Search

Numerous synthetic models of the FeMo‐co cluster of nitrogenases have been proposed to find the simplest structure with relevant reactivity. Indeed, such structures are able to perform multi‐electrons reduction processes, such as the conversion of N2 to ammonia, and of CO2 into methane and alkenes. The most challenging parameter to imitate is indeed the central carbide ligand, which is believed to maintain the integrity of iron sulfide assembly during the course of catalytic cycles. The study proposes the use of bis(diphenylthiophosphinoyl)methanediide (SCS)2− as an ideal platform for the synthesis of bi‐ and tetra‐metallic iron complexes, in which the iron‐carbon interaction is maintained upon structural diversification and redox state changes. [ABSTRACT FROM AUTHOR]

A DFT study of several L→Al(ORF)3 (L=Lewis bases) adducts allowed the identification of (iPr2S)→Al(ORF)3 1-SiPr2 as a "stable yet reactive" adduct. 1-SiPr2 was shown to act as a masked Lewis superacid able to release Al(ORF)3 under mild conditions. It could be used to abstract a ORF- ligand from bipyMe2)Ni(ORF)2 (bipyMe2 : 6,6'-dimethyl-2,2'-dipyridyl) and generate the nickel alkoxide complex [(bipyMe2)Ni-(ORF)(iPr2S)]+[(RFO)3Al--F--Al(ORF)3]- 5. Ligand exchange of iPr2S by Ph3P yielded [(bipyMe2)Ni(ORF)(PPh3)]+[(RFO)3Al--F--Al-(ORF)3]-6. [ABSTRACT FROM AUTHOR]

Two different dinitrogen‐derived molybdenum nitrido complexes varying by their geometry, ligand spheres and oxidations states were shown to engage their N ligand in dative bonding with the strong Lewis acid B(C6F5)3. The stable adducts were assessed for frustrated Lewis pair‐type heterolytic E−H bond splitting of hydrosilanes (E=Si) and HB(C6F5)2. Whereas Si−H bond activation was achieved, HB(C6F5)2 was shown to substitute B(C6F5)3 in a quantitative or equilibrated fashion, depending on the nature of the nitrido complex. No B−H bond splitting was observed. Thermodynamics of these reactions, computed by DFT, are in agreement with the experimental outcomes. [ABSTRACT FROM AUTHOR]

Herein, we present a detailed study of the conversion of a nickel(II) diamide precursor to size-tunable, monodisperse nickel nanoparticles (NPs). The thermal decomposition of nickel(II) dioleylamide, synthesized either independently or in situ, resulted in the formation of Ni NPs without the coproduction of water. Mechanistic studies were conducted on the stability and reduction pathway of the NiII precursor, and on the consequent particle formation. Variations in the ratio of trioctylphosine (TOP) to nickel allowed size tunability, which resulted in nanoparticles that ranged in size from 4 to 11 nm in diameter. The DFT calculations support a mechanistic pathway that involves nickel reduction by imine formation. This water-free method was extended to the synthesis of water-sensitive M0 NPs (M=Fe, Co). [ABSTRACT FROM AUTHOR]

The widely used preparation of Ni0 nanoparticles from [Ni(acac)2] (acac=acetylacetonate) and oleylamine, often considered to be a thermolysis or a radical reaction, was analyzed anew by using a combination of DFT modeling and designed mechanistic experiments. Firstly, the reaction was followed up by using TGA to evaluate the energy barrier of the limiting step. Secondly, all the byproducts were identified using NMR spectroscopy, mass spectrometry, FTIR, and X-ray crystallography. These methods allowed us to depict both main and side-reaction pathways. Lastly, DFT modeling was utilized to assess the validity of this new scheme by identifying the limiting steps and evaluating the corresponding energy barriers. The oleylamine was shown to reduce the [Ni(acac)2] complex not through a one-electron radical mechanism, as often stated, but as an hydride donor through a two-electron chemical reduction route. This finding has strong consequences not only for the design of further nanoparticles syntheses that use long-chain amine as a reactant, but also for advanced understanding of catalytic reactions for which these nanoparticles can be employed. [ABSTRACT FROM AUTHOR]

Keywords: AgIII chemistry; cross-coupling; fluorine; high-valent species; trifluoromethylation EN AgIII chemistry cross-coupling fluorine high-valent species trifluoromethylation 15273 15273 1 11/09/21 20211105 NES 211105 B Landing to explore beneath the silvery reflection b of the moon, the unusual air oxidation of silver was investigated, granting access to the homoleptic anion [Ag SP III sp (CF SB 3 sb ) SB 4 sb ] SP - sp ( B 1 b ). The crew compartment of the Lunar Lander illustrates the structure of B 1 b mimicking the heraldic Occitan Cross, symbol of Occitania, where this work was developed. Upon addition of aryl boron derivatives and base, [(phen)Ag SP III sp (CF SB 3 sb ) SB 3 sb ] undergoes aromatic trifluoromethylation. [Extracted from the article]

The widely used preparation of Ni0 nanoparticles from [Ni(acac)2] (acac=acetylacetonate) and oleylamine, often considered to be a thermolysis or a radical reaction, was analyzed anew by using a combination of DFT modeling and designed mechanistic experiments. Firstly, the reaction was followed up by using TGA to evaluate the energy barrier of the limiting step. Secondly, all the byproducts were identified using NMR spectroscopy, mass spectrometry, FTIR, and X-ray crystallography. These methods allowed us to depict both main and side-reaction pathways. Lastly, DFT modeling was utilized to assess the validity of this new scheme by identifying the limiting steps and evaluating the corresponding energy barriers. The oleylamine was shown to reduce the [Ni(acac)2] complex not through a one-electron radical mechanism, as often stated, but as an hydride donor through a two-electron chemical reduction route. This finding has strong consequences not only for the design of further nanoparticles syntheses that use long-chain amine as a reactant, but also for advanced understanding of catalytic reactions for which these nanoparticles can be employed. [ABSTRACT FROM AUTHOR]