Interaction between zinc chloride

Figure 6. Interaction between zinc chloride or calcium chloride and epoxidized soya-bean oil at 180°C...

Cobalt has been demonstrated to induce seminiferous tubule damage and degeneration (vacuole formation, sloughing of cells, giant cell formation) in the testes of mice following exposure for 13 weeks (Anderson et al. 1993). Coadministration of cobalt and zinc chloride in the drinking water resulted in complete or partial protection in 90% of the animals. The sites of competitive interaction between zinc an cobalt were not established in the study however, the authors postulated that the mechanism(s) may be similar to those involved in prevention of cadmium toxicity by zinc. 

Feitknecht has examined the corrosion products of zinc in sodium chloride solutions in detail. The compound on the inactive areas was found to be mainly zinc oxide. When the concentration of sodium chloride was greater than 0-1 M, basic zinc chlorides were found on the corroded parts. At lower concentrations a loose powdery form of a crystalline zinc hydroxide appeared. A close examination of the corroded areas revealed craters which appeared to contain alternate layers and concentric rings of basic chlorides and hydroxides. Two basic zinc chlorides were identified, namely 6Zn(OH)2 -ZnClj and 4Zn(OH)2 ZnCl. These basic salts, and the crystalline zinc hydroxides, were found to have layer structures similar in general to the layer structure attributed to the basic zinc carbonate which forms dense adherent films and appears to play such an important role in the corrosion resistance of zinc against the atmosphere. The presence of different reaction products in the actual corroded areas leads to the view that, in addition to action between the major anodic and cathodic areas as a whole, there is also a local interaction between smaller anodic and cathodic elements. 

Kaushansky P.,Yariv S. The interactions between calcite particles and aqueous solutions of magnesium, barium or zinc chloride, Appl Goechem 1986 1 607-618. 

The conformation is proved by a significant NOE between the aldimine proton and the anomeric proton [17,24]. In polar solvents, free cyanide attacks the complex A, preferably from the unshielded Si-side. In unpolar solvents like chloroform, cyanide is not set free from the silyl derivative. The activation of the cyanide proceeds by an interaction between the exo chloride of the zinc complex and the silyl group. Thus, the cyanide is directed to the Re-side of the glycosyl imine (see Scheme 8). This nucleophilic attack produces L-aminonitriles with moderate or good stereoselectivity (S R 3-9 1) and high yields. 

It has been shown that when zinc and sulphuric acid interact (i) a new compound is formed, and (2) a definite weight relation exists between..the zinc and hydrogen. It is possible, though not so convenient, to prove that similar relations exist between the factors and products when sodium chloride and sulphuric acid interact. Hydrochloric acid gas is not so easily collected as hydrogen furthermore, the chemical action between sodium chloride and sulphuric acid is not always complete. However,... 

The condensation of acetone with D-ribose, with sulfuric acid as the catalyst, has also been examined in detail.17 The major component is 2,3-O-isopropylidene-D-ribofuranose (59%), together with three minor components l,5-anhydro-2,3-0-isopropylidene-D-ribofuranose (9%), 1,2 3,4-di-O-isopropylidene-a-D-ribopyranose (3%), and 1,2-0-isopropylidene-a-D-ribofuranose (6%). The authors observed that the only marked difference when other catalysts (such as copper sulfate or zinc chloride) were used was the absence of the anhydro compounds. Assuming that the 1-hydroxyl group is equatorial, the preponderance of the 2,3-acetal is consistent with the thermodynamic stability of the isomer having the least number of endo substituents and with the unfavorable interactions between the acetal rings in the 1,2 3,4-diacetal, which possesses a cis-syn-cis arrangement of rings.10... 

The. yj/t-sclcctivc reduction with DIBAL-H and zinc(II) chloride is exemplified in Table 12. These reactions presumably occur under chelation control via hydride delivery to the less hindered face of an intermediate such as 5. However, the fact that the combination of sodium borohydride and zinc(II) chloride reacts unselectively has prompted the suggestion that a specific interaction between intermediate 5 and DJBAL-H may also be involved137. Zinc(ll) chloride is not required in stoichiometric amounts (Table 12), although the selectivity may be unsatisfactory if loo little is employed137. 

On the other hand, in the case of zinc coatings on iron, zinc usually is anodic with respect to the substrate. If the corrosion products are the result of the interaction between the anodic and the cathodic products, as the anodic area (zinc) and cathodic area (iron) are separated, the corrosion products are formed within the solution and do not hinder the electrode processes. This is the case, for example, in the formation of zinc hydrate in aerated solutions of sodium chloride. The cathodic process that occurs on the iron supports the anodic dissolution of zinc and lead quickly to the increase in the size of the defects. If the corrosion problem was the rate of penetration into the substrate, the coating would be safe but of short duration. 

The reactions are complex and one can assume, as expressed inTM 3-215, a primary reaction between aluminum and HC followed a metathetical reaction of aluminum chloride with zinc o de leading to aluminum oxide and zinc chloride. Another way of hypothesizing on the sequence of events is the assumption of a primary thermitic reaction of aluminum and zinc oxide followed by interaction of the liberated zinc with the HC. In either case, the end result remains the same ... 

The chiral phosphonates 31a,e, possessing optically active BINOL as an auxiliary, also demonstrated their ability as asymmetric inducers in the dissymmetrization of carbonyl compounds. In order to achieve both high enantioselectivity and good chemical yield, addition of zinc chloride was quite effective in these transformations [8]. It is known that bicydo[3.3.0]octane derivatives usually adopt either W-, S-, or V-shaped conformations, and the observed stereochemistry of the alkene 92a was best explained by considering an initial approach of the nucleophile to the W-shaped bicyclo[3.3.0]octanone in the direction in which steric interaction between the reagent and the substrate is minimized. 

Christov calculated the parameters in the Pitzer ion interaction model from isopiestie measurements at 298.15 K by Ojkova and Staneva [890JK/STA]. This reference contains (interpolated) osmotic coefficients of zinc, magnesium, cobalt, and nickel selenate solutions from 0.1 mol-kg to saturated solution. Sodium chloride standards were used and the agreement between duplicate determinations was 0.2% or better. 

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