scholarly journals Squeezing Bi: PNP and P2N3 Pincer Complexes of Bismuth(III

2020 ◽  
Author(s):  
Marcus B. Kindervater ◽  
Toren Hynes ◽  
Katherine Marczenko ◽  
Saurabh Chitnis
Keyword(s):  
Structural Dynamics ◽  
Pincer Complexes ◽  
Pincer Ligand ◽  
Bismuth Complex

We report the first application of a rigid <i>P<sub>2</sub>N<sub>3</sub></i> pincer ligand in p-block chemistry by preparing its bismuth complex. We also report the first example of bismuth complexes featuring a flexible <i>PNP</i> pincer ligand, which shows phase-dependent structural dynamics. Highly electrophilic, albeit thermally unstable, Bi(III) complexes of the <i>PNP</i> ligand were also prepared. <br>

Squeezing Bi: PNP and P2N3 Pincer Complexes of Bismuth(III

2020 ◽  
Author(s):  
Marcus B. Kindervater ◽  
Toren Hynes ◽  
Katherine Marczenko ◽  
Saurabh Chitnis
Keyword(s):  
Structural Dynamics ◽  
Pincer Complexes ◽  
Pincer Ligand ◽  
Bismuth Complex

We report the first application of a rigid <i>P<sub>2</sub>N<sub>3</sub></i> pincer ligand in p-block chemistry by preparing its bismuth complex. We also report the first example of bismuth complexes featuring a flexible <i>PNP</i> pincer ligand, which shows phase-dependent structural dynamics. Highly electrophilic, albeit thermally unstable, Bi(III) complexes of the <i>PNP</i> ligand were also prepared. <br>

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

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 CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-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.

scholarly journals Cobalt Pincer Complexes in Catalytic C–H Borylation: The Pincer Ligand Flips Rather Than Dearomatizes

ACS Catalysis ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 10606-10618 ◽  
Author(s):  
Haixia Li ◽  
Jennifer V. Obligacion ◽  
Paul J. Chirik ◽  
Michael B. Hall
Keyword(s):  
Pincer Complexes ◽  
Pincer Ligand

Divergent Reactivity of CO2 and CO and Related Substrates at the Nickel Carbon Double Bond of (PCcarbeneP)Ni(II) Pincer Complexes

2018 ◽  
Author(s):  
Etienne A. LaPierre ◽  
Warren Piers ◽  
Chris Gendy
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Double Bond ◽  
Transfer Reactions ◽  
Pincer Complexes ◽  
Pincer Ligand ◽  
Group Transfer ◽  
Ligand Structure ◽  
Carbon Double Bond

The addition of carbon monoxide (CO), carbon dioxide (CO<sub>2</sub>) and isoelectronic isocyanide and isocyanates to the nickel carbene bond in PC<sub>carbene</sub>P pincer complexes is reported. For CO and CNR, irreversible group transfer reactions are observed, while for CO<sub>2</sub>, a reversible 2+2 addition to the carbene moiety occurs. The course of the CO and CO<sub>2</sub> reactions are strongly affected by the nature of the PC<sub>carbene</sub>P pincer ligand framework and a new more rigid ligand based on a 10,10-dimethyl-9,10-dihydroanthracene core was designed in order to study these reactions, illustrating the profound effect of small changes in ligand structure on reaction outcomes.

N–H cleavage as a route to new pincer complexes of high-valent rhenium

2016 ◽  
Vol 45 (46) ◽  
pp. 18532-18540 ◽  
Author(s):  
Alex J. Kosanovich ◽  
Wei-Chun Shih ◽  
Rodrigo Ramírez-Contreras ◽  
Oleg. V. Ozerov
Keyword(s):  
Pincer Complexes ◽  
Pincer Ligand ◽  
Oxo Complexes ◽  
High Valent ◽  
Rhenium Oxo Complexes

Rhenium oxo complexes of a new PNN (phosphine-amido-amido) pincer ligand display rotameric isomerism and can be reversibly protonated.

scholarly journals Group 11 Pincer Oxazoline Complexes

2021 ◽  
Author(s):  
Mahroo T. Seighalani
Keyword(s):  
Point Group ◽  
Diffraction Method ◽  
Binding Mode ◽  
Group Symmetry ◽  
Pincer Complexes ◽  
Pincer Ligands ◽  
Henry Reaction ◽  
X Ray Diffraction ◽  
Pincer Ligand ◽  
Nitroaldol Reaction

The synthesis and characterization of new copper pincer complexes via cyclometallation of potentially anionic pincer ligands with C1 point group symmetry is reported. All of these complexes have been characterized by single crystal X-ray diffraction method, which confirms the proposed tridentate binding mode of pincer ligand and the formation of an amido N-Cu bond. The reactivity of two of the complexes was investigated towards C-C bond formation reaction, notably the Henry reaction. One of the complexes, which was derived from the achiral pincer ligand, is shown to be a suitable catalyst for the Henry reaction under the standard conditions. The Henry or nitroaldol reaction is one of the organic reactions which affords a C-C bond. The product of this reaction is a β-nitro alcohol which is formed by addition of a nitroalkane to a carbonyl compound.

