B−C Bond Cleavage of BArFAnion Upon Oxidation of Rhodium(I) with AgBArF. Phosphinite Rhodium(I), Rhodium(II), and Rhodium(III) Pincer Complexes

Hiyam Salem; Linda J. W. Shimon; Gregory Leitus; Lev Weiner; David Milstein

doi:10.1021/om800034t

B–H Bond Cleavage via Metal–Ligand Cooperation by Dearomatized Ruthenium Pincer Complexes

Organometallics ◽

10.1021/om500311a ◽

2014 ◽

Vol 33 (14) ◽

pp. 3716-3726 ◽

Cited By ~ 42

Author(s):

Aviel Anaby ◽

Burkhard Butschke ◽

Yehoshoa Ben-David ◽

Linda J. W. Shimon ◽

Gregory Leitus ◽

...

Keyword(s):

Bond Cleavage ◽

Pincer Complexes ◽

Metal Ligand

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C−N, C−S and S−S Bond Cleavage by Rhodium PC carbene P Pincer Complexes

Chemistry - An Asian Journal ◽

10.1002/asia.202000515 ◽

2020 ◽

Vol 15 (18) ◽

pp. 2873-2878

Author(s):

Hendrik Tinnermann ◽

Rowan D. Young

Keyword(s):

Bond Cleavage ◽

Pincer Complexes

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Osmium-Mediated CH and CC Bond Cleavage of a Phenolic Substrate:p-Quinone Methide and Methylene Arenium Pincer Complexes

Chemistry - A European Journal ◽

10.1002/chem.200601385 ◽

2007 ◽

Vol 13 (5) ◽

pp. 1382-1393 ◽

Cited By ~ 22

Author(s):

Régis M. Gauvin ◽

Haim Rozenberg ◽

Linda J. W. Shimon ◽

Yehoshoa Ben-David ◽

David Milstein

Keyword(s):

Bond Cleavage ◽

Quinone Methide ◽

Pincer Complexes

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Arene C–H Bond Coordination versus C–H Bond Cleavage in Low-Valent Group 6 Carbonyl Pincer Complexes

Organometallics ◽

10.1021/acs.organomet.6b00563 ◽

2016 ◽

Vol 35 (17) ◽

pp. 3032-3039 ◽

Cited By ~ 9

Author(s):

Sara R. M. M. de Aguiar ◽

Berthold Stöger ◽

Ernst Pittenauer ◽

Günter Allmaier ◽

Luis F. Veiros ◽

...

Keyword(s):

Bond Cleavage ◽

Pincer Complexes ◽

Group 6 ◽

Low Valent

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Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

10.26434/chemrxiv.11742687 ◽

2020 ◽

Author(s):

Shubham Deolka ◽

Orestes Rivada Wheelaghan ◽

Sandra Aristizábal ◽

Robert Fayzullin ◽

Shrinwantu Pal ◽

...

Keyword(s):

Alkyl Group ◽

Bond Activation ◽

Bond Cleavage ◽

Terminal Alkyne ◽

Alkyl Aryl ◽

Metal Metal ◽

The Stability ◽

Selective Formation ◽

Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

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Room Temperature Alkali Metal Reduction of Carbon Dioxide

10.26434/chemrxiv.12665336 ◽

2020 ◽

Author(s):

Lucas A. Freeman ◽

Akachukwu D. Obi ◽

Haleigh R. Machost ◽

Andrew Molino ◽

Asa W. Nichols ◽

...

Keyword(s):

Alkali Metal ◽

Alkali Metals ◽

Room Temperature ◽

Chemical Reduction ◽

Bond Cleavage ◽

Open Shell ◽

Metal Reduction ◽

One Pot ◽

Earth Abundant ◽

Electron Reduction

The reduction of the relatively inert carbon–oxygen bonds of CO2 to access useful CO2-derived organic products is one of the most important fundamental challenges in synthetic chemistry. Facilitating this bond-cleavage using earth-abundant, non-toxic main group elements (MGEs) is especially arduous because of the difficulty in achieving strong inner-sphere interactions between CO2 and the MGE. Herein we report the first successful chemical reduction of CO2 at room temperature by alkali metals, promoted by a cyclic(alkyl)(amino) carbene (CAAC). One-electron reduction of CAAC-CO2 adduct (1) with lithium, sodium or potassium metal yields stable monoanionic radicals clusters [M(CAAC–CO2)]n(M = Li, Na, K, 2-4) and two-electron alkali metal reduction affords open-shell, dianionic clusters of the general formula [M2(CAAC–CO2)]n (5-8). It is notable that these crystalline clusters of reduced CO2 may also be isolated via the “one-pot” reaction of free CO2 with free CAAC followed by the addition of alkali metals – a reductive process which does not occur in the absence of carbene. Each of the products 2-8 were investigated using a combination of experimental and theoretical methods.

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Oxygen-Oxygen Bond Cleavage and Formation in Co(II) Mediated Stoichiometric O2 Reduction via the Potential Intermediacy of a Co(IV) Oxyl Radical

10.26434/chemrxiv.7176392 ◽

2018 ◽

Author(s):

Lucie Nurdin ◽

Denis M. Spasyuk ◽

Laura Fairburn ◽

Warren Piers ◽

Laurent Maron

Keyword(s):

Bond Cleavage ◽

Peroxo Complex ◽

Oxygen Oxygen ◽

O2 Reduction ◽

Oxygen Bond ◽

Pentadentate Ligand

Diprotonation of a remarkably stable, toluene soluble cobalt peroxo complex supported by a neutral, dianionic pentadentate ligand leads to facile O-O bond cleavage and production of a highly reactive Co(IV) oxyl cation intermediate that dimerizes and releases O2. These processes are relevant to both O2 reduction and O2 evolution and the mechanism was probed in detail both experimentally and computationally.

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Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

10.26434/chemrxiv.5851701 ◽

2018 ◽

Author(s):

Tasneem Siddiquee ◽

Abdul Goni

Keyword(s):

Metal Salts ◽

Molar Ratio ◽

Pincer Complexes ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Pincer Ligand ◽

Tetrahedral Geometry ◽

X Ray ◽

Distorted Tetrahedral Geometry ◽

Cobalt Center

Chemical treatment of CoX2. 6H2O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-tert-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

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Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

10.26434/chemrxiv.7763657.v1 ◽

2019 ◽

Author(s):

Katsutoshi Sato ◽

Shin-ichiro Miyahara ◽

Yuta Ogura ◽

Kotoko Tsujimaru ◽

Yuichiro Wada ◽

...

Keyword(s):

Ammonia Synthesis ◽

Bond Cleavage ◽

Synthesis Process ◽

Strong Electron ◽

Mild Conditions ◽

Ru Nanoparticles ◽

Rate Determining Step ◽

Highly Active ◽

Composite Oxides ◽

Low Crystalline

To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeOx pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba2+, Ce3+ and La3+, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.

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Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

10.26434/chemrxiv.7763657 ◽

2019 ◽

Author(s):

Katsutoshi Sato ◽

Shin-ichiro Miyahara ◽

Yuta Ogura ◽

Kotoko Tsujimaru ◽

Yuichiro Wada ◽

...

Keyword(s):

Ammonia Synthesis ◽

Bond Cleavage ◽

Synthesis Process ◽

Strong Electron ◽

Mild Conditions ◽

Ru Nanoparticles ◽

Rate Determining Step ◽

Highly Active ◽

Composite Oxides ◽

Low Crystalline

To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeOx pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba2+, Ce3+ and La3+, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.

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