Experimental and Computational Study of Steric and Electronic Effects on the Coordination of Bulky, Water-Soluble Alkylphosphines to Palladium under Reducing Conditions:  Correlation to Catalytic Activity

2005 ◽  
Vol 24 (5) ◽  
pp. 962-971 ◽  
Author(s):  
Rebecca B. DeVasher ◽  
Jason M. Spruell ◽  
David A. Dixon ◽  
Grant A. Broker ◽  
Scott T. Griffin ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Computational Study ◽  
Water Soluble ◽  
Electronic Effects ◽  
Reducing Conditions

Synthesis, structural characterization and cytotoxicity of a new proton transfer compound based on 2,4-diamino-1,3,5-triazine: an experimental and computational study

2021 ◽  
Author(s):  
Khodayar Gholivand ◽  
Leila Sarmadi ◽  
Nasrin Fallah ◽  
Mohammad Feraghi ◽  
Michal Dušek ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Structural Characterization ◽  
Computational Study ◽  
Water Soluble ◽  
Cytotoxic Compound ◽  
Proton Transfer Compound

In the present study, a new water-soluble proton transfer cytotoxic compound (dpp)(dapt).H2O (Dx) (where dpp = diphenylphosphinate and dapt = 2,6-diamino-4-phenyl-1,3,5-triazin-1-ium ) was synthesized and characterized by IR and NMR...

scholarly journals Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
High Molecular Weight Chitosan

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.

Novel Co(II) phthalocyanines of extended periphery and their water-soluble derivatives. Synthesis, spectral properties and catalytic activity

2017 ◽  
Vol 1149 ◽  
pp. 17-26 ◽  
Author(s):  
Anna Filippova ◽  
Artur Vashurin ◽  
Serafima Znoyko ◽  
Ilya Kuzmin ◽  
Mikhail Razumov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Spectral Properties ◽  
Water Soluble

Synthesis of a Water-Soluble Ruthenium Complex and Its Catalytic Activity for Acceptorless Alcohol Dehydrogenation in Aqueous Medium

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1644-1648 ◽  
Author(s):  
Senthilkumar Muthaiah ◽  
Anita Bhatia
Keyword(s):  
Catalytic Activity ◽  
Aqueous Medium ◽  
Ruthenium Complex ◽  
Water Soluble ◽  
Catalytic Cycle ◽  
Secondary Alcohols ◽  
Atom Economy ◽  
Hydrogen Acceptor ◽  
Alcohol Dehydrogenation ◽  
Acceptorless Alcohol Dehydrogenation

The synthesis of a ruthenium complex bearing a PN-chelating ligand is described. The complex, in the presence of KOH, enabled the synthesis of ketones from secondary alcohols in the absence of a hydrogen acceptor in aqueous medium. This synthetic protocol, which uses water as the medium, is green and has a high atom economy as it avoids the use of an acceptor and produces hydrogen as the sole ­byproduct. Mechanistic investigations revealed that the catalytic cycle involves a phosphine dissociative pathway.

scholarly journals An efficient Pd–NHC catalyst system in situ generated from Na2PdCl4 and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

2017 ◽  
Vol 13 ◽  
pp. 1735-1744 ◽  
Author(s):  
Nan Sun ◽  
Meng Chen ◽  
Liqun Jin ◽  
Wei Zhao ◽  
Baoxiang Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Imidazole Ring ◽  
Catalyst System ◽  
Water Soluble ◽  
Imidazolium Salts ◽  
Heck Reactions ◽  
Imidazolium Salt ◽  
Simple Method ◽  
Wide Range

Three PEG-functionalized imidazolium salts L1–L3 were designed and prepared from commercially available materials via a simple method. Their corresponding water soluble Pd–NHC catalysts, in situ generated from the imidazolium salts L1–L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki–Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium salt L1, bearing a pyridine-2-methyl substituent at the N3 atom of the imidazole ring, showed the best catalytic activity. Under the optimal conditions, a wide range of substituted alkenes were achieved in good to excellent yields from various aryl bromides and alkenes with the catalyst TON of up to 10,000.

Catalytic Oxidation of 2-Mercaptoethanol by Cationic Water-soluble Phthalocyaninatocobalt(II) Complexes

1997 ◽  
Vol 01 (04) ◽  
pp. 309-313 ◽  
Author(s):  
MUTSUMI KIMURA ◽  
YUJI YAMAGUCHI ◽  
TOSHIKI KOYAMA ◽  
KENJI HANABUSA ◽  
HIROFUSA SHIRAI
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Absorption Spectra ◽  
Positive Charge ◽  
Alkyl Chain ◽  
Solvent Polarity ◽  
Water Soluble ◽  
Uv Absorption Spectra ◽  
Alkyl Chains ◽  
The Stability

The cationic amphiphilic cobalt(II) phthalocyanines have been prepared, and are characterized by UV-absorption spectra in water and organic solvents and in their mixtures. The monomer–dimer transformation equilibrium was affected by solvent polarity and the length of the alkyl chains in the amphiphilic parts. All complexes are efficient catalysts for the oxidation of 2-mercaptoethanol in the presence of dioxygen. The positive charge around the complex increases the acceleration of the dissociation of 2-mercaptoethanol under neutral pH. The catalytic activity is affected by the length of the alkyl chain; consequently the stability of aggregation between cobalt(II) phthalocyanines, as catalysts for the oxidation of 2-mercaptoethanol, can be changed.

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