Synthesis and isolation of a triplet bismuthinidene with a quenched magnetic response

Science, Год журнала: 2023, Номер 380(6649), С. 1043 - 1048

Опубликована: Май 18, 2023

Large spin-orbit coupling (SOC) is an intrinsic property of the heavy elements that directly affects electronic structures compounds. In this work, we report synthesis and characterization a monocoordinate bismuthinidene features rigid bulky ligand. All magnetic measurements [superconducting quantum interference device (SQUID), nuclear resonance (NMR)] point to diamagnetic compound. However, multiconfigurational chemical calculations predict ground state compound be dominated (76%) by spin triplet. The apparent diamagnetism explained extremely large SOC-induced positive zero-field splitting more than 4500 wavenumbers leaves M S = 0 sublevel thermally isolated in state.

Язык: Английский

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Activating Bi p‐orbitals in Dispersed Clusters of Amorphous BiO_x for Electrocatalytic Nitrogen Reduction

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(15)

Опубликована: Фев. 13, 2023

Catalytic strategies based on main group metals are significantly less advanced than those of transition metal catalysis, leaving untapped areas potentially fruitful research. We here demonstrate an effective approach for the modulation Bi 6p energy levels during construction atomically dispersed clusters amorphous BiOx . oxidation state is proposed to strongly affects nitrogen fixation activity, with half-occupied pz orbitals Bi2+ ions being highly efficient toward electron injection into inert N2 molecule. With sufficient catalytic sites adsorb and activate , bonding between catalyst able be in situ identified. The shows outstanding Faraday efficiency (≈30 %) high yield (≈113 μg h-1 mg-1cat ) NH3 production, outperforming most existing catalysts aqueous solution. These results lay basis developing potential p-block elements catalysis multi-electron reactions.

Язык: Английский

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Bismuth radical catalysis in the activation and coupling of redox-active electrophiles

Nature Chemistry, Год журнала: 2023, Номер 15(8), С. 1138 - 1145

Опубликована: Июнь 1, 2023

Radical cross-coupling reactions represent a revolutionary tool to make C(sp3)-C and C(sp3)-heteroatom bonds by means of transition metals photoredox or electrochemical approaches. However, the use main-group elements harness this type reactivity has been little explored. Here we show how low-valency bismuth complex is able undergo one-electron oxidative addition with redox-active alkyl-radical precursors, mimicking behaviour first-row metals. This paradigm for gives rise well-defined complexes, which could be fully characterized in solution solid state. The resulting Bi(III)-C(sp3) intermediates display divergent patterns depending on α-substituents alkyl fragment. Mechanistic investigations led development bismuth-catalysed C(sp3)-N reaction that operates under mild conditions accommodates synthetically relevant NH-heterocycles as coupling partners.

Язык: Английский

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Comparative study of visible-light active BiOI and N,Pd-TiO2 photocatalysts: Catalytic ozonation for dye degradation

Colloids and Surfaces A Physicochemical and Engineering Aspects, Год журнала: 2024, Номер 684, С. 133167 - 133167

Опубликована: Янв. 8, 2024

The increasing demand for clean water requires the development of simple, cheap, and efficient catalysts systems pollution remediation. To develop cheap yet hybrid advanced oxidation processes degradation organic pollutants in their systematic comparison under similar conditions to make informed decisions economically feasible sustainable systems. Visible light active single BiOI N, Pd co-doped TiO2 were investigated photocatalytic ozonation (PCO) methylene blue (MB) degradation. Metal non-metal co-doping improved morphology, band structure sites on surface shift its absorption into visible region. MB with PCO N,Pd-TiO2 was practically but showed improvement mineralization efficiency. However, surpassed that due influenced generated free radicals during processes. system progressed through existence involvement strongly oxidizing non-selective hydroxyl towards enhanced dye intermediates while steered by superoxide radical is selective had lower efficiency formed despite high initial efficacy. work demonstrated semiconductors like as potential candidates application real applications matching activities UV TiO2. This advances use based environmental

Язык: Английский

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Red-Light-Active N,C,N-Pincer Bismuthinidene: Excited State Dynamics and Mechanism of Oxidative Addition into Aryl Iodides

