scholarly journals Use of CuO encapsulated in mesoporous silica SBA-15 as a recycled catalyst for allylic C–H bond oxidation of cyclic olefins at room temperature

RSC Advances ◽  
2017 ◽  
Vol 7 (31) ◽  
pp. 19330-19337 ◽  
Author(s):  
Saadi Samadi ◽  
Akram Ashouri ◽  
Mehdi Ghambarian
Keyword(s):  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Room Temperature ◽  
Cuo Nanoparticles ◽  
Tert Butyl ◽  
Cyclic Olefins

CuO nanoparticles were deposited on SBA-15 in three routes. The catalytic activity of these catalysts was examined on the allylic C–H bond oxidation of cyclic olefins using tert-butyl p-nitrobenzoperoxoate as oxidant at room temperature.

Oxovanadium(IV), Nickel(II) and Palladium(II) Complexes of Tridentate Salicylaldiminates Derived from 2,4-Di-ter-butyl-6-aminophenol

2001 ◽  
Vol 56 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Veli T. Kasumov
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
High Catalytic Activity ◽  
Tert Butyl ◽  
Preliminary Activation

Abstract Several new binuclear nickel(II), oxovanadium(IV) and palladium(II) complexes (MLX) of tridentate salicylaldimines (LXH2) obtained from substituted salicylaldehydes and 2,4-di-tert-butyl-6-aminophenol, as well as mononuclear nickel(II) and oxovanadium(IV), MQx nH2O, complexes with hydrogenated LX H2 ligands (QXH2) have been prepared and their spectroscopic, magnetic and catalytic activity (for PdLx) have been investigated. NiLx and VOLx complexes when dissolved in pyridine, take up three or two pyridine molecules to form six coordinated complexes, respectively. The Ni(II) and VO(IV) complexes obtained from QXH2 can be formu­lated as NiQx-3H2O and VOQx H2O. All VO(IV) complexes have been characterized by ESR parameters. It has been found that some PdLx complexes without any preliminary activation, in EtOH, THF and DMF exhibit high catalytic activity in the hydrogenation of nitrobenzene or cyclohexene at room temperature and at 30 -40 °C under 760 torr H2. When this reaction has been carried out in the ESR cavity at room temperature the triplet of 12 line multiplets due to the nitroxyl type coordinated radical (g = 2.013, AN = 10 G, AH = 0.8 G) was detected.

The big effect of a small change: formation of CuO nanoparticles instead of covalently bound Cu(ii) over functionalized mesoporous silica and its impact on catalytic efficiency

2020 ◽  
Vol 49 (29) ◽  
pp. 10138-10155
Author(s):  
Trisha Das ◽  
Debdas Singha ◽  
Mahasweta Nandi
Keyword(s):  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Catalytic Efficiency ◽  
Cuo Nanoparticles ◽  
Functionalized Mesoporous Silica ◽  
Small Change ◽  
Covalently Bound

Covalently bound copper(ii) and CuO nanoparticles on mesoporous silica have been prepared by changing the addition sequence of reagents; the latter shows better catalytic activity.

Bildung von Alkylcarbenium-Ionen im System Aluminium-(Gallium-)halogenid/Halogenwasserstoff / Formation of Alkylcarbenium Ions in the System Aluminium (Gallium) Halide/ Hydrogen Halide

1979 ◽  
Vol 34 (4) ◽  
pp. 548-552 ◽  
Author(s):  
Franz Kalchsclimid ◽  
Erwin Mayer
Keyword(s):  
Catalytic Activity ◽  
Lewis Acids ◽  
Room Temperature ◽  
Hydrogen Halide ◽  
Carbenium Ions ◽  
Tert Butyl ◽  
No Formation ◽  
Slow Decomposition

Abstract The tert-butyl cation is formed in the reaction of tert-BuCl with AlCl3 or GaCl3 in anhydrous liquid HCl as a solvent, or of tert-BuBr with AlBr3 in HBr. At - 30 °C solutions of [C(CH3)3+] are stable. At room temperature very slow decomposition occurs over months. In the systems BCI3/HCl, InCl3/HCl and BBr3/HBr no formation of [C(CH3)3+] from the corresponding tert-butyl halide was observed. The tert-amyl cation can be stabilized only in AlBr3/HBr. The iso-propyl cation is not stable in any of the systems investigated. The ability of the Lewis acids employed to form carbenium ions corresponds with their catalytic activity in Friedel-Crafts alkylations.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

2020 ◽  
Vol 75 (9-10) ◽  
pp. 851-857
Author(s):  
Chong Chen ◽  
Fule Wu ◽  
Jiao Ji ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Structural Characterization ◽  
Room Temperature ◽  
Molecular Structures ◽  
Cationic Complex ◽  
Neutral Complex ◽  
Ancillary Ligands ◽  
X Ray ◽  
X Ray Crystallography

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.

RhNPs supported on N-functionalized mesoporous silica: effect on catalyst stabilization and catalytic activity

2021 ◽  
Author(s):  
Israel T. Pulido-Díaz ◽  
Alejandro Serrano-Maldonado ◽  
Carlos César López-Suárez ◽  
Pedro A. Méndez-Ocampo ◽  
Benjamín Portales-Martínez ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Functional Groups ◽  
Hydrogenation Catalysts ◽  
Functionalized Mesoporous Silica ◽  
Catalyst Stabilization ◽  
Shape And Size

RhNPs supported on mesoporous silica functionalized with nicotinamide groups provided active hydrogenation catalysts for several functional groups, wherein the shape and size of the RhNPs are maintained after catalysis.

Catalytic activity of CuGHK peptide-based porous material

2021 ◽  
Author(s):  
Francisco G. Cirujano ◽  
Nuria Martin ◽  
Neyvis Almora-Barrios ◽  
Carlos Martí-Gastaldo
Keyword(s):  
Catalytic Activity ◽  
Porous Material ◽  
Active Sites ◽  
Room Temperature ◽  
Side Chain ◽  
Periodic Distribution ◽  
Lysine Side Chain ◽  
One Step

Room temperature one-step synthesis of the peptide-based porous material with a periodic distribution of pockets decorated with lysine side chain active sites behaves as a heterogeneous organocatalyst. The pockets are...

A Ag–Pd alloy supported on an amine-functionalized UiO-66 as an efficient synergetic catalyst for the dehydrogenation of formic acid at room temperature

2016 ◽  
Vol 6 (3) ◽  
pp. 869-874 ◽  
Author(s):  
Shu-Tao Gao ◽  
Weihua Liu ◽  
Cheng Feng ◽  
Ning-Zhao Shang ◽  
Chun Wang
Keyword(s):  
Catalytic Activity ◽  
Formic Acid ◽  
Room Temperature ◽  
High Catalytic Activity ◽  
Amine Functionalized ◽  
Pd Alloy

Ag–Pd alloys deposited on an amine-functionalized UiO-66(NH2–UiO-66) have been successfully prepared via a pre-coordination method and used as a AgPd@NH2–UiO-66 catalyst with 100% H2 selectivity and a high catalytic activity.

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