Abstract The pivalates RZnOPiv⋅Mg(OPiv)X⋅ n LiCl (OPiv=pivalate; R=aryl; X=Cl, Br, I) stand out amongst salt‐supported organometallic reagents, because apart from their effectiveness in Negishi cross‐coupling reactions, they show more resistance to attack by moist air than conventional compounds. Herein a combination of synthesis, coupling applications, X‐ray crystallographic studies, NMR (including DOSY) and ESI mass spectrometric studies provide details these pivalate reagents own right. A...

Abstract First‐row transition‐metal complexes hold great potential as catalysts for hydrogenations and related reductive reactions. Homo‐ heteroleptic arene/alkene metalates(1−) (M=Co, Fe) are a structurally distinct catalyst class with good activities in of alkenes alkynes. The first syntheses the cobaltates [K([18]crown‐6)][Co(η 4 ‐cod)(η 2 ‐styrene) ] ( 5 ) ‐dct)(η ‐cod)] 6 ), homoleptic complex [K(thf) ][Co(η ‐dct) 7 ; dct=dibenzo[ , e ]cyclooctatetraene, cod=1,5‐cyclooctadiene),...

Redox noninnocent ligands are a promising tool to moderate electron transfer processes within base-metal catalysts. This report introduces bis(imino)acenaphthene (BIAN) cobaltate complexes as hydrogenation Sterically hindered trisubstituted alkenes, imines, and quinolines underwent clean under mild conditions (2–10 bar, 20–80 °C) by use of the stable catalyst precursor [(DippBIAN)CoBr2] cocatalyst LiEt3BH. Mechanistic studies support homogeneous catalysis pathway involving alkene hydrido...

The gas-phase reactions between Ptn+ clusters (n = 1−5) and the inorganic substrates H2, O2, NH3, H2O, CO2, N2O have been investigated using FT-ICR mass spectrometry. It is found that Pt2+ unique in efficiently activating NH3 whereas other simply add this reactant primary reactions. consecutive products Pt4(NH3)3+ Pt5NH3+, however, also induce dehydrogenation of further NH3. Reactions with effect O transfer, those O2 lead to degradation platinum by loss neutral PtO2. Only Pt5+ observed H2...

All that glitters…︁The gas-phase reactions of the bimetallic cluster ions PtmAun+ (m+n≤4) with dioxygen and methane are investigated. The platinum-rich undergo degradation processes dehydrogenation reactions, which also known for pure Ptm+ clusters. In contrast, gold-rich found to be unreactive, similar corresponding Aum+ This distinct trend in reactivity (see graphic) is correlated systems' electronic properties changing as a function composition.

The bimetallic cluster ion PtAu+ activates methane in the gas-phase, yielding carbene PtAuCH2+ which further reacts with ammonia under C−N coupling. In contrast, neither Pt2+ nor Au2+ mediates bond formation. This example demonstrates how activation gas phase can be tuned by cooperative effects clusters.

Fourier transform ion-cyclotron resonance mass spectrometry is used to investigate the reactivity of mass-selected bimetallic PtmAun+ clusters (m + n ≤ 4) with respect C−N coupling methane and ammonia. To this end, reactions heterometallic carbene species PtmAunCH2+ NH3 as well those bare CH3NH2 are studied. On basis these experiments augmented by deuterium labeling studies, structural assignments for reaction products proposed. Surprisingly, only dinuclear PtAuCH2+ mediates bond formation...

Organic iodides bearing a cationic quaternary ammonium group at remote position react with zerovalent Pd complexes, Zn, or In leading to C−I bond insertion. The resulting charge-tagged organometallics can be detected by electrospray-ionization mass spectrometry, which provides detailed information on their stoichiometry, oxidation state, and coordination sphere. properties of the observed organopalladium -zinc intermediates largely agree previous findings, whereas organoindium species show...

We have used a combination of electrospray ionization (ESI) mass spectrometry, electrical conductivity measurements, and NMR spectroscopy to investigate the effect LiCl on solutions organylzinc halides RZnX (R = Bu, Bn, Ph; X halogen) dibutylzinc Bu2Zn in tetrahydrofuran. In case RZnX, addition LiX (X Cl) leads steep rise ESI signal intensities RZnX2– organozincate anions. At same time, conductivities strongly increase absorptions α-H atoms BuZnX shift upfield. These results consistently...

Solutions of allyl indium reagents formed in the reactions with bromide and iodide, respectively, N,N-dimethylformamide, tetrahydrofuran, water were analyzed by a combination electrospray-ionization mass spectrometry, temperature-dependent 1H NMR spectroscopy, electrical conductivity measurements. Additional spectrometric experiments probed charge-tagged derivatives reagents. The results obtained indicate presence indium(+3) species, which undergo heterolytic dissociation to yield ions such...

Tetrahydrofuran solutions of the products formed in LiCl-mediated zinc insertion reactions into various organic halides RHal were analyzed by anion-mode electrospray ionization (ESI) mass spectrometry. In all cases, organozincate anions observed. The with RHal, Hal = Br and I, yielded predominantly mononuclear complexes, such as ZnRHal2− ZnRHalCl−, whereas for reaction benzylchloride abundant polynuclear organozincates, Zn2Bn2Cl3− Zn3Bn3Cl4−, detected. equilibria governing stoichiometry...

Highly charged: Electrospray-ionization mass spectrometry shows that single-stranded oligonucleotide dC12-encapsulated silver nanoclusters contain Ag64+ cores at basic pH values (see section of spectrum). The high positive charge the cluster is presumably essential for preventing multiply deprotonated dC12 ligand from unfolding.

