Bottom-Up Synthesis of Metallic CoNi Nanoplatelets with Magnetic Vortex-Like Spin Configurations.

Magnetic nanoplatelets hold significant potential for various technical applications due to their ability to switch between a fully magnetized state with high magnetization and a vortex-like configuration that eliminates stray fields in the absence of an external field. This study presents the synthesis of uniform CoNi nanoplatelets through the topotactic reduction of metal hydroxides using hydrogen plasma. The reduction process is analyzed via magnetometry, leveraging the transition from paramagnetic hydroxide to ferromagnetic metal.

Morphological Degradation of Oxygen Evolution Reaction-Electrocatalyzing Nickel Selenides at Industrially Relevant Current Densities.

We investigated electrodeposited nanoparticulate nickel selenide (pre)catalysts that transform into nickel oxides/oxyhydroxides under oxygen evolution reaction conditions in alkaline solutions. Previous studies of this transformation were conducted at lower current densities than those of industrial relevance (≥1 A cm). We used ultramicroelectrodes (UMEs) to achieve such current densities, benefiting from their small size, ensuring low absolute currents and low ohmic drop but high current densities.

Synthesis and Reactivity of a Mono-Coordinated Triplet Bismuthinidene.

The triplet bismuthinidene Ar*Bi (4) stabilized by a very bulky septiphenyl ligand (Ar* = 3,5-i-Pr-2,6-(2,6-Me-3,5-(2,6-i-PrCH)-CH)-CH) was synthesized by dehydrogenation of in situ formed bismuth dihydride Ar*BiH (3). Oxidative addition reactions of 4 with alkyl halides (MeI, EtBr, i-PrBr) yielded bismuthanes Ar*Bi(Me)I (5), Ar*Bi(Et)Br (6), and Ar*Bi(i-Pr)Br (7), which reacted with LiAlH and LiAlD to the thermally robust bismuth monohydrides Ar*Bi(R)H (R = Me 8, Et 10, i-Pr 12) and monodeuterides Ar*Bi(R)D (R = Me 9, Et 11, i-Pr 13). Ar*Bi(NMe) 1 and Ar*BiH 3 were characterized in situ by H NMR spectroscopy and sc-XRD (1), whereas the other compounds were characterized by heteronuclear NMR (H/H (D), C) and IR spectroscopy, elemental analysis (Ar*-2, Ar*-3, Ar*-5, Ar*-7, Ar*I, Ar*H, 2, 4-7), as well as by UV-vis (4) and sc-XRD (Ar*-7, Ar*I, Ar*Li·Lit-Bu, Ar*H, 1, 2, 4, 12).

Synthesis and reactivity of a six-membered heterocyclic 1,3-diphosphaallene.

1,3-Diphosphaallenes are a new class of heavier heteroallenes and show a fascinating chemical behavior and reactivity. Herein we report on the room temperature transformation of gallaphosphene LGa(OCP)PGaL 1 (L = HC[C(Me)N(Ar)], Ar = 2,6-i-PrCH) to the six-membered metallaheterocycle LGa(PCP)OGaL 2 featuring a LGa-substituted 1,3-diphosphaallene unit. The possible mechanism of formation of 2 is supported by quantum chemical calculations, which revealed that the formation of 2 is energetically more favorable ( 2 kcal mol) than the formation of 1 at ambient temperature.

Infiltration of secondary treated wastewater into an oxic aquifer: Hydrochemical insights from a large-scale sand tank experiment.

To mitigate groundwater level decline, managed aquifer recharge (MAR) with secondary treated wastewater (STWW) is increasingly considered and implemented. However, the effectiveness and potential risks of such systems need evaluation prior to implementation. In this study, we present a large-scale sand tank experiment to analyse processes related to the infiltration of real STWW through the vadose zone and subsequent mixing with oxic native groundwater.

An Integrated Photonic Biosensing Platform for Pathogen Detection in Aquaculture.