Divergent Reactivity of CO2 and CO and Related Substrates at the Nickel Carbon Double Bond of (PCcarbeneP)Ni(II) Pincer Complexes

2018 ◽  
Author(s):  
Etienne A. LaPierre ◽  
Warren Piers ◽  
Chris Gendy
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Double Bond ◽  
Transfer Reactions ◽  
Pincer Complexes ◽  
Pincer Ligand ◽  
Group Transfer ◽  
Ligand Structure ◽  
Carbon Double Bond

The addition of carbon monoxide (CO), carbon dioxide (CO<sub>2</sub>) and isoelectronic isocyanide and isocyanates to the nickel carbene bond in PC<sub>carbene</sub>P pincer complexes is reported. For CO and CNR, irreversible group transfer reactions are observed, while for CO<sub>2</sub>, a reversible 2+2 addition to the carbene moiety occurs. The course of the CO and CO<sub>2</sub> reactions are strongly affected by the nature of the PC<sub>carbene</sub>P pincer ligand framework and a new more rigid ligand based on a 10,10-dimethyl-9,10-dihydroanthracene core was designed in order to study these reactions, illustrating the profound effect of small changes in ligand structure on reaction outcomes.

scholarly journals Metal–ligand cooperation by aromatization–dearomatization as a tool in single bond activation

2015 ◽  
Vol 373 (2037) ◽  
pp. 20140189 ◽  
Author(s):  
David Milstein
Keyword(s):  
Bond Activation ◽  
Short Review ◽  
Catalytic Reactions ◽  
Pincer Complexes ◽  
Chemical Bonds ◽  
Single Bond ◽  
Metal Centre ◽  
Pincer Ligand ◽  
Mechanistic Insight ◽  
Metal Ligand

Metal–ligand cooperation (MLC) plays an important role in bond activation processes, enabling many chemical and biological catalytic reactions. A recent new mode of activation of chemical bonds involves ligand aromatization–dearomatization processes in pyridine-based pincer complexes in which chemical bonds are broken reversibly across the metal centre and the pincer-ligand arm, leading to new bond-making and -breaking processes, and new catalysis. In this short review, such processes are briefly exemplified in the activation of C–H, H–H, O–H, N–H and B–H bonds, and mechanistic insight is provided. This new bond activation mode has led to the development of various catalytic reactions, mainly based on alcohols and amines, and to a stepwise approach to thermal H 2 and light-induced O 2 liberation from water.

scholarly journals Palladium(ii) pincer complexes of a C,C,C-NHC, diphosphonium bis(ylide) ligand

2019 ◽  
Vol 48 (5) ◽  
pp. 1709-1721 ◽  
Author(s):  
Rachid Taakili ◽  
Christine Lepetit ◽  
Carine Duhayon ◽  
Dmitry A. Valyaev ◽  
Noël Lugan ◽  
...  
Keyword(s):  
Pincer Complexes ◽  
Pincer Ligand

The preparation, characterization, and reactivity of Pd(ii) complexes of the C,C,C-NHC, diphosphonium bis(ylide) pincer ligand of LX2-type are here described.

scholarly journals Synthesis & Xray structures of Rare Pentacoordinate Pincer Complexes of Ni(II)

2014 ◽  
Vol 70 (a1) ◽  
pp. C916-C916
Author(s):  
Berline Mougang-Soume ◽  
Davit Zargarian
Keyword(s):  
Organometallic Chemistry ◽  
Materials Science ◽  
Catalytic Reactions ◽  
Pincer Complexes ◽  
Substrate Uptake ◽  
Major Focus ◽  
Pincer Ligand ◽  
The Past ◽  
Coordination Site

Pincer complexes have been a major focus in organometallic chemistry over the past four decades due to their important potential in catalysis and materials science. In the case of pincer complexes of d8 metals, a growing number of charge-neutral and cationic derivatives featuring hydrides, alkyls, and other reactive moieties have been shown to catalyze important transformations. Regarding the mechanisms of these catalytic reactions, an important issue that remains unresolved concerns the type of intermediates formed upon substrate uptake, namely: A: Do substrates displace one or more hemi-labile donor moieties of the pincer ligand? Or B: Does the substrate occupy a fifth coordination site while the pincer ligand remains intact (Scheme 1)? In this presentation, Xray crystallography is used to describe the influence of the substitue on the 18-electron species based on POCN-Ni precursors. These new diamagnetic complexes are proposed as models for the intermediates that might be involved in catalytic reactions promoted by this family of complexes (Scheme 2).

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