The aerobic dehydrogenative lactonization of alkenoic acids facilitated by a cooperative nonmetallic catalyst pair is reported. title procedure relies on the adjusted interplay photoredox and selenium-π-acid catalyst, which allows for regiocontrolled construction five- six-membered lactone rings in yields up to 96%. Notable features this method are pronounced efficiency practicality, good functional group tolerance, high sustainability, since ambient air visible light adequate clean...

Abstract Pd‐mediated Negishi cross‐coupling reactions were studied by a combination of kinetic measurements, electrospray‐ionization (ESI) mass spectrometry, 31 P NMR and UV/Vis spectroscopy. The measurements point to rate‐determining oxidative addition. Surprisingly, this step seems involve not only the Pd catalyst aryl halide substrate, but also organozinc reagent. In context, ESI‐mass spectrometric observation heterobimetallic Pd–Zn complexes [L 2 PdZnR] + (L=S‐PHOS, R=Bu, Ph, Bn) is...

Grignard reagents RMgCl and their so-called turbo variant, the highly reactive RMgCl⋅LiCl, are of exceptional synthetic utility. Nevertheless, it is still not fully understood which species these compounds form in solution and, particular, way LiCl exerts its reactivity-enhancing effect. A combination electrospray-ionization mass spectrometry, electrical conductivity measurements, NMR spectroscopy (including diffusion-ordered spectroscopy), quantum chemical calculations used to analyze...

Tetraalkylcuprates are prototypical examples of organocopper(III) species, which remained elusive until their recent detection by NMR spectroscopy. In agreement with the studies, present electrospray ionization mass spectrometric experiments, as well supporting electrical conductivity measurements, indicate that LiCuMe(2)·LiCN reacts a series alkyl halides RX. The resulting Li(+)Me(2)CuR(CN)(-) intermediates then afford observable Me(3)CuR(-) tetraalkylcuprate anions upon Me/CN exchanges...

Abstract Palladium ate complexes are frequently invoked as important intermediates in Heck and cross‐coupling reactions, but so far have largely eluded characterization at the molecular level. Here, we use electrospray‐ionization mass spectrometry, electrical conductivity measurements, NMR spectroscopy to show that electron‐poor catalyst [L 3 Pd] (L=tris[3,5‐bis(trifluoromethyl)phenyl]phosphine) readily reacts with Br − ions afford anionic, zero‐valent complex PdBr] . In contrast,...

Molybdenum pentachloride is an unusually powerful reagent for the dehydrogenative coupling of arenes. Owing to high reaction rate using MoCl5, several labile moieties are tolerated in this transformation. The mechanistic course was controversially discussed although indications a single electron transfer as initial step were found recently. Herein, based on combined study including synthetic investigations, electrochemical measurements, EPR spectroscopy, DFT calculations, and mass...

Previous attempts to characterize the internal energies of ions produced by electrospray ionization (ESI) have chiefly relied upon benzylpyridinium ions, R-BnPy+, as thermometer ions. However, these systems are not well suited for this purpose because their relatively high dissociation energies. Here, we propose benzhydrylpyridinium R,R′-BhPy+, a new class DLPNO-CCSD(T)/CBS//PBE0-D3BJ calculations R,R′-BhPy+ (R,R′ = H,H′; Me,Me′; H,OMe′; Me,OMe′; OMe,OMe′; NPh2,NPh2′) predict that fragment...

Although organometallic complexes of the late 3d elements are known to undergo both one‐ and two‐electron reactions, their relative propensities do so remain poorly understood. To gain direct insight into competition between these different pathways, we have analyzed unimolecular gas‐phase reactivity a series well‐defined model [(Me3SiCH2)nM]− (M = Fe, Co, Ni, Cu; n 2 – 4). Applying combination tandem‐mass spectrometry, quantum‐chemical computations, statistical rate theory calculations,...

Although organometallic complexes of the late 3d elements are known to undergo both one‐ and two‐electron reactions, their relative propensities do so remain poorly understood. To gain direct insight into competition between these different pathways, we have analyzed unimolecular gas‐phase reactivity a series well‐defined model [(Me3SiCH2)nM]− (M = Fe, Co, Ni, Cu; n 2 – 4). Applying combination tandem‐mass spectrometry, quantum‐chemical computations, statistical rate theory calculations,...

Transmetalation is a key elementary step in organometallic chemistry, for which reason there keen interest better understanding the factors governing this reaction. We have previously reported unusual transfer of phenyl anion from boron to lithium gas‐phase dissociation [LiBr(tBu)(Ph)Bpin]− (Chem. Eur. J.2024, 43, e202303653). Here, we use combination fragmentation experiments and quantum chemical calculations probe reactivity related adducts [MX(R)(Ph)Bpin]− (R = nBu, tBu, Ph; X Cl, Br, I,...

The gas-phase reactions of the platinum−carbene clusters PtnCH2+ (n = 2−5) with substrates O2, CH4, NH3, and H2O have been investigated by FT-ICR mass spectrometry compared previous results for mononuclear homologue PtCH2+. ion−molecule O2 CH4 are similar to corresponding processes observed In contrast, a surprising difference evolves in NH3 H2O. Whereas PtCH2+ mediates carbon−heteroatom bond formation as an attractive way toward methane functionalization, homologous fail this regard...

Electrospray ionization (ESI) of mixtures organolithium compounds and zinc chloride in tetrahydrofuran produced manifold mono- polynuclear organozincate anions. Formation the latter is strongly favored by incorporation ligands, which apparently adopt bridging binding modes. Analysis LinBu/ZnCl2 solutions at different concentrations showed that relative ESI signal intensities for anions aggregation states closely correlate with their expected equilibria solution. Moreover, uni- bimolecular...