Copper sulfate, decomposition

Cmde diketene obtained from the dimeriza tion of ketene is dark brown and contains up to 10% higher ketene oligomers but can be used without further purification. In the cmde form, however, diketene has only limited stabHity. Therefore, especiaHy if it has to be stored for some time, the cmde diketene is distiHed to > 99.5% purity (124). The tarry distiHation residue, containing trike ten e (5) and other oligomers, tends to undergo violent Spontaneous decomposition and is neutralized immediately with water or a low alcohol. Ultrapure diketene (99.99%) can be obtained by crystallization (125,126). Diketene can be stabHized to some extent with agents such as alcohols and even smaH quantities of water [7732-18-5] (127), phenols, boron oxides, sulfur [7704-34-9] (128) and sulfate salts, eg, anhydrous copper sulfate [7758-98-7]. 

Fig. 72. Photometer curves of X-ray photographs taken during the decomposition process of copper sulfate pentahydrate...

Cyclopropanes are present in a variety of natural products and the intramolecular cyclopropanation sequence allows ready access to such compounds. The sesquiterpenoid antibiotic ( )-cycloeudesmol (53) was readily prepared from the monocyclic system (54 Scheme 9).91 Copper sulfate catalyzed decomposition of (54) generated the tricyclic system (55) with full control of stereochemistry. Further conversion of (55) to ( )-cycloeudesmol was achieved in four steps in 81% overall yield. A second example shown in equation (27)73 allowed access to (56), an important substructure of the antibiotic CC-1066. 

Chalcanthite is copper sulfate, often used as a poison, and sometimes as a pigment. Melanterite is a highly poisonous product of the decomposition of pyrite and marcasite. This white powdery material can often be found on deteriorating jewelry or other items made of iron sulfides. It is mentioned here because of its extreme toxicity. 

Aromatic diazonium salts on treatment with sodium nitrite decompose to form nitro compounds. This method represents a good procedure for obtaining o- and p-dinitrobenzenes, in 70% and 76% yield, respectively, from the corresponding diazonium sulfates. Improved yields in the preparation of dinitronaphthalenes are obtained when the decomposition of the diazonium sulfates is catalyzed by a cupro-cupri sulfite prepared by the interaction of copper sulfate and sodium nitrite. The procedure is illustrated by the synthesis of 1,4-dinitronaphthalene (60%). Occasionally, diazonium fluoborates are first formed, and these compounds are treated with sodium nitrite in the presence of copper powder, viz.,... 

The DSC, TG curves of solvates and hydrates are related to the phase diagrams between substance and solvent (or water). Eutectic are observed. Fusion or decomposition of the solvate may occur during heating. Therefore, one may observe the melting of the solvate followed by recrystallization into the anhydrous form or the endothermic desolvatation in the solid state. In certain cases both phenomena may over-lapp. Details about experimental factors and examples can be found in Ref. If the anhydrous form is metastable, further phase transitions follow the desolvatation. If several solvates or hydrates exist, the transitions observed depend on the pressure, as demonstrated by Soustelle in the case of copper sulfate pentahydrate. Depending on the pressure, the direct dehydration into the anhydrous or the dehydration via the monohydrate, or the three dehydration steps trihydrate, monohydrate and anhydrous forms may be obtained. Hydrates have been the subject of... 

Some phenylhydrazides are very resistant and there is decomposition and possibly some epimerization in the alkaline solutions on long boiling. It has been found that boiling with a solution of copper sulfate is an advantageous procedure. The following directions for preparing man-nonic lactone from mannonic phenylhydrazide illustrate the method. 

The cupro-cupri sulfite of this variety is more efiicient as a decomposition reagent than the red-violet precipitate obtained by treating a hot solution of copper sulfate with a solution of ammonium sififite saturated with sulfur dioxide and subsequently heating the mixture for 10 minutes at 90°. 

Smith, A. B., III. Vinylogous Wolff rearrangement. Copper sulfate-catalyzed decomposition of unsaturated diazomethyl ketones. J. Chem. Soc., Chem. Common. 1974, 695-696. 