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Фев. 10, 2025

Despite the progress made in field of synthetic organic photocatalysis over past decade, use higher wavelengths, especially those deep-red portion electromagnetic spectrum, remains comparatively rare. We have previously disclosed that a well-defined N,C,N-pincer bismuthinidene (1a) can undergo formal oxidative addition into wide range aryl electrophiles upon absorption low-energy red light. In this study, we map out photophysical dynamics 1a and glean insights nature excited state responsible for activation electrophiles. Transient emission techniques reveal that, irradiation with light, complex undergoes direct S0 → S1 metal-to-ligand charge transfer (MLCT) transition, followed by rapid intersystem crossing (ISC) to highly reducing emissive triplet (−2.61 V vs Fc+/0 MeCN). The low dissipative losses incurred during ISC (∼6% incident light energy) help rationalize ability convert useful chemical energy. Spectroelectrochemical computational data support charge-separated excited-state structure radical-anion character on ligand radical-cation bismuth. Kinetic studies competition experiments afford mechanism iodides; concerted inner-sphere processes from are ruled out, strongly supporting pathway proceeds via outer-sphere dissociative electron transfer.

Язык: Английский

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Bi-Catalyzed Trifluoromethylation of C(sp²)–H Bonds under Light

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(47), С. 25538 - 25544

Опубликована: Ноя. 14, 2023

We disclose a Bi-catalyzed C–H trifluoromethylation of (hetero)arenes using CF3SO2Cl under light irradiation. The catalytic method permits the direct functionalization various heterocycles bearing distinct functional groups. structural and computational studies suggest that process occurs through an open-shell redox manifold at bismuth, comprising three unusual elementary steps for main group element. cycle starts with rapid oxidative addition to low-valent Bi(I) catalyst, followed by light-induced homolysis Bi(III)–O bond generate trifluoromethyl radical upon extrusion SO2, is closed hydrogen-atom transfer Bi(II) intermediate.

Язык: Английский

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Bismuth in Radical Chemistry and Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(8)

Опубликована: Ноя. 22, 2023

Abstract Whereas indications of radical reactivity in bismuth compounds can be traced back to the 19 th century, preparation and characterization both transient persistent bismuth‐radical species has only been established recent decades. These advancements led emergence field chemistry, mirroring progress seen for other main‐group elements. The seminal fundamental studies this area have ultimately paved way development catalytic methodologies involving intermediates, a promising approach that remains largely untapped broad landscape synthetic organic chemistry. In review, we delve into milestones eventually present state‐of‐the‐art Our focus aims at outlining intrinsic discoveries inorganic/organometallic chemistry contextualizing their practical applications synthesis catalysis.

Язык: Английский

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Metallomimetic Chemistry of a Cationic, Geometrically Constrained Phosphine in the Catalytic Hydrodefluorination and Amination of Ar–F Bonds

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(6), С. 3786 - 3794

Опубликована: Фев. 4, 2023

The synthesis, isolation, and reactivity of a cationic, geometrically constrained σ3-P compound in the hexaphenyl-carbodiphosphoranyl-based pincer-type ligand (1+) are reported. 1+ reacts with electron-poor fluoroarenes via an oxidative addition-type reaction C-F bond to PIII-center, yielding new fluorophosphorane-type species (PV). This was used catalytic hydrodefluorination Ar-F bonds PhSiH3, C-N bond-forming cross-coupling reactions between aminosilanes. Importantly, these closely mimics mode action transition metal-based catalysts.

Язык: Английский

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Charge Makes a Difference: Molecular Ionic Bismuth Compounds

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(24)

Опубликована: Фев. 27, 2023

Key challenges in modern synthetic chemistry include the design of reliable, selective, and more sustainable methods, as well development promising candidates for new materials. Molecular bismuth compounds offer valuable opportunities they show an intriguing spectrum properties that is yet to be fully exploited: a soft character, rich coordination chemistry, availability broad variety oxidation states (at least +V -I) formal charges +3 -3) at Bi atoms, reversible switching between multiple states. All this paired with status non-precious (semi-)metal good tendency towards low toxicity. Recent findings some these only come into reach, or can substantially optimized, when charged are specifically addressed. In review, essential contributions synthesis, analyses, utilization ionic highlighted.

Язык: Английский

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Plasmon Bi in-situ anchored on BiOCl nanosheets assembled microspheres towards optimized photothermal-photocatalytic performance

Chinese Chemical Letters, Год журнала: 2023, Номер 35(2), С. 108591 - 108591

Опубликована: Май 19, 2023

Язык: Английский

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