scholarly journals DFT calculations bring insight to internal alkyne-to-vinylidene transformations at rhodium PNP- and PONOP-pincer complexes

RSC Advances ◽  
2021 ◽  
Vol 11 (20) ◽  
pp. 11793-11803
Author(s):  
Nasir A. Rajabi ◽  
Claire L. McMullin
Keyword(s):  
Dft Calculations ◽  
Pincer Complexes ◽  
Pincer Ligand ◽  
Bite Angle ◽  
Internal Alkyne

Through DFT calculations, the equilibrium between Rh–alkyne and Rh–vinylidene species of PXNXP pincer ligated Rh cationic complexes is shown to be tuned by the P–Rh–P bite angle, which in turn is dictated by the nature of the X moiety of the pincer ligand.

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

Manganese PNP-pincer catalyzed isomerization of allylic/homo-allylic alcohols to ketones – activity, selectivity, efficiency

2019 ◽  
Vol 9 (22) ◽  
pp. 6327-6334 ◽  
Author(s):  
Tian Xia ◽  
Brian Spiegelberg ◽  
Zhihong Wei ◽  
Haijun Jiao ◽  
Sergey Tin ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Pincer Complexes ◽  
Allylic Alcohols ◽  
Deuterium Labelling ◽  
Reaction Proceeds

Manganese PNP pincer complexes are excellent catalysts for the isomerization of allylic alcohols to the ketones. The reaction proceeds via a dehydrogenation/hydrogenation mechanism as shown by DFT calculations and deuterium labelling.

scholarly journals Estimation of Bite Angle Effect on the Electronic Structure of Cobalt-Phosphine Complexes: A QTAIM Study

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Tamara Papp ◽  
László Kollár ◽  
Tamás Kégl
Keyword(s):  
Electronic Structure ◽  
Simple Model ◽  
Dft Calculations ◽  
Model Compound ◽  
Carbonyl Ligand ◽  
Reaction Conditions ◽  
Phosphine Complexes ◽  
Bite Angle ◽  
Angle Effect ◽  
Donor Character

The influence of bite angle in bisphosphine complexes has been modeled by DFT calculations employing the simple model compound HCo(CO)(PP) (PP = Xantphos or two monophosphine ligands). The increase of the bite angle increases the strength of the H–Co bond, whereas the C–O bond in the carbonyl ligand is weakened revealing an increase also in the donor character. The model compound cis-[HCo(CO)(PPh3)2] shows a flexibility both in terms of energy, and in terms of electronic structure upon the change of the P-Co-P angle, which can be a sign of the flexibility of PPh3 ligands in real reaction conditions.

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.

A Bis-Sulfonyl O,C,O Aryl Pincer Ligand and its Tin(II) Complex: Synthesis, Structural Studies, and DFT Calculations

2014 ◽  
Vol 54 (3) ◽  
pp. 805-808 ◽  
Author(s):  
Mohammad El Ezzi ◽  
Romaric Lenk ◽  
David Madec ◽  
Jean-Marc Sotiropoulos ◽  
Sonia Mallet-Ladeira ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Structural Studies ◽  
Pincer Ligand

Syntheses, X-ray Structures, Photochemistry, Redox Properties, and DFT Calculations of Interconvertiblefac- andmer-[Mn(SPS)(CO)3] Isomers Containing a Flexible SPS-Based Pincer Ligand†

2005 ◽  
Vol 44 (25) ◽  
pp. 9213-9224 ◽  
Author(s):  
Marjolaine Doux ◽  
Nicolas Mézailles ◽  
Louis Ricard ◽  
Pascal Le Floch ◽  
Pedro D. Vaz ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Redox Properties ◽  
Pincer Ligand ◽  
X Ray

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.

scholarly journals Asymmetric Bis-PNP Pincer Complexes of Zirconium and Hafnium - a Measure of Hemilability

2020 ◽  
Author(s):  
Celia Idelson ◽  
Leah Webster ◽  
Tobias Krämer ◽  
Mark Chadwick
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Pincer Complexes ◽  
Pincer Ligands ◽  
Direct Contrast ◽  
Vt Nmr

Asymmetrically-bound pyrrollide-based bis-PNP pincer complexes of zirconium and hafnium<br>have been formed. The [κ2-PNPPh][κ3-PNPPh]MCl2 species are in direct contrast to previous<br>zirconium PNP pincer complexes. The pincer ligands are fluxional in their binding and the<br>energy barrier for exchange has been approximated using VT-NMR spectroscopy and the<br>result validated by DFT calculations.

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