Metal chloride salts

Chloride salts (sodium chloride, potassium chloride) tend to interfere with the formation of a protective layer over metals. Chloride salts destroy the passivity of some stainless steels and cause them to fail by rapid cracking under tensile stress at temperatures higher than about 176°F (80°C). This type of failure is called chloride stress cracking (CSC) [186,194]. 

Metal catalysts, 10 46-47 Metal-catalyzed addition, polymers prepared by, 15 179-180 Metal chelation, 9 424 Metal chloride salts, 13 817-818 Metal chlorides, decomposition by acids, 13 822-824 Metal cleaning... 

Figure 4. (a) Planar bilayer membrane system for single-channel currents measurement. Soybean lecithin in n-decane was applied to a hole separating two aqueous chambers. Chambers were filled with metal chloride salt at pH 7.2. The voltage was applied to the outer cell with respect to the inner. The currents across the bilayer were recorded on a PCM recorder through a patch-clamp amplifier and a lowpass filter, (b) Typical records of current observed at -t-50.0 mV (symmetrical 0.5 M solution). Currents increase upward from the zero level shown by the dotted line in each panel. 

This metallic chloride salt then reacts with the abundant molecules of hydrogen sulfide to produce hydrochloric acid and iron sulfide. 

The PASSflow system described previously has also been functionalized with nanoparticular metal species (Pd, Ni and Pt) [116,133,122]. These nanoclusters are formed by first flowing a metal chloride salt through an anion-exchange monolith... 

Compounds 9.8 and 9.10 were further characterized for their metal binding capacity 9.8 confirmed a high and quite selective affinity for Zn , Fe and Cu , and its activation of TGF-P signaling was reversed (Fe ) or largely reduced (Zn, Cu ) by addition of metal chloride salts. RCG thus provided insight on TGF-P signalhng (several potential genes involved) and on the relevance of metal ions for this process. 

Fig. 6. Optical absorption spectra of solvated electrons at 10°C in pure water and in aqueous solutions containing (a) 2 mol kg of monovalent (Na ), divalent (Mg ) and trivalent (Tb ) metal chloride salts, (b) magnesium perchlorate, Mg(C10.j)2, with increasing concentration (1, 2 and 3 mol kg ). [Reprinted from Ref. 68, Copyright 2004, with permission from American Chemical Society.]...

We also screened group 1-15 metal chlorides searching for Lewis acids stable in aqueous solvents (Table 14-3) [22], As a model, the reaction of benzaldehyde with (Z)-l-phenyl-l-(trimethylsiloxy)propene was selected. In the first screening, the chloride salts of Fe(II), Cu(II), Zn(II), Cd(II), Infill), and Pb(II) as well as the rare earth metals [Sc(III), Y(III), Ln(III)] gave promising yields. When the chloride salts of B(III), Si(IV), PflU), P(V), Ti(IV), V(III), Ge(IV), Zr(IV), Nb(V). Mo(V), Sn(IV), Sb(V), Hf(IV), Ta(V), W(VI), Re(V), and Tl(III) were used, decomposition of the silyl enol ether occurred rapidly and no aldol adduct was obtained. This is because hydrolysis of such metal chlorides is very fast and the silyl enol ether was protonated and then hydrolyzed to afford the corresponding ketone. On the other hand, no product or only a trace amount of the product was detected using the metal chloride salts of Li(l), Na(I), Mg(II), Al(III), K(I), Ca(Il),... 

The oxyhydrochlorination catalyst was prepared according to the procedure of Conner et al. [9]. The material was prepared in nonaqueous solvents by successive impregnation of metal chloride salts onto a silica support. A saturated solution of copper (I) chloride in acetonitrile was sorbed into fumed silica (325 mVgram). The acetonitrile was then removed under reduced pressure. A solution of potassium chloride and lanthanum chloride 1n formic acid was added to the cuprous chloride coated silica. The formic acid was removed under reduced pressure to produce the layered oxyhydrochlorination catalyst. The weight composition of the final catalyst was 41.7% CuCI, 37.5% Si02, 11.5% KC1, and 9.4% LaClj. The catalyst could be activated in a stream of hydrogen chloride at 300°C for ten minutes. 

Semmelhack demonstrated that the addition of alkali metal chloride salts can sometimes markedly increase the yields of coupling products in heterogeneous Pd-catalyzed reactions, especially when the olefin component contains an amide function [15]. It has been claimed that palladium-grafted mesoporous material (MCM-41), designated Pd-TMSll, is one of the most active heterogeneous catalysts for the Heck reaction and enables C-C formation with activated and non-activated aryl substrates [16a,b]. Nanoscale particles of palladium clusters prepared by the ultrasonic reduction of Pd(OAc)2 and NR4X in THF or methanol, were also active for C-C couplings [17]. 

