Square-Planar Cobalt Complexes with Monodentate N-Heterocyclic Carbene Ligation: Synthesis, Structure, and Catalytic Application

2011 ◽  
Vol 30 (17) ◽  
pp. 4687-4694 ◽  
Author(s):  
Zhenbo Mo ◽  
Yuxue Li ◽  
Hung Kay Lee ◽  
Liang Deng
Keyword(s):  
Cobalt Complexes ◽  
Catalytic Application ◽  
Square Planar

Dinuclear cobalt complexes supported by biphenol and binaphthol-derived bis(salicylaldimine) ligands: synthesis, characterization and catalytic application in β-enaminone synthesis from 1,3-dicarbonyl compounds and aliphatic amines

2020 ◽  
Vol 44 (35) ◽  
pp. 15109-15121
Author(s):  
Adelew Estifanos Filkale ◽  
Chandni Pathak
Keyword(s):  
Cobalt Complexes ◽  
Aliphatic Amines ◽  
Ambient Conditions ◽  
Dicarbonyl Compounds ◽  
Catalytic Application ◽  
Scaffolding Ligands

Biaryl scaffolding ligands form dicobalt clusters, which serve as efficient catalysts in enaminone synthesis under ambient conditions.

Cobalt complexes of redox noninnocent azo-aromatic pincers. Isolation, characterization, and application as catalysts for the synthesis of quinazolin-4(3H)-ones

2020 ◽  
Vol 49 (25) ◽  
pp. 8448-8459 ◽  
Author(s):  
Suman Sinha ◽  
Siuli Das ◽  
Rakesh Mondal ◽  
Sutanuva Mandal ◽  
Nanda D. Paul
Keyword(s):  
Cobalt Complexes ◽  
Synthesis And Characterization ◽  
Catalytic Application ◽  
Redox Noninnocent

Herein we report synthesis and characterization of three new cobalt(ii)-complexes of redox noninnocent arylazo ligands and unveil their catalytic application towards the synthesis of a variety of substituted quinazolin-4(3H)-ones.

Cobalt complexes of pyrrolecarboxamide ligands as catalysts in nitro reduction reactions: influence of electronic substituents on catalysis and mechanistic insights

2017 ◽  
Vol 4 (2) ◽  
pp. 324-335 ◽  
Author(s):  
Sunil Yadav ◽  
Sushil Kumar ◽  
Rajeev Gupta
Keyword(s):  
Substrate Binding ◽  
Cobalt Complexes ◽  
Redox Potentials ◽  
Reduction Reactions ◽  
Square Planar ◽  
Aromatic Heterocyclic ◽  
Mediated Reduction ◽  
Nitro Reduction

Square-planar Co3+ complexes, displaying substrate binding abilities and facile Co3+/2+ redox potentials, function as efficient catalysts for hydrazine-mediated reduction of aromatic, heterocyclic, as well as aliphatic nitro substrates.

scholarly journals [Co(TPP)]–Catalyzed Carbene Transfer from Acceptor–Acceptor Iodonium Ylides via N-enolate Carbene Radicals

2021 ◽  
Author(s):  
Roel Epping ◽  
Mees Hoeksma ◽  
Eduard Bobylev ◽  
Simon Mathew ◽  
Bas de Bruin
Keyword(s):  
Radical Intermediate ◽  
Radical Intermediates ◽  
Ligand Modification ◽  
Catalytic Application ◽  
Square Planar ◽  
Carbene Transfer ◽  
Cyclic Compounds ◽  
Catalytic Cycles ◽  
Iodonium Ylides

