Water-soluble metal

The sulphonic acids are strongly acidic compounds, very soluble in water and readily give water-soluble metallic salts. 

Salts of alkyl hydrogen sulfates that are free of sulfuhc acid can be prepared from crude hydrogen sulfates containing ROSO H and sulfuhc acid in a two-step reaction. Eirst, the crude product reacts in aqueous solution with the hydroxide or carbonate of a metal whose sulfate is insoluble in water. After filtration of the insoluble metal sulfate, the necessary amount of a water-soluble metal sulfate is added to the filtrate, which precipitates the insoluble metal sulfate, leaving the desired salt of the alkyl hydrogen sulfate in solution. 

Metal- Working and Hydraulic Fluids. In the preparation of fluids for metal-working and hydrauflcs, the trend has been to replace organic-based materials with aqueous-based materials. Neodecanoic acid has found apphcation in these newer fluids as a corrosion inhibitor and a viscosity improver. For example, neodecanoic acid is used in an aqueous hydrauflc fluid concentrate for corrosion inhibition and improved antiwear properties (101), in the preparation of a thickened aqueous hydrauflc fluid to reduce viscosity loss (102), and in a water-soluble metal working oil to reduce corrosion (103). In a similar vein, neodecanoic acid has been used in antifreeze concentrates for corrosion inhibition (104). 

The Rate Constants (298 K) for the on and off Reactions of NO and CO with certain Water Soluble Metal Complexes in Aqueous Solution... 

The use of water-soluble metal catalysts for the hydrogenation of thiophenes in aqueous biphasic systems has been primarily introduced by Sanchez-Delgado and coworkers at INTEVEP S.A. [61]. The precursors RuHC1(TPPTS)2(L2) (TPPTS=triphenylphosphine trisulfonate L=aniline, 1,2,3,4-tetrahydroquinoline) and RuHC1(TPPMS)2(L2) (TPPMS=triphenylphosphine monosulfonate) were... 

For understanding these tendencies, we will consider the values of the biogeo-chemical coefficient of aqueous migration. This coefficient Cw is the ratio between the content of an element in the sum of water-soluble salts and in geological rocks. The values of Cw for certain chemical species are smaller in Arid ecosystems than those in Forest ecosystems. We can suggest two explanations. First, soils of Forest ecosystems are enriched in water-soluble metal-organic complexes (see Chapter 7). Second, most chemical species are trapped in the transpiration barrier of upper soil layers of Arid ecosystems. 

As we have seen earlier in this chapter, metal catalysts may be made soluble in water by careful design of the ligands around them. Metal catalysed reactions may also be conducted under phase transfer conditions. Here, by contrast, the metal catalyst usually resides in the organic phase and not the aqueous phase. The use of a phase transfer catalyst in these systems may be to transfer a water-soluble metal catalyst into the organic layer, or else to ensure a supply of water-soluble substrate or reagent to a catalyst already resident in the organic phase. An example of the former is the use of methyltrioctylammonium chloride to extract aqueous RhCL... 

Analogously, the SAPC catalyzed hydroformylation reaction was carried out using other water-soluble metal complexes of Pt and Co. Pt complexes in the presence of an Sn co-catalyst underwent hydrolysis of the Pt-Sn bond, which led to lower reaction selectivity. With the corresponding Co catalyst, good hydroformylation selectivities and conversions could be achieved, provided excess phosphine was used. Other authors performed hydrogenation of a,(3-unsaturated aldehydes using SAPC, and Ru and Ir water-soluble complexes. 

Rasmuson A. 1985. Mutagenic effects of some water-soluble metal compounds in a somatic eye-color test system in Drosophila melanogaster. Mutat Res 157 157-162. 

Brookhaven National Laboratory s (BNL s) biochemical recovery of radionuclides and heavy metals is a patented biochemical recovery process for the removal of metals and radionuclides from contaminated minerals, soil, and waste sites. In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals and radionuclides from solid wastes by the formation of water-soluble, metal-citrate complexes. The complex-rich extract is then subjected to microbiological biodegradation that removes most of the extracted heavy metals. 

The technology is best suited for the removal of water-soluble metals and organics. Organics that would most likely be mobilized by this process include aromatic compounds such as benzene, toluene, xylene, and phenolic compounds, as well as chlorinated solvents. Electroki-netic remediation is not a practical method of remediation for insoluble organics such as heavy hydrocarbons. 

