ( = In, Sc): Synthesis, Crystal Structure, Chemical Bonding, and Reactivity of the Subvalent Oxidometalates CsO ( = In, Sc).

The cesium-poor alkali-metal suboxidometalates CsO ( = In, Sc) were prepared from the respective cesium-rich suboxidometalates CsO by thermolysis in a dynamic vacuum at temperatures below 150 °C. They crystallize in a new structure type, comprising isolated tetrahedral oxidometalate anions [O] immersed in a matrix of metallic cesium atoms. This structural separation into alternating ionic and metallic building units is typical for subvalent compounds.