Lewis acid–base interactions between platinum(ii) diaryl complexes and bis(perfluorophenyl)zinc: strongly accelerated reductive elimination induced by a Z-type ligand

2016 ◽  
Vol 52 (43) ◽  
pp. 7039-7042 ◽  
Author(s):  
Allegra L. Liberman-Martin ◽  
Daniel S. Levine ◽  
Micah S. Ziegler ◽  
Robert G. Bergman ◽  
T. Don Tilley

Z-type interactions between bis(perfluorophenyl)zinc and platinum(ii) diaryl complexes supported by 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), and bis(dimethylphosphino)ethane (dmpe) ligands are reported.

2017 ◽  
Vol 114 (46) ◽  
pp. E9775-E9782 ◽  
Author(s):  
Shengda Ding ◽  
Pokhraj Ghosh ◽  
Marcetta Y. Darensbourg ◽  
Michael B. Hall

The hydrogen evolution reaction, as catalyzed by two electrocatalysts [M(N2S2)·Fe(NO)2]+, [Fe-Fe]+ (M = Fe(NO)) and [Ni-Fe]+ (M = Ni) was investigated by computational chemistry. As nominal models of hydrogenase active sites, these bimetallics feature two kinds of actor ligands: Hemilabile, MN2S2 ligands and redox-active, nitrosyl ligands, whose interplay guides the H2 production mechanism. The requisite base and metal open site are masked in the resting state but revealed within the catalytic cycle by cleavage of the MS–Fe(NO)2 bond from the hemilabile metallodithiolate ligand. Introducing two electrons and two protons to [Ni-Fe]+ produces H2 from coupling a hydride temporarily stored on Fe(NO)2 (Lewis acid) and a proton accommodated on the exposed sulfur of the MN2S2 thiolate (Lewis base). This Lewis acid–base pair is initiated and preserved by disrupting the dative donation through protonation on the thiolate or reduction on the thiolate-bound metal. Either manipulation modulates the electron density of the pair to prevent it from reestablishing the dative bond. The electron-buffering nitrosyl’s role is subtler as a bifunctional electron reservoir. With more nitrosyls as in [Fe-Fe]+, accumulated electronic space in the nitrosyls’ π*-orbitals makes reductions easier, but redirects the protonation and reduction to sites that postpone the actuation of the hemilability. Additionally, two electrons donated from two nitrosyl-buffered irons, along with two external electrons, reduce two protons into two hydrides, from which reductive elimination generates H2.


1980 ◽  
Vol 45 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Adéla Kotočová ◽  
Ulrich Mayer

The solvation effect of a number of nonaqueous polar solvents was studied on the oxidation-reduction properties of the [Co(en)3]3+-[Co(en)3]2+ system. Interactions of these ions with the solvent molecules are discussed in terms of their coordination, which is accompanied by a specific interaction of the Lewis acid-base type, namely formation of a hydrogen bond between the interacting particles. This is the main controlling factor of the redox properties of the studied system.


2021 ◽  
Vol 60 (6) ◽  
pp. 3893-3901
Author(s):  
Douglas Turnbull ◽  
Praveen Chaudhary ◽  
Paul Hazendonk ◽  
Stacey D. Wetmore ◽  
Michael Gerken
Keyword(s):  

2021 ◽  
Vol 27 (1) ◽  
pp. 17-23
Author(s):  
Guniganti Balakishan ◽  
Gullapalli Kumaraswamy ◽  
Vykunthapu Narayanarao ◽  
Pagilla Shankaraiah

Abstract A Cu(II)-catalyzed Csp2-Se and Csp2-Sulfur bond formation was achieved with moderate to good yields without the aid of Lewis acid and base. The reaction is compatible with a wide range of heterocycles such as benzothiazole, thiazole, and imidazole. Also, this typical protocol is found to be active in thio-selenation via S-H activation. Additionally, we proposed a plausible mechanistic pathway involving Cu(III) putative intermediate.


Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...


Author(s):  
Shan Peng ◽  
Zhongqiu Chen ◽  
Qing Huang ◽  
Xiaohong Xia ◽  
Zhuo Wang ◽  
...  

2020 ◽  
Author(s):  
Xian-Ming Zhang ◽  
Ying-Xia Wang ◽  
Hui-Min Wang ◽  
Pan Meng ◽  
Dong-Xia Song ◽  
...  

The design and utilization of dual sites for synergistic catalysts has been recognised as an efficient method towards high-efficiency catalysis in the cyanosilylation of aldehydes, which gives the key intermediates...


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