Voltammetry of quinones in anionic micelles

A voltammetric study of a series of differently substituted benzenediols was carried out in aq. anionic micellar solns. The partitioning of the probes between the bulk aq. and the micellar pseudophase affects both the obsd. currents and the half-wave potentials. The results are discussed in terms of probe-aggregate interactions and compared with kinetics of electron transfer reactions involving benzenediol/quinone couples

Diffusion processes in amphiphilic aggregate systems

The diffusion properties of aggregates of amphiphilic mols. (e.g., micelles, microemulsion) are discussed. The interaction of these organized assemblies with water-sparingly sol. org. compds. and ions and the consequent influence on the transport of these species is examd. as well as their effect on the transfer of solutes through a membrane

Electron-transfer equilibria and kinetics of N-alkylphenothiazines in micellar systems

The kinetics and equil. of electron transfer between N-alkylphenothiazines (alkyl = Me, Et, Bu, dodecyl) and aquoiron(III)/(II) in the presence of various micelle-forming surfactants (hexadecyltrimethylammonium methanesulfonate, sodium dodecylsulfate, and Triton X100) were investigated. The presence of the micelles strongly affects rates and equil., and the dependence of these changes on the hydrophobicity of the alkyl chain is examd

Host-guest Chemistry in the Gas Phase and at the Gas-solid Interface: Fundamental Aspects and Practical Applications

The study of host-guest interactions has recently expanded from solution chemistry to the gas phase, where solvent effects are not present, allowing better understanding of the intrinsic phenomena responsible for molecular recognition. Important aspects under investigation include the mechanism of interaction, the identification of binding groups, as well as the discovery of structural requirements for the host to undergo inclusion complexation. The information gained from these gas phase studies can be exploited to design new practical applications of host-guest chemistry, particularly when gas-solid interactions are involved. Analytical devices such as gas sensors and chromatographic adsorbing cartridges take advantage of the structural recognition capability of the host to achieve high levels of selectivity

Formation of Condensation Products in Advanced Oxidation Technologies : The Photocatalytic Degradation of Dichlorophenols on TiO2

Photocatalytic treatment of dichlorophenols (DCPs) leads to the formation of condensation products. These products were identified as polyhydroxyPCBs. Depending on the initial DCP isomer, different extents and yields of polyhydroxyPCB formation (up to 1%) and different types of polyhydroxyPCBs were observed. The formation of dehalogenated hydroxyphenols and hydroxytrichlorobiphenyls in the presence of oxygen suggests that, in addition to oxidative pathways, reductive pathways are also operating. In contrast to direct photolysis by UV irradiation, no evidence of hydroxypolychlorodibenzo-p-dioxins or dibenzofurans was found. PolyhydroxyPCBs are destroyed in the same time window as the initial DCP. The similarities between this photocatalytic process and other advanced oxidation processes (AOP) based on (OH)-O-. radical chemistry are discusse