Combination of best promoter and micellar catalyst for chromic acid oxidation of 1-butanol to 1-butanal in aqueous media at room temperature

Surfactant exopolysaccharide of Ochrobactrum pseudintermedium C1 has antibacterial potential: Its bio-medical applications in vitro

Since the advent of biologics in human welfare various bio-molecules have been explored. Different bacterial exopolysaccharides have proved their worth in many industrial and commercial applications. In this perspective, while exploring a surfactant exopolysaccharide of Ochrobactrum pseudintermedium C1, it is strikingly observed that it possesses a potent antibacterial property which encourages its bio-medical applications. Following isolation and purification of the said exopolysaccharide, its structural configuration and functional attributes are studied by several analytical procedures involving FTIR, ¹³C- NMR, CHN-analysis, estimation of zeta potential, XRD-study and digital tensiometry. When treated with pathological samples in vitro, it distinctly elicits its antibacterial property by exhibiting a characteristic zone of inhibition. Combined with a standard antibiotic (like ciprofloxacin), it enhances the action of antibiotic also. Mechanism of its antibacterial action is evaluated by crystal violet entrapment assay with UV-vis spectrophotometry, bacterial cell viability assay by trypan blue staining and SEM study. Results show that its basic surfactant property, anionic character, crystalline nature and scaffolding architecture are supposed to facilitate its antibacterial property which is manifested by its capability of disrupting bacterial cell envelope causing eventual cell death. In the current global scenario, an increasing threat of antibiotic resistance is prevailing due to their indiscriminate use. If used as an adjuvant with a judicious dose of antibiotic, this bio-molecule might play a significant role in bio-medicine to combat such threat.

Promising Biocompatible, Biodegradable, and Inert Polymers for Purification of Wastewater by Simultaneous Removal of Carcinogenic Cr(VI) and Present Toxic Heavy Metal Cations: Reduction of Chromium(VI) by Poly(ethylene glycol) in Aqueous Perchlorate Solutions

A spectrophotometric technique has been applied for studying the reduction of chromium(VI) by poly(ethylene glycol) (PEG) as water-soluble and nontoxic synthetic polymer at a constant ionic strength of 4.0 mol dm^-3 in the absence and presence of the ruthenium(III) catalyst. In the absence of the catalyst, the reaction orders in [Cr(VI)] and [PEG] were found to be unity and fractional first orders, respectively. The oxidation process was found to be acid-catalyzed with fractional second order in [H⁺]. The addition of Ru(III) was found to catalyze the oxidation rates with observation of zero-order reaction in [CrO₄ ^2-] and fractional orders in both [PEG] and [Ru(III)], respectively. The PEG reduces the soluble toxic hexavalent Cr(VI) as a model pollutant to the insoluble nontoxic Cr(III) complex, which is known to be eco-friendly and more safer from the environmental points of view. The acid derivative of PEG was found to possess high affinity for the removal of poisonous heavy metal ions from contaminant matters by chelation. Formation of the 1:1 intermediate complex has been kinetically revealed. A consistent reaction mechanism of oxidation was postulated and discussed.

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.

Poly[diaquo(1,10-phenanthroline-κ2N1:N10)(μ2-sulphato-κ2O:O′)copper(ii)]: hydrothermal synthesis, crystal structure and magnetic properties

Of late, hydrothermal synthesis has gained much interest in the synthesis of metal–organic hybrid complexes with fascinating architectures and topologies.

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.

Combination of Best Promoter and Micellar Catalyst for Cr(VI) Oxidation of Lactose to Lactobionic Acid in Aqueous Medium at Room Temperature

In aqueous acidic media, picolinic acid, 2,3-dipicolinic acid, and 2,6-dipicolinic acid promoted Cr(VI) oxidation of lactose to lactobionic acid has been carried out at room temperature. A possible reaction mechanism, which is based on the kinetic results and the product analysis, has been proposed. The anionic surfactant sodium dodecyl sulphate (SDS) and nonionic surfactant Triton-X-100 (TX-100) accelerate the process while the cationic surfactant N-cetylpyridinium chloride (CPC) retards the reaction.