Rate enhancement via micelle encapsulation for room temperature metal catalyzed Ce(IV) oxidation of p-chlorobenzaldehyde to p-chlorobenzoic acid in aqueous medium at atmospheric pressure

Micellar and Transition Metal Ion Catalysed Oxidation of Pentanol in Aqueous Medium

Micelles and 4d- or 5d-transition metal ions have been proved to be effective catalysts for the oxidation of 1-pentanol by Ce(IV) in aqueous medium under pseudo 1st order reaction conditions at 258C. Although cationic micelles show a speed retarding effect, anionic SDS micelles accelerate the reaction rate. The Ir(III) and Ru(III) catalysed reactions show shorter half-lives at micromolar concentration. Active Ce(IV) species are also identified and an explanation of the different catalytic activities of metal ions and micelles is presented. The accumulation of the substrate in the Stern-layer of the SDS micelles is detected. The reaction product is confirmed by melting point analysis, a 2,4-DNP test, and by IR and NMR studies.

Thermochromism of Highly Luminescent Photopolymer Flexible Films Based On Eu (III) Salts Confined in Polysulfone

Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)₄]^- anion. The studied Eu(III) salts were [C₁₆Pyr][Eu(fod)₄] (1), and the previously reported [Chol][Eu(fod)₄]. C₁₆Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (ϕ) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)₄] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)₄/PSU presented a strong temperature dependence with a ratiometric thermal behavior.

Potential application of Micellar nanoreactor for electron transfer reactions mediated by a variety of oxidants: A review

Surfactant, either natural or synthetic, forms a different type of aggregates among which 'Micelle' is truly an important dynamic surfactant aggregate, having a different region to interact with several organic, inorganic, and biomolecules; therefore the practical use of micelle is rapidly growing day-to-day. Surfactant-micelle, looks like a reactor of nano-dimension, govern a variety of reactions in aqueous media extensively. Oxidation is one of the vital reaction, take a part in the course of several organic transformations which are not very easy to execute in water media alone due to the solubility problem. Moreover, in order to achieve a quick transformation overcoming several difficulties the utility of micellar media became an excellent innovation, that's why nowadays, the surfactant and its aggregates are a focus of interest to the researcher of synthetic field and thus its practical applicability has been tremendously cultivated over the few decades. It is, therefore, useful to introduce some basic concepts regarding the aggregation of surfactants. Subsequently, we emphasize the importance of micellar media on the kinetics of oxidation reactions mediated by several metal ions with a special emphasis on their catalytic role.

Partitioning of reactive yellow 86 between aqueous and micellar media studied by differential absorption spectroscopy

The present study describes the partitioning of a reactive dye, reactive yellow 86, between aqueous and micellar media of a cationic surfactant (cetyltrimethyl ammonium bromide, CTAB), as well as an anionic surfactant (sodium dodecyl sulphate, SDS). In a systematic investigation, we have recorded the UV–vis absorption spectra of the dye as a function of surfactant’s concentration above and below the critical micelle concentration (CMC). Absorption spectra display a red shift in the case of CTAB and a hypochromic shift upon using SDS. The partition coefficient (Kx) was calculated using differential absorption data, and the value of free energy of partition (ΔGp) was calculated using this Kx value. The results revealed that the dye is solubilized in CTAB micelles to a greater extent than in SDS micelles.

Optimal Process Condition for Room Temperature Hetero-Aromatic Nitrogen Base Promoted Chromic Acid Oxidation of p-Chlorobenzaldehyde to p-Chlorobenzoic Acid in Aqueous Micellar Medium at Atmospheric Pressure

The present paper describes the kinetics of oxidation of p-chlorobenzaldehyde by chromic acid in aqueous and surfactant media in the presence of a promoter at 303 K. The rate constants were found to increase with introduction of hetero-aromatic nitrogen base promoters such as picolinic acid (PA), 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen). The product p-chlorobenzoic acid has been characterized by NMR. The mechanism of both unpromoted and promoted reaction paths has been proposed. In presence of the anionic surfactant sodium dodecyl sulfate (SDS), cationic surfactant N-cetylpyridinium chloride (CPC) and non-ionic surfactant Triton X-100 (TX-100) the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation. Both SDS and TX-100 produce a normal micellar effect whereas CPC produces a reverse micellar effect in the presence of p-chlorobenzaldehyde.

A review on the advancement of ether synthesis from organic solvent to water

Ethers have been synthesized by different protocols, this review aims to bring the attention of scientists working in the field of industrial chemistry, green chemistry, and catalysis towards the potential future of ether synthesis in micellar media.

Room Temperature Micellar Catalysis on Permanganate Oxidation of Butanol to Butanal in Aqueous Medium at Atmospheric Pressure

Oxidation kinetics of 1-butanol by permanganate have been carried out in the presence of surfactant in aqueous acidic medium to observe the micellar effect on rate. The oxidation kinetics were studied by UV–VIS spectrophotometry. The presence of cationic N-cetylpyridinium chloride (CPC) micelles was found to accelerate the reaction rate and this effect has been explained by the partitioning of the reactants in micelle and also by considering the hydrophobic and electrostatic interactions between the surfactant and reactants. The alcohol was quantitatively oxidized to the carbonyl compound, which was identified by the preparation of 2,4-DNP derivatives. The probable mechanism is proposed and pseudo-first-order rate constants are calculated. The cationic surfactant (CPC) accelerates the reaction. The critical micelle concentration (CMC) value of the CPC micelle has been determined from the plot of rate constant values at different CPC concentration.

Modernization of surfactant chemistry in the age of gemini and bio-surfactants: a review

This review contains elaborate discussions on the efficiencies of gemini and bio-surfactants as modern generation green chemicals in various fields.