During the earliest (1930) studies of the mechanisms of decomposition of solids. Gamer and Tanner [52] worked with copper sulfate pentahydrate. To simplify the interpretation of rate-time measurements, the surfaces of the prepared ciystals were initially activated (i.e. rapidly nucleated) by abrasion with product solid. Because... 

The scope of temperature- and time-resolved SCTGA has been revealed by Parkes, Barnes and Charsley, via studies of the decomposition of inorganic salts. Temperature-resolved SCTA is particularly useful for resolving the dehydration characteristics of copper sulfate pentahydrate. A typical linear heating (LH) TGA profile for this salt is shown in Fig. 10, and is compared with a proportional heating (PH) SCTGA profile over the same temperature range. 

The results of our evaluations for the other hybrid cycles are summarized in Table 3. The advantages of the Cu-Cl cycle are its low maximum temperature requirement and its relatively high efficiencies. The Level 1 and 2 efficiencies exceed 40% (LHV). All reactions in this cycle have been proven [1, 9, 10]. The Mg-Cl cycle has a low maximum temperature requirement but comparatively low Level 1 and 2 efficiencies. The chemistry for the thermal reactions has not been demonstrated. The low maximum temperatures, 550 and 600°C, respectively, for the two chloride cycles provide more flexibility in coupling them with heat sources other than the VHTGR. The advantages of the metal sulfate cycles are their lower corrosivity and the common high temperature decomposition reaction with the sulfur cycles. Of the two metal sulfate cycles, the copper sulfate cycle appears more promising because the copper sulfate cycle requires somewhat lower temperatures than the zinc sulfate cycle. The copper sulfate cycle has also been demonstrated with recycled materials, but no experimental work has been reported for the zinc sulfate cycle [1]. 

An interesting enhancement of the cupric ion catalysis by manganous ion has been reported by Bobtelsky (97). It was found that in neutral solution with 0.05 N manganous sulfate the rate of decomposition increases with increase of copper sulfate but passes through a maximum at about 0.05 N. Here the rate is about ten times that of copper sulfate alone. Zinc and cadmium sulfates are also reported to enhance the Cu++-Mn++ catalysis. 

Mobile chlorine attached to a heterocycle often reacts also with hydrazine and decomposition of the resulting hydrazine derivative by aqueous copper sulfate solution gives a product in which the original halogen has been replaced by hydrogen.441... 

Decomposition of jS,7-unsaturated diazoketones of type (1) with copper sulfate in methanol proceeds by a skeletal rearrangement to 7,6-unsaturated esters (2) ... 

It was reported in the literature and also demonstrated in this laboratory that both Co304 and copper chromite are poisoned by sulfur. This results from the accumulation of sulfate groups on the catalyst surface. The base metal sulfates and aluminum sulfate are very stable, and they decomposed to the oxide only at temperatures above 650°C (see Table IV and Figure 2). Above 650°C, activity was restored because of sulfate decomposition. When a base metal catalyst was subjected to high temperatures before being cooled down for a CVS test, it had good activity for a short period of time which was dependent on the sulfur content of the gasoline and the surface areas of the washcoat and base metal catalyst. 

CHEMICAL PROPERTIES stable in air stable under ordinary conditions of use and storage hazardous polymerization will not occur hydrolyzes to glucose and fructose by dilute acids and by invertase, a yeast enzyme optical rotation falls and is negative upon completion of hydrolysis does not reduce Fehling s solution (consists of two solutions, one of copper sulfate, the other of alkaline tartrate), forms an osazone, or show mutarotation fermentable, but resists bacterial decomposition when in high concentrations. FP (NA) LFL/UFL (NA) AT (NA) MEC (45g/cm ). 

Silva and coworkers [120] reported the thermal characterization of double sulfites witii empirical formula Cu2S03-MS03 2H20 (where M is Cu, Fe, Mn, or Cd), obtained by saturation with sulfur dioxide gas of an aqueous mixture of M(n)-sulfate and copper sulfate at room temperature. The thermal behaviour of the double sulfites, evaluated by TG and DSC, showed that these salts are thermally stable up to 200 C, but the structures of sulfite ion coordination strongly influence the course of the thermal decomposition. The sulfite species coordinated to the metal through the oxygen was more easily oxidized to sulfate than the sulfur-coordinated species. 

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