Aquaculture is expected to play a vital role in solving the challenge of sustainably providing the growing world population with healthy and nutritious food. Pathogen outbreaks are a major risk for the sector, so early detection and a timely response are crucial. This can be enabled by monitoring the pathogen levels in aquaculture facilities.

Competitive sorption experiments reveal new regression models to predict PhACs sorption on carbonaceous materials.

Sorption of hydrophobic organic contaminants onto thermally altered carbonaceous materials (TACM) constitutes a widely used technology for remediation of polluted waters. This process is typically described by sorption isotherms, with one of the most used models, the Polanyi-Dubinin-Manes (PDM) equation, including water solubility (S) as a normalizing factor. In case of pharmaceutical active compounds (PhACs), S depends on the pH of the environment due to the ionic/ionizable behavior of these chemicals, a fact frequently ignored in sorption studies of PhACs.

Catalytic hydroboration of aldehydes and ketones with an electron-rich acyclic metallasilylene.

The application of main group metal complexes in catalytic reactions is of increasing interest. Here we show that the electron-rich, acyclic metallasilylene L'(Cl)GaSiL C (L' = HC[C(Me)NDipp], Dipp = 2,6-PrCH; L = PhC(NBu)) acts as a precatalyst in the hydroboration of aldehydes with HBPin. Mechanistic studies with iso-valeraldehyde show that silylene C first reacts with the aldehyde with [2 + 1] cycloaddition in an oxidative addition to the oxasilirane 1, followed by formation of the alkoxysilylene LSiOCH[Ga(Cl)L']CHCHMe (2), whose formation formally results from a reductive elimination reaction at the Si center.

Role of Fe decoration on the oxygen evolving state of CoO nanocatalysts.

The production of green hydrogen through alkaline water electrolysis is the key technology for the future carbon-neutral industry. Nanocrystalline CoO catalysts are highly promising electrocatalysts for the oxygen evolution reaction and their activity strongly benefits from Fe surface decoration. However, limited knowledge of decisive catalyst motifs at the atomic level during oxygen evolution prevents their knowledge-driven optimization.

Metal-metal cooperativity boosts Lewis basicity and reduction properties of the bis(gallanediyl) LGa.

The interplay of two proximate gallium centres equips the bimetallic complex LGa (1, L = 1,2--Cy[NC(Me)C(H)C(Me)N(Dip)], Dip = 2,6-i-PrCH) with increased Lewis basicity and higher reducing power compared to the monometallic gallanediyl LGa (2, L = HC[MeCN(Dip)]) as evidenced by cross-over experiments. Quantum chemical calculations were employed to support the experimental findings.

From Neutral Diarsenes to Diarsene Radical Ions and Diarsene Dications.

Diarsene [L(MeO)GaAs] (L=HC[C(Me)N(Ar)], Ar=2,6-PrCH, 4) reacts with MeOTf and NHC (NHC=1,3,4,5-tetra-methylimidazol-2-ylidene) to the diarsene [L(TfO)GaAs] (5) and the carbene-coordinated diarsene [L(MeO)GaAsAs(NHC)Ga(OMe)L] (6). The NHC-coordination results in an inversion of the redox properties of the diarsene 4, which shows only a reversible reduction event at E=-2.06 V vs Fc, whereas the carbene-coordinated diarsene 6 shows a reversible oxidation event at E=-1.

Activation of non-polar bonds by an electron-rich gallagermylene.

The electron-rich germylene LGa(μ-Cl)GeAr (1) (L = CH[C(Me)N(Dipp)], Dipp = 2,6-PrCH, Ar = 2,6-MesCH, Mes = 2,4,6-MeCH) shows promising potential in the σ-bond activation of unpolar molecules as is shown in oxidative addition reactions with H and P, yielding L(Cl)GaGe(H)Ar (2) and L(Cl)Ga(P)GeAr (3). Compounds 2 and 3 were characterised spectroscopically (H, C{H}, (P{H}), IR) and by single-crystal X-ray diffraction (sc-XRD).

