Catalytic Formation of Ammonia from Molecular Dinitrogen by Use of Dinitrogen-Bridged Dimolybdenum–Dinitrogen Complexes Bearing PNP-Pincer Ligands: Remarkable Effect of Substituent at PNP-Pincer Ligand

2014 ◽  
Vol 136 (27) ◽  
pp. 9719-9731 ◽  
Author(s):  
Shogo Kuriyama ◽  
Kazuya Arashiba ◽  
Kazunari Nakajima ◽  
Hiromasa Tanaka ◽  
Nobuaki Kamaru ◽  
...  
Keyword(s):  
Pincer Ligands ◽  
Pincer Ligand ◽  
Remarkable Effect ◽  
Dinitrogen Complexes

scholarly journals Ammonia Formation Catalyzed by Dinitrogen-Bridged Dirhenium Complex Bearing PNP-Pincer Ligands under Mild Reaction Conditions

2020 ◽  
Author(s):  
Fanqiang Meng ◽  
Shogo Kuriyama ◽  
Hiromasa Tanaka ◽  
Akihito Egi ◽  
Kazunari Yoshizawa ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Pincer Ligands ◽  
Pincer Ligand ◽  
Reaction Conditions ◽  
Rhenium Atom ◽  
Phosphine Complexes ◽  
Proton Source ◽  
Dinitrogen Complexes ◽  
Dinitrogen Complex ◽  
Ammonia Formation

A series of rhenium complexes bearing a pyridine-based PNP-type pincer ligand are synthesized from rhenium phosphine complexes as precursors. A dinitrogen-bridged dirhenium complex bearing the PNP-type pincer ligands catalytically converts dinitrogen into ammonia in the reaction with KC<sub>8</sub> as a reductant and [HPCy<sub>3</sub>]BAr<sup>F</sup><sub>4</sub> (Cy = cyclohexyl, Ar<sup>F</sup> = 3,5-(CF<sub>3</sub>)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) as a proton source at –78 °C to afford 8.4 equiv of ammonia based on the rhenium atom of the catalyst. The rhenium-dinitrogen complex also catalyzes silylation of dinitrogen in the reaction with KC<sub>8</sub> as a reductant and Me<sub>3</sub>SiCl as a silylating reagent under ambient reaction conditions to afford 11.3 equiv of tris(trimethylsilyl)amine based on the rhenium atom of the catalyst. These results demonstrate the first successful example of catalytic nitrogen fixation under mild reaction conditions by using rhenium-dinitrogen complexes as catalysts.

scholarly journals Ammonia Formation Catalyzed by Dinitrogen-Bridged Dirhenium Complex Bearing PNP-Pincer Ligands under Mild Reaction Conditions

2020 ◽  
Author(s):  
Fanqiang Meng ◽  
Shogo Kuriyama ◽  
Hiromasa Tanaka ◽  
Akihito Egi ◽  
Kazunari Yoshizawa ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Pincer Ligands ◽  
Pincer Ligand ◽  
Reaction Conditions ◽  
Rhenium Atom ◽  
Phosphine Complexes ◽  
Proton Source ◽  
Dinitrogen Complexes ◽  
Dinitrogen Complex ◽  
Ammonia Formation

A series of rhenium complexes bearing a pyridine-based PNP-type pincer ligand are synthesized from rhenium phosphine complexes as precursors. A dinitrogen-bridged dirhenium complex bearing the PNP-type pincer ligands catalytically converts dinitrogen into ammonia in the reaction with KC<sub>8</sub> as a reductant and [HPCy<sub>3</sub>]BAr<sup>F</sup><sub>4</sub> (Cy = cyclohexyl, Ar<sup>F</sup> = 3,5-(CF<sub>3</sub>)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) as a proton source at –78 °C to afford 8.4 equiv of ammonia based on the rhenium atom of the catalyst. The rhenium-dinitrogen complex also catalyzes silylation of dinitrogen in the reaction with KC<sub>8</sub> as a reductant and Me<sub>3</sub>SiCl as a silylating reagent under ambient reaction conditions to afford 11.3 equiv of tris(trimethylsilyl)amine based on the rhenium atom of the catalyst. These results demonstrate the first successful example of catalytic nitrogen fixation under mild reaction conditions by using rhenium-dinitrogen complexes as catalysts.

scholarly journals Iron Complexes of a Proton-Responsive SCS Pincer Ligand with Sensitive Electronic Structure

2021 ◽  
Author(s):  
Kazimer Skubi ◽  
Reagan Hooper ◽  
Brandon Mercado ◽  
Melissa Bollmeyer ◽  
Samantha MacMillan ◽  
...  
Keyword(s):  
Strong Field ◽  
Alkali Metal Cation ◽  
Weak Field ◽  
Pincer Ligands ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Pincer Ligand ◽  
Intermediate Spin ◽  
X Ray Absorption ◽  
Phosphine Complex

