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Preliminary efforts were made to identify alternative ligands for relatively greener and cheaper than triethanolamine (TEA), leading to a new ferric-oxalate-gluconate mixed ligand system as a potential alternative. Cyclic voltammetry was employed to study the mechanism involved. A low concentration of electrogenerated FeII-oxalate is transformed into FeII-gluconate, which is the reducing agent in the overall process. The influences of electrolyte medium, electrode material, nature of dye, dye concentration, material to liquor ratio (MLR), and other related parameters were studied to arrive at optimum experimental condition. Copper cathode and stainless steel anode were the material of choice. The optimum cathode current density was found to be 2.30 mA cm−2. Under optimum condition, both cotton fabric and yarn could be efficiently dyed using this electrochemical process. The electrolyte could also be recycled. Color intensity for different dyed materials was evaluated using K/S values according to the Kubelka–Munk equation. [ABSTRACT FROM AUTHOR]

Electrochemical perfluorination (ECPF) of n-hexanoyl, n-heptanoyl, n-octanoyl, n-nonanoyl and n-decanoyl chlorides was carried out under identical experimental conditions in liquid HF. The product distribution among perfluorinated carboxylic acids, perfluoro ethers, perfluoroalkanes, isomerised and fragmented products containing less number of carbon atoms was identified using 19F NMR. The selectivity of C6–C10 perfluoro carboxylic acid varied between 29 and 36%. The alkali insoluble perfluoro cyclic ether and perfluoro alkane fractions increased with increasing chain length. The increase of perfluoroalkane fractions is mainly due to decarboxylation. Cyclic ether fractions also decreased slightly with increase in chain length. Among the cyclic ethers α substituted oxolanes were the predominant products. Six membered cyclic ethers were always found to contain β substitution. The possible pathways for these products are also indicated. [ABSTRACT FROM AUTHOR]

The redox behaviour of Mn3+/Mn2+, Co3+Co2+ and Ce4+/Ce3+ mediators commonly used in indirect oxidation of organic compounds were evaluated in methane sulfonic acid on a glassy carbon working electrode employing cyclic voltammetry. Manganic methanesulfonate exhibits higher instability in dilute methanesulfonic acid. The solid MnO, formed during disproportionation on the glassy carbon electrode further affects the reproducibility. Cobaltic methanesulfonate formation occurs only at oxygen evolution region rendering the overall oxidation process less efficient. Ceric methane sulfonate formation is highly efficient over a wide acid concentration range. Ceric methanesulfonate can also be employed over a wide temperature range to oxidize different aromatic compounds. [ABSTRACT FROM AUTHOR]