Abstract Square-planar cobalt(II)-systems have emerged as powerful carbene transfer catalysts for the synthesis of numerous (hetero)cyclic compounds via cobalt(III)-carbene radical intermediates. Spectroscopic detection and characterization of reactive carbene radical intermediates is limited to a few scattered experiments, centering around mono-substituted carbenes. Here, we reveal the unique formation of disubstituted cobalt(III)-carbene radicals derived from a cobalt(II)-porphyrin complex and acceptor–acceptor λ3-iodaneylidenes (iodonium ylides) as carbene precursors and their catalytic application. Particularly noteworthy is the fact that iodonium ylides generate novel bis-carbenoid species via reversible ligand modification of the paramagnetic [Co(TPP)]-catalyst. Two interconnected catalytic cycles are involved in the overall mechanism, with a mono-carbene radical and an unprecedented N-enolate-carbene radical intermediate at the heart of each respective cycle. Notably, N-enolate formation is not a deactivation pathway, and both the N-enolate and carbene radical moieties can be transferred to styrene. The findings are supported by extensive experimental and computational studies.

Complexes of substituted benzothiazoles. 1. Cobalt(II), copper(II), and zinc(II) complexes of 2,2′-o-phenylenebisbenzothiazole; a potential N or S donor ligand

1979 ◽  
Vol 57 (1) ◽  
pp. 1-7 ◽  
Author(s):  
John Charles Thomas Rendell ◽  
Laurence Kenneth Thompson
Keyword(s):  
Copper Chloride ◽  
Cobalt Complexes ◽  
Chloride Complex ◽  
Donor Ligand ◽  
X Ray ◽  
Square Planar ◽  
Hydrogen Bonded

A series of cobalt(II), copper(II), and zinc(II) complexes of the title ligand are reported. 1:1 complexes of cobalt and zinc, M(OBT)X2 (M = Co, Zn; X = Cl, Br, I, NCS), have four-coordinate pseudo-tetrahedral stereochemistries while for copper (X = Cl, Br), distorted square geometries are suggested. Six-coordinate 1:1 derivatives are also obtained for cobalt and copper, M(OBT)(NO3)2 (M = Co, Cu), while the 1:2 derivative Cu(OBT)2(ClO4)2-2H2O may be square planar. OBT appears to coordinate as an N2 donor in all cases. Preliminary X-ray data confirm a distorted square CuN2Cl2 structure for the copper chloride complex. Hydrogen bonded chloroform solvate molecules appear to be present in three cobalt complexes (X = Cl, Br, NCS).

Synthesis and catalytic application of [PPP]-pincer iron, nickel and cobalt complexes for the hydrosilylation of aldehydes and ketones

2018 ◽  
Vol 42 (20) ◽  
pp. 16583-16590 ◽  
Author(s):  
Xinghao Qi ◽  
Hua Zhao ◽  
Hongjian Sun ◽  
Xiaoyan Li ◽  
Olaf Fuhr ◽  
...  
Keyword(s):  
Cobalt Complexes ◽  
Catalytic Performance ◽  
Catalytic Application ◽  
Aldehydes And Ketones ◽  
Iron Nickel

The catalytic performance of [PPP]-pincer hydrido Fe, Ni and Co complexes for the hydrosilylation of aldehydes and ketones was explored.

Synthesis of [POCOP]-pincer iron and cobalt complexes via Csp3–H activation and catalytic application of iron hydride in hydrosilylation reactions

RSC Advances ◽  
2015 ◽  
Vol 5 (20) ◽  
pp. 15660-15667 ◽  
Author(s):  
Shaofeng Huang ◽  
Hua Zhao ◽  
Xiaoyan Li ◽  
Lin Wang ◽  
Hongjian Sun
Keyword(s):  
Bond Activation ◽  
Cobalt Complexes ◽  
Pincer Ligand ◽  
Catalytic Application ◽  
Iron Hydride

Csp3–H bond activation in pincer ligand (Ph2PO(o-C6H2-(4,6-tBu2)))2CH2 (1) (POCH2OP) was achieved by Fe(PMe3)4 and CoMe(PMe3)4 to afford (POCHOP)Fe(H) (PMe3)2 (2) and (POCHOP)Co(PMe3)2 (4).

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

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