SCS pincer ligands have an interesting combination of strong-field and weak-field donors that is also present in the nitrogenase active site. Here, we explore the electronic structures of iron(II) and iron(III) complexes with such a pincer ligand, bearing a monodentate phosphine, thiolate S donor, amide N donor, ammonia, or CO. The ligand scaffold features a protonresponsive thioamide site, and the protonation state of the ligand greatly influences the reduction potential of iron in the phosphine complex. The N–H bond dissociation free energy can be quantitated as 56 ± 2 kcal/mol. EPR spectroscopy and SQUID magnetometry measurements show that the iron(III) complexes with S and N as the fourth donors have an intermediate spin (S = 3/2) ground state with large zero field splitting, and X-ray absorption spectra show high Fe–S covalency. The Mössbauer spectrum changes drastically with the position of a nearby alkali metal cation in the iron(III) amido complex, and DFT calculations explain this phenomenon through a change between having the doubly-occupied orbital as dz2 or dyz, as the former is more influenced by the nearby positive charge.

Synthesis and Reactivity of Iron- and Cobalt-Dinitrogen Complexes Bearing PSiP-Type Pincer Ligands toward Nitrogen Fixation

2017 ◽  
Vol 2017 (32) ◽  
pp. 3769-3778 ◽  
Author(s):  
Ryuji Imayoshi ◽  
Kazunari Nakajima ◽  
Jun Takaya ◽  
Nobuharu Iwasawa ◽  
Yoshiaki Nishibayashi
Keyword(s):  
Nitrogen Fixation ◽  
Pincer Ligands ◽  
Dinitrogen Complexes

Synthesis and reactivity of titanium- and zirconium-dinitrogen complexes bearing anionic pyrrole-based PNP-type pincer ligands

2018 ◽  
Vol 47 (33) ◽  
pp. 11322-11326 ◽  
Author(s):  
Yoshiya Sekiguchi ◽  
Fanqiang Meng ◽  
Hiromasa Tanaka ◽  
Aya Eizawa ◽  
Kazuya Arashiba ◽  
...  
Keyword(s):  
Pincer Ligands ◽  
X Ray ◽  
Dinitrogen Complexes

Dinitrogen-bridged dititanium and dizirconium complexes bearing anionic pyrrole-based PNP-type pincer ligands are prepared and characterized by X-ray analysis.

scholarly journals Monomeric alkoxide and alkylcarbonate complexes of nickel and palladium stabilized with the iPrPCP pincer ligand: a model for the catalytic carboxylation of alcohols to alkyl carbonates

2019 ◽  
Vol 48 (4) ◽  
pp. 1351-1366 ◽  
Author(s):  
Luis M. Martínez-Prieto ◽  
Pilar Palma ◽  
Juan Cámpora
Keyword(s):  
Catalytic Synthesis ◽  
Pincer Ligands ◽  
Pincer Ligand ◽  
Organic Carbonates ◽  
Key Steps

Monomeric nickel and palladium alkoxides stabilized with pincer ligands provide a model for the study of key steps in the catalytic synthesis of organic carbonates from alcohols and CO2.

Synthesis and Protonation of Molybdenum– and Tungsten–Dinitrogen Complexes Bearing PNP-Type Pincer Ligands

2012 ◽  
Vol 31 (5) ◽  
pp. 2035-2041 ◽  
Author(s):  
Kazuya Arashiba ◽  
Kouitsu Sasaki ◽  
Shogo Kuriyama ◽  
Yoshihiro Miyake ◽  
Haruyuki Nakanishi ◽  
...  
Keyword(s):  
Pincer Ligands ◽  
Dinitrogen Complexes ◽  
And Tungsten

Synthesis and Catalytic Activity of Molybdenum–Dinitrogen Complexes Bearing Unsymmetric PNP-Type Pincer Ligands

2012 ◽  
Vol 31 (23) ◽  
pp. 8437-8443 ◽  
Author(s):  
Eriko Kinoshita ◽  
Kazuya Arashiba ◽  
Shogo Kuriyama ◽  
Yoshihiro Miyake ◽  
Ryuji Shimazaki ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Pincer Ligands ◽  
Dinitrogen Complexes

scholarly journals Synthesis and Reactivity of Iron- and Cobalt-Dinitrogen Complexes Bearing PSiP-Type Pincer Ligands toward Nitrogen Fixation

2017 ◽  
Vol 2017 (32) ◽  
pp. 3768-3768 ◽  
Author(s):  
Ryuji Imayoshi ◽  
Kazunari Nakajima ◽  
Jun Takaya ◽  
Nobuharu Iwasawa ◽  
Yoshiaki Nishibayashi
Keyword(s):  
Nitrogen Fixation ◽  
Pincer Ligands ◽  
Dinitrogen Complexes

scholarly journals Innentitelbild: Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands (Angew. Chem. 46/2016)

2016 ◽  
Vol 128 (46) ◽  
pp. 14388-14388
Author(s):  
Shogo Kuriyama ◽  
Kazuya Arashiba ◽  
Hiromasa Tanaka ◽  
Yuki Matsuo ◽  
Kazunari Nakajima ◽  
...  
Keyword(s):  
Pincer Ligands ◽  
Direct Transformation ◽  
Dinitrogen Complexes
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