Ligand surfactant

Progress in the application of Arsenazo 111 reagent in analytical chemistry has recently been discussed [1]. A review of systems based on ternary and multicomponent complexes recently developed for spectrophotometric determination of elements have been presented [2]. The use of mixed ligand, surfactant sensitized, ion-association, flotation, derivative and FIA techniques has been discussed. 

Svobodova E, Cibulka R, Hampl I, Smidrkal J, Liska F. Metal ion transport through bulk liquid membrane mediated by cationic ligand surfactants. Collection Czechoslovak Chem Commun 2005 70 441-465. 

Scrimin P, Tonellato (1991) Ligand Surfactants Aggregation, Cations Binding and Transport and Catalytic Properties. In Mittal KL, Sha DD (eds) Surfactants in Solution, Plenum Press, New York, Vol. 11, p 339... 

Nanopartieles may be stabilized following a few protocols that include (i) electrostatic stabilization, (ii) steric stabilization, (iii) elctrosteric stabilization, and (iv) stabilization by ligand, surfactant, or polymer. ... 

Metallomicelles made up of ligand surfactants and bound metal ions have been studied extensively as artificial hydrolytic metallo-enzymes. Many such systems have become large and complex, but a study of a simple (1 1) Co(II) complex with triethanolamine showed that in the presence of CTAB or Triton X-100, it could catalyse PNPP (67) hydrolysis at pH 7 with a rate enhancement factor of 1000-fold. " ... 

As many gemini surfactants possess lower critical micelle concentrations (CMC) than their single-chained analogs [3], the pseudogemini complexes possessed CMC s lower than those of the individual ligand surfactants. 

The rate of cleavage of 1 has been studied in the absence and presence of metallomicelles of surfactant with tridentate ligand head groups (10 and 11) at a constant pH, but the observed kinetic data are not snfficient to provide a quantitative explanation of these data in terms of a micellar kinetic model. However, these kinetic data may provide a qualitative assessment of catalytic factor (Y) due to aqueous metal ion catalysis (Y" ), metal ion-tridentate Ugand complex catalysis (Y ), and metal ion-tridentate ligand surfactant complex catalysis (Y ls), xhns, Y = (k b kg)/k, = (k m - - ko)/ko, and Y ls =... 

It turned out that the dodecylsulfate surfactants Co(DS)i Ni(DS)2, Cu(DS)2 and Zn(DS)2 containing catalytically active counterions are extremely potent catalysts for the Diels-Alder reaction between 5.1 and 5.2 (see Scheme 5.1). The physical properties of these micelles have been described in the literature and a small number of catalytic studies have been reported. The influence of Cu(DS)2 micelles on the kinetics of quenching of a photoexcited species has been investigated. Interestingly, Kobayashi recently employed surfactants in scandium triflate catalysed aldol reactions". Robinson et al. have demonshuted that the interaction between metal ions and ligand at the surface of dodecylsulfate micelles can be extremely efficient. ... 

Yan and associates developed a method for the analysis of iron based on its formation of a fluorescent metal-ligand complex with the ligand 5-(4-methylphenylazo)-8-aminoquinoline. In the presence of the surfactant cetyltrimethyl ammonium bromide the analysis is carried out... 

It is well known, that in aqueous solutions the water molecules, which are in the inner coordination sphere of the complex, quench the lanthanide (Ln) luminescence in result of vibrations of the OH-groups (OH-oscillators). The use of D O instead of H O, the freezing of solution as well as the introduction of a second ligand to obtain a mixed-ligand complex leads to either partial or complete elimination of the H O influence. The same effect may be achieved by water molecules replacement from the inner and outer coordination sphere at the addition of organic solvents or when the molecule of Ln complex is introduced into the micelle of the surfactant. 

The aim of this work was to study the influence of a second ligand, the concentration and nature of surfactants on flumequine-sensitized fluorescence of lanthanides and the usage of such a mixed-ligand complex for fluorimetric determination of flumequine in hen meat tissues. 

In the latter function, the reagent behaves as a surfactant and forms a cationic micelle at a concentration above the critical micelle concentration (1 x 10 4M for CTMB). The complexation reactions occurring on the surface of the micelles differ from those in simple aqueous solution and result in the formation of a complex of higher ligand to metal ratio than in the simple aqueous system this effect is usually accompanied by a substantial increase in molar absorptivity of the metal complex. 

One of the main challenges in the field is the controlled crystalhzation of the nanoparticles into 3D super-lattices, similar to artificial opals but including much smaller individual particles. For this we have used electrically charged stabihzers (ligands and surfactants). For example, the photochemical decomposition of the precursor [Sn(NMe2)2]2 in the presence of HDA... 

The preparation and study of metal nanoparticles constitutes an important area of current research. Such materials display fascinating chemical and physical properties due to their size [62, 63]. In order to prevent aggregation, metal nanoparticles are often synthesized in the presence of ligands, functionalized polymers and surfactants. In this regard, much effort has focused on the properties of nanoparticles dispersed into LCs. In contrast, the number of nanoparticles reported that display liquid crystal behavior themselves is low. Most of them are based on alkanethiolate stabilized gold nanoparticles. 

---