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1.
Chem Commun (Camb) ; 59(94): 14036-14039, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37920990

RESUMO

Our recent Communication (S. R. Khan et al., Chem. Commun., 2022, 58, 2208) suggested that CO2 can be used as a potential oxidant under light irradiation without using any catalyst for the oxidation of aldehydes to acids at room temperature. The Comment based on the published literature on the catalytic oxidation of aromatic aldehydes by CO2 and thermodynamical data argued on the realism of the experimental data.

2.
Langmuir ; 39(48): 17295-17307, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37987736

RESUMO

The current study highlights the successful integration of an in silico design with experimental validation to create a highly effective corrosion inhibitor for copper (Cu) surfaces. The synthesized sulfonated zinc phthalocyanine (Zn-Pc) is electrochemically characterized and demonstrates an impressive 97% inhibition efficiency, comparable to the widely used industrial corrosion inhibitor, BTA, for Cu surfaces. The corrosion inhibition is comprehensively analyzed through potentiodynamic polarization and impedance spectroscopy techniques, supported by their respective equivalent circuits. Furthermore, the sample undergoes thorough characterization using scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, contact angle measurements, and atomic force microscopy. Density functional theory calculations reveal that sulfonated Zn-Pc exhibits the highest interaction energy, underscoring its exceptional inhibition properties. These results open possibilities for utilizing computational methods to design and optimize corrosion inhibitors for protection of Cu surfaces.

3.
Chem Commun (Camb) ; 59(10): 1313-1316, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36636985

RESUMO

The first photochemical synthesis of linear carbonates from the reaction of CO2 with alcohols using a silver-doped ceria nanocomposite at room temperature under visible light irradiation is described. DFT calculations suggested the electron transfer from Ag 4d states to Ce 4f states in the composite for the photoreaction.

4.
Chem Commun (Camb) ; 58(13): 2208-2211, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35072682

RESUMO

A novel visible light-driven catalyst-free oxidation of aldehydes using CO2 both in batch and flow photoreactors to get corresponding acids along with the formation of CO in the effluent gas is described.

5.
Mater Sci Eng C Mater Biol Appl ; 91: 208-217, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30033248

RESUMO

In the present study a number of fatty acid constituted ionic liquids having tetramethylguanidinium ion as a cationic counterpart were synthesized by neutralization of 1,1,3,3­tetramethyguanidine (TMG) with fatty acids having varying degree of alkyl chain and olefinic bonds. The structure of the synthesized ionic liquids was thoroughly characterized using a number of analytical tools such as TGA, FT-IR, 1H and 13C NMR spectroscopy. The tribo-properties of the obtained ionic liquids as high performance anti-friction and wear reducing additives were studied in different dosage to mineral base oil under condition of mixed/boundary lubrication. It was found that the anti-wear and friction reduction properties of blends were improved with increasing the alkyl chain in constituted fatty acid ionic liquids.


Assuntos
Ácidos Graxos/química , Guanidina/síntese química , Líquidos Iônicos/síntese química , Aço/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Fricção , Guanidina/química , Líquidos Iônicos/química , Lubrificação , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria
6.
Dalton Trans ; 43(21): 8054-61, 2014 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-24718600

RESUMO

A rhenium-oxo complex such as methyltrioxorhenium (MTO) has been homogeneously immobilized on a Schiff base modified graphene oxide (GrO) support via covalent bonding. The loading of MTO on GrO nanosheets was monitored by FTIR, TG-DTA, and elemental analyses. The developed heterogeneous catalyst is found to be efficient for the oxidation of various amines to the corresponding N-oxides using hydrogen peroxide as an oxidant in high to excellent yields. At the end of the reaction, the catalyst is readily recovered by filtration and reused for subsequent runs. After the third run, the catalyst showed a marginal decrease in catalytic activity owing to the leaching of the MTO complex from the support.

7.
Org Biomol Chem ; 9(9): 3370-4, 2011 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-21412524

RESUMO

Copper catalyzed [3+2] cycloaddition "click method" provided an efficient and high yielding immobilization of cobalt(II) Schiff base to the azido-functionalized MeOPEG(5000); whereas the direct reaction between MeOPEG(5000) and Co(II) Schiff base did not produce any immobilization. The prepared catalyst was tested for the oxidative dehydrogenation of various secondary amines using TBHP as oxidant and could be easily recovered by precipitation with diethyl ether at the end of the reaction.

8.
Chem Commun (Camb) ; 47(5): 1610-2, 2011 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-21109899

RESUMO

The first report on the use of chlorotriphosphazenyl anchored mesoporous silica as a novel support for the immobilization of oxo-vanadium Schiff base moieties is described. The resulting heterogeneous material showed better catalytic activity than homogeneous as well as silica immobilized oxo-vanadium Schiff base for the hydroxylation of benzene with hydrogen peroxide.

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