Gallaphosphene L(Cl)GaPGaL: A novel phosphinidene transfer reagent.

Gallaphosphene L(Cl)GaPGaL 1 (L=HC[C(Me)N(Ar)]; Ar=2,6-iPrCH) reacts with N-heterocyclic carbenes NHC (NHC=[CMeN(R)]C; R=Me, iPr) to NHC-coordinated phosphinidenes NHC→PGa(Cl)L (R=Me 2 a, iPr 2 b) and with isonitriles RNC (R=iPr, Cy) to 1,3-phosphaazaallenes L(Cl)GaP=C=N-R (R=iPr 3 a, Cy 3 b), respectively. Quantum chemical calculations reveal that 2 a/2 b possess two localized lone pair of electrons, whereas 3 a/3 b only show one localized lone pair as was reported for gallaphosphene 1. 2 b reacts with 2.

Structural characterization and reactivity of a room-temperature-stable, antiaromatic cyclopentadienyl cation salt.

The singlet states of cyclopentadienyl (Cp) cations are considered as true prototypes of an antiaromatic system. Unfortunately, their high intrinsic reactivity inhibited their isolation in the solid state as a salt, and controlled reactions are also scarce. Here we present the synthesis and solid state structure of the room-temperature-stable Cp cation salt [Cp(CF)][SbF].

Multiple ethylene activation by heteroleptic L(Cl)Ga-substituted germylenes.

Ethylene insertion into the Ga-Ge bond of the L(Cl)Ga-substituted germylene LGa(μ-Cl)GeDMP 1 (L = HC(C(Me)NAr), Ar = 2,6-PrCH; DMP = 2,6-MesCH, Mes = 2,4,6-MeCH) at ambient temperature is followed by dimerization of the as-formed germylene to give the digermene 3, which further reacted with ethylene in a [2 + 2] cycloaddition to give the 1,2-digermacyclobutane 4. In marked contrast, the amino-substituted germylene L(Cl)GaGeN(SiMe)Ar 2 reacted directly to the 1,2-digermacyclobutane 5. Quantum chemical calculations confirmed the assumed reaction mechanism, hence demonstrating the crucial role of the substituent on the reaction mechanism.

Homoleptic and heteroleptic ketodiiminate zinc complexes for the ROP of cyclic l-lactide.

Homo- and heteroleptic ketodiiminate zinc complexes LZn (1, L = [MeNCHNC(Me)CH]CO), L(ZnCp) (2, L = [MeNCHNC(Me)CH]CO, Cp = CH) and LHZnCp* (3, Cp* = CMe) were synthesized and characterized by H and C NMR and IR spectroscopy as well as by elemental analysis and single crystal X-ray diffraction (sc-XRD, 2, 3). The catalytical activity of heteroleptic complexes 2 and 3 were tested in the ring-opening polymerization (ROP) of l-lactide. Homobimetallic complex 2 showed the highest activity and selectivity for the synthesis of cyclic polylactide (cPLLA; TOF = 17 460 h) at 100 °C in toluene solution, while linear polymers are formed with mononuclear complex 3.

Syntheses and Structures of 5-Membered Heterocycles Featuring 1,2-Diphospha-1,3-Butadiene and Its Radical Anion.

LGa(P OC)cAAC 2 features a 1,2-diphospha-1,3-butadiene unit with a delocalized π-type HOMO and a π*-type LUMO according to DFT calculations. [LGa(P OC)cAAC][K(DB-18-c-6)] 3[K(DB-18-c-6] containing the 1,2-diphospha-1,3-butadiene radical anion 3⋅ was isolated from the reaction of 2 with KC and dibenzo-18-crown-6. 3 reacted with [Fc][B(C F ) ] (Fc=ferrocenium) to 2 and with TEMPO to [L Ga(P OC)cAAC][K(DB-18-c-6)] 4[K(DB-18-c-6] containing the 1,2-diphospha-1,3-butadiene anion 4 .

Role of Soil Biofilms in Clogging and Fate of Pharmaceuticals: A Laboratory-Scale Column Experiment.