Potassium chromate is used as an indicator in titrations for the determination of chloride ion. At the end point of a titration of an aqueous solution of a metal chloride salt (e.g. NaCl) against silver nitrate solution in the presence of potassium chromate, red Ag2Cr04 precipitates. Give equations for the pertinent reactions occurring during the titration, and, using relevant data from Table 6.4, explain how the indicator works. 

Fig. 1.1 Electrosteric (i.e. electrostatic with the halide anions located between the positively charged NP surface and the tetra-N-butyl ammonium cations and steric with the tetra-N-butyl ammonium cation) stabilization of metal NPs obtained by reduction of a metal chloride salt in the presence of a tetra-N-butyl ammonium cation (Bonnemann-type synthesis of Eq. (1.1)). The presence of...

Another interesting piece of work is concerned with metal fcis(dithiolene) complexes substituted peripherally with four or eight aliphatic chains ((70) R = OCJ32 +i> R = H R = R = OC H2/,+i). Structurally similar to the metal /3-diketonate complexes discussed above, it was expected that such complexes would exhibit columnar mesophases on the basis of their disk-like shape. Furthermore, combined with their vr-acceptor properties, such discogens could find potential applications as low-dimensional conductors. The complexes were synthesized in a one-pot procedure the appropriately substituted benzoin or benzil (a-diketone derivative) was treated with P4S10, and complexation was carried out in situ with the metal chloride salt. 

In an open, randomized, crossover study in mixed breed dogs, 12mgkg norfloxacin in 0.01 M HCl was given alone or co-administered with equimolar amounts of a metal chloride salt. Differences in the Cmax and AUC were observed and found to follow the same rank order as the complex formation constants. A follow up study looking at the effect of five different doses of Mg + (0.25, 0.5, 1, 2 and 4 1 Mg + norfloxacin), from MgCl2, showed that increasing the available Mg + resulted in a rank order decrease in the oral absorption of norfloxacin, most likely because more of the active compound is tied up as the metal ion complex. 

Alkali metal chloride Salt concentration in the initial solution (M) Morphometric data Fraction of macropores (%) Average size of macropores ()tm)... 

Hydrolysis reactions of the chlorinated solvents with water occur at a very slow but finite rate [6]. The biggest problem is the presence of a separate water phase in contact with a metal surface and the solvent phase. The presence of the water phase encourages removal of small amounts of metal chloride salts formed by any metal-solvent reaction. The initial reaction sites are often sealed by the extremely small amounts of insoluble metal salt deposits. Removal of these insoluble and protective salt deposits into the water... 

The photoprocesses of ruthenium tris(4,7-diphenyl-l,10-phenanthrolinedi-sulfonate) (Ru(BPS)3" ) intercalated in a layered double hydroxide (LDH) has been studied (102). The compound was prepared by coprecipitation of Mg/Al LDH from an aqueous NaOH solution containing the metal chloride salts and Ru(BPS)3" with hydrothermal treatment. Multiexponential decay profiles were observed. From the effects of surface dilution by Zn(BPS)3" on luminescence, the decay profile has been attributed to self-quenching processes similar to those for [Ru(bpy)3] -smectite systems. 

This derivative forms stable complexes with the cations of alkali metal picrates (A a > 10 M for Na" ", K+, Rb", and Cs" ") in 4 1 CDCI3/CD3OD. Moreover, it can also solubilize and bind alkali metal chloride salts (K > 10 M )... 

The most common platinum precursors used for impregnation are chloride salts however, it has been argued that the metal chloride salts might lead to... 

Metallic chloride salts, such as ferric chloride and cupric chloride, can be very corrosive to CF8M. Above 160°F (71°C), chloride can also cause SCC. The combination of chlorides, water, oxygen, and surface tensile stress can result in cracking at stresses far below the tensile strength of all austenitic SSTs. Although a threshold chloride level may exist, one is difficult to set because chlorides concentrate in pits, crevices, and under deposits until the minimum concentration is reached. One must be concerned about SCC any time a few hundred ppm chlorides is present and the temperature exceeds about 160°F (71 °C). SCC may develop at lower temperatures if the pH is low. 

Figure 20 Evolution with time of the pH of synthetic solution made of metallic chloride salts [40],...

Na2Si03, Na4Si20s, gas phase reduction [11,15,19,21]. Generally, metal chloride salts (H2PtCl6, RuCls, NiCU, etc.) are used as metal precursors. As metal chloride salts may reduce the dispersion of nanoparticles (NPs) on support materials [21], a number of binary and ternary electrocatalysts have also been prepared by using chloride-free precursor salts such as carbonyl, nitrate, sulfite complexes, etc. [15,21]. NaBH4 and polyol reduction methods are repeatedly used [15,21-25]. Recently, the microwave assisted chemical reduction method has also been used to obtain better dispersion and reduce the particle sizes of metal catalysts [24-26]. 

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