Suitably Band‐aligned MOF derived Ni2P/MnO2 Heterostructure With Ni(+1) Coordination Surface Sites For Self‐Coupling of Aryl Halides to Bi‐aryls

Mild Temperature Copper-Catalyzed Amination of Aryl Halides with Aqueous Ammonia in the Presence of Pyridyldiketone Ligands

10.26434/chemrxiv.7756886.v1 ◽

2019 ◽

Author(s):

Racha Abed Ali Abdine ◽

Anna Walczak ◽

Sultan Abu A Aeash ◽

Gracjan Kurpik ◽

Artur R. Stefankiewicz ◽

...

Keyword(s):

Catalytic System ◽

Aqueous Ammonia ◽

Aryl Halides ◽

Efficient Coupling ◽

Ambidentate Ligand ◽

Mild Temperature

Ambidentate ligand pyridyldiketones were used in combination with copper to catalyze maintain of aryl halides under very mild temperatures. This novel catalytic system allow efficient coupling in one of the smoothest conditions ever reported in literature.

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Carbon-Heteroatom Cross-Coupling via an Electronically Excited Nickel (II) Complex

10.26434/chemrxiv.9736049.v1 ◽

2019 ◽

Author(s):

Randolph Escobar ◽

Jeffrey Johannes

Keyword(s):

Energy Transfer ◽

Functional Groups ◽

Cross Coupling ◽

Reductive Elimination ◽

Aryl Halides ◽

Coupling Reactions ◽

General Methodology ◽

Cross Coupling Reactions ◽

Electronically Excited ◽

Energy Transfer Pathway

<div>While carbon-heteroatom cross coupling reactions have been extensively studied, many methods are specific and</div><div>limited to a set of substrates or functional groups. Reported here is a method that allows for C-O, C-N and C-S cross coupling reactions under one general methodology. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel (II) complex, is responsible for the key reductive elimination step that couples aryl halides to 1° and 2° alcohols, anilines, thiophenols, carbamates and sulfonamides.</div>

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Mercury Removal from Wastewater by Steamed Hoof Powder

Water Science & Technology ◽

10.2166/wst.1999.0340 ◽

1999 ◽

Vol 40 (7) ◽

pp. 109-116 ◽

Cited By ~ 4

Author(s):

M. H. Ansari ◽

A. M. Deshkar ◽

P. S. Kelkar ◽

D. M. Dharmadhikari ◽

M. Z. Hasan ◽

...

Keyword(s):

Heavy Metals ◽

Adsorption Capacity ◽

Adsorption Process ◽

Adsorption Equilibrium ◽

Light Metal ◽

Mercury Removal ◽

High Adsorption ◽

Surface Sites ◽

Ph Values ◽

High Adsorption Capacity

Steamed Hoof Powder (SHP), size < 53μ, was observed to have high adsorption capacity for Hg(II) with >95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

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Chiral Mn(III) Salen Complex Immobilized on CuFe2O4@SiO2-NH2 NPs: A Cheap and Efficient Catalyst for N-arylation of Aryl Halides and Phenylboronic Acid Under Mild Conditions

Letters in Organic Chemistry ◽

10.2174/1570178616666190919110639 ◽

2020 ◽

Vol 17 (11) ◽

pp. 857-863

Author(s):

Mohammad Ali Nasseri ◽

Seyyedeh Ameneh Alavi ◽

Milad Kazemnejadi ◽

Ali Allahresani

Keyword(s):

Phenylboronic Acid ◽

Significant Loss ◽

Aryl Halides ◽

Coupling Reactions ◽

Efficient Catalyst ◽

Aryl Chlorides ◽

Mild Conditions ◽

Cross Coupling Reactions ◽

Salen Complex ◽

Ft Ir

A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates. The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX, XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant loss of activity.

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Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

Current Organic Synthesis ◽

10.2174/1570179415666180913131905 ◽

2019 ◽

Vol 16 (1) ◽

pp. 173-180

Author(s):

Mingwei Chen ◽

Jinyu Hu ◽

Xiaoli Tang ◽

Qiming Zhu

Keyword(s):

Transition Metal ◽

Oxidation State ◽

Coupling Reaction ◽

Aryl Halides ◽

Metal Species ◽

Good Substrate ◽

Active Metal ◽

Homocoupling Reaction ◽

Catalytic Cycles ◽

Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

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Work function studies of propylene, acetylene, hydrogen and nitrogen chemisorption on molybdenum

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19822996 ◽

1982 ◽

Vol 47 (11) ◽

pp. 2996-3003

Author(s):

Zdeněk Bastl

Keyword(s):

Work Function ◽

Surface Topography ◽

Surface Coverage ◽

Dissociative Chemisorption ◽

Complete Coverage ◽

Surface Sites ◽

Function Change ◽

Work Function Change

The work function changes of vacuum deposited molybdenum films caused by the chemisorption of propylene, acetylene, hydrogen and nitrogen were measured using the Kelvin vibrating capacitor method. During the hydrocarbon chemisorption, the work function increased in a low surface coverage region but decreased at the higher surface coverages. The saturation values of the work function changes corresponding to complete coverage of the surface by chemisorbed propylene and acetylene equal -0.08 eV and -0.42 eV, respectively. The observed dependences of the work function change on surface coverage are interpreted by the dissociative chemisorption of hydrocarbons on a limited number of surface sites which are simultaneously the sites of preferred adsorption. The extent of dissociation decreases in the adsorption with the increasing surface coverage. The results of the study of the work function changes induced by the hydrogen and nitrogen chemisorption enabled to draw several conclusions on the surface topography of the used films.

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A topological quantum-chemical study of the chemisorption of carbon monoxide on the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19901907 ◽

1990 ◽

Vol 55 (8) ◽

pp. 1907-1919

Author(s):

Jiří Pancíř ◽

Ivana Haslingerová

Keyword(s):

Carbon Monoxide ◽

Quantum Chemical ◽

Co Adsorption ◽

Quantum Chemical Study ◽

Chemical Study ◽

Dissociative Chemisorption ◽

Frontier Orbitals ◽

Surface Sites ◽

Charged Surfaces ◽

Topological Quantum

A semiempirical quantum-chemical topological method is applied to the study of the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir and the nondissociative as well as dissociative chemisorption of carbon monoxide on them. On Ni, dissociative chemisorption is preferred to linear capture, whereas on Pd and Pt, linear capture is preferred although dissociative chemisorption is also feasible. On Rh and, in particular, on Ir, dissociative chemisorption is energetically prohibited. The high dissociative ability of the Ni surface can be ascribed to a rather unusual charge alteration and to the degeneracy of the frontier orbitals. Negative charges at the surface level are only found on the Ni and Pt surfaces whereas concentration of positive charges is established on the Rh and Ir surfaces; the Pd surface is nearly uncharged. Metals with negatively charged surfaces seem to be able to dissociate molecules of carbon monoxide. It is demonstrated that CO adsorption can take place on all metal surface sites, most effectively in the valley of the step. In all the cases studied, the attachment to the surface is found to be energetically more favourable for the carbon than for the oxygen.

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