Contamination of groundwater with pharmaceutical active compounds (PhACs) increased over the last decades. Potential pathways of PhACs to groundwater include techniques such as irrigation, managed aquifer recharge, or bank filtration as well as natural processes such as losing streams of PhACs-loaded source waters. Usually, these systems are characterized by redox-active zones, where microorganisms grow and become immobilized by the formation of biofilms, structures that colonize the pore space and decrease the infiltration capacities, a phenomenon known as bioclogging.

Metal-coordinated distibene and dibismuthene dications - isoelectronic analogues of butadiene dications.

We report the synthesis and solid-state structures of DMAP-coordinated ([L(DMAP)GaPn][OTf]; Pn = Sb 3, Bi 4) and base-free dipnictene dications ([LGaPn][BArF], Pn = Sb: = 24, 5a; 20, 5b; Bi: = 24, 6a; 20, 6b). Quantum chemical calculations indicate that the dications 5 and 6 represent isoelectronic analogues of the butadiene dication.

Snapshots of sequential polyphosphide rearrangement upon metallatetrylene addition.

Insertion and functionalization of gallasilylenes [LSi-Ga(Cl)L] (L = PhC(NBu); L = [{2,6-iPrCHNCMe}CH]) into the -E rings of [Cp*Fe(-E)] (Cp* = -CMe; E = P, As) are reported. Reactions of [Cp*Fe(-E)] with gallasilylene result in E-E/Si-Ga bond cleavage and the insertion of the silylene in the -E rings. [(LSi-Ga(Cl)L){(-P)FeCp*}], in which the Si atom binds to the bent -P ring, was identified as a reaction intermediate.

Deciphering the Structural and Chemical Transformations of Oxide Catalysts during Oxygen Evolution Reaction Using Quick X-ray Absorption Spectroscopy and Machine Learning.

Bimetallic transition-metal oxides, such as spinel-like CoFeO materials, are known as attractive catalysts for the oxygen evolution reaction (OER) in alkaline electrolytes. Nonetheless, unveiling the real active species and active states in these catalysts remains a challenge. The coexistence of metal ions in different chemical states and in different chemical environments, including disordered X-ray amorphous phases that all evolve under reaction conditions, hinders the application of common operando techniques.

Density-Dependence of Surface Transport in Tellurium-Enriched Nanograined Bulk Bi Te.

Three-dimensional topological insulators (3D TI) exhibit conventional parabolic bulk bands and protected Dirac surface states. A thorough investigation of the different transport channels provided by the bulk and surface carriers using macroscopic samples may provide a path toward accessing superior surface transport properties. Bi Te materials make promising 3D TI models; however, due to their complicated defect chemistry, these materials have a high number of charge carriers in the bulk that dominate the transport, even as nanograined structures.

Modulating the frontier orbitals of L(X)Ga-substituted diphosphenes [L(X)GaP] (X = Cl, Br) and their facile oxidation to radical cations.

Modulating the electronic structures of main group element compounds is crucial to control their chemical reactivity. Herein we report on the synthesis, frontier orbital modulation, and one-electron oxidation of two L(X)Ga-substituted diphosphenes [L(X)GaP] (X = Cl 2a, Br 2b; L = HC[C(Me)N(Ar)], Ar = 2,6-PrCH). Photolysis of L(Cl)GaPCO 1 gave [L(Cl)GaP]2a, which reacted with MeSiBr with halide exchange to [L(Br)GaP]2b.

Single-entity Electrochemistry Unveils Dynamic Transformation during Tandem Catalysis of Cu O and Co O for Converting NO to NH.

Electrochemically converting nitrate to ammonia is an essential and sustainable approach to restoring the globally perturbed nitrogen cycle. The rational design of catalysts for the nitrate reduction reaction (NO RR) based on a detailed understanding of the reaction mechanism is of high significance. We report a Cu O+Co O tandem catalyst which enhances the NH production rate by ≈2.