Reduction of Double Complexes. Except for Ag/Au bimetallic nanoparticles, bimetallic nanoparticle dispersions containing Ag have not been studied extensively. One of the possible reasons is that an Ag1 ion readily reacts with a halide ion to produce water-insoluble silver halide. Also, many other water-soluble metal salts other than halides are not as suitable as precursors for the production of metallic particles by mild reduction. 

Since the ligand is basic, various protonated species may occur in solution. Specifically, if Cl is thg total concentration of ligand in solution then, ignoring any small amount present as any water-soluble metal complex, and omitting charges for the sake of generality ... 

Water-soluble metal salts of alkyllrisilanols are efficient in the reduction of surface tension. A silicone putty is made by compounding a benzene-soluble silicone polymer with silica powder and an inorganic tiller. 

It is, therefore, necesssary to have at least one component embedded in the vesicle bilayer. In general, this has been the chromophore, which can be hydrophobic, such as tetraphenylpor-phyrinatozinc(II), or amphiphilic so that it aligns in the bilayer structure with the water soluble metal containing head group in the water. 

Bhanage BM, Shirai M, Arai M et al (1999) Multiphase catalysis using water-soluble metal complexes in supercritical carbon dioxide. Chem Commun 14 1277-1278... 

Fancy DA, Denison C, Kim K, et al. Scope, limitations and mechanistic aspects of the photo-induced cross-linking of proteins by water-soluble metal complexes. Chem Biol 2000 7 697-708. 

A useful, yet almost never mentioned aspect of water or buffered extraction is its ability to remove water-soluble metal ions that can hamper a scheduled sample preparation step, for example, enzymatic proteolysis, through enzyme inhibition [45]. 

Summary Electroplating is carried out by utilizing identical electrolysis techniques as seen in methods 1 and 2, but instead of forming metal flakes or crystals, the cathode is composed of a desired metal object to be plated. To plate metal objects, the metal object is placed as the cathode, and a solution of either dilute hydrochloric acid and corresponding metal anode, or a solution of a water soluble metal salt utilizing a metal anode or inert anode, is electrolyzed using varying current to plate the desired metal object. The electrolysis process is rapid and can be carried out with success in minimal amounts of time. 

Based upon the use of nonionic surfactant systems and their cloud point phase separation behavior, several simple, practical, and efficient extraction methods have been proposed for the separation, concentration, and/or purification of a variety of substances including metal ions, proteins, and organic substances (429-441. 443.444). The use of nonionic micelles in this regard was first described and pioneered by Watanabe and co-workers who applied the approach to the separation and enrichment of metal ions (as metal chelates) (429-435). That is, metal ions in solution were converted to sparingly water soluble metal chelates which were then solubilized by addition of nonionic surfactant micelles subsequent to separation by the cloud point technique. Table XVII summarizes data available in the literature demonstrating the potential of the method for the separation of metal ions. As can be seen, factors of up to forty have been reported for the concentration effect of the separated metals. 

M NH4N03 Exchangeable metal ions, water soluble metal salts 24 h, 20°C... 

Baham, J. and Sposito, G., Chemistry of water-soluble, metal-complexing ligands extracted from an anaerobically digested sewage sludge, J. Environ. Qual., 12, 96, 1983. Berggren, D. et al., Metal solubility and pathways in acidified forest ecosystems of South Sweden, Sci. Total Environ., 96, 103, 1990. 

Most of the thermodynamic studies have been performed in aqueous solutions as the cycles and their derivatives are first of all ligands for complexation of water-soluble metal ions. Numerous compounds have been studied and, therefore, only a general overview of trends is given. More information can be find in commercial databases such as NIST Standard Reference Database 46 (Critically Selected Stability Constants of Metal Complexes) or The IUPAC Stability Constants Database (SC-Database) or in reviews <2005PAC1445> (critically evaluated data for DOTA 3 and TETA 4), <1999CCR97> (protonation constants of polyamines) and <2000CCR309> (protonation constants of polyamino-polycarboxylic acids). Overall basicity of the ligands is mostly the main determinant for values of stability constants of metal complexes. 

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