Cyanamide CAS

Calcium Cyanamide. ]CAS 156-62-7). CaCN-. white solid, funned (11 by heating cyanamide or urea with calcium oxide, sublimes at 1.05(1 C. (2) by heating calcium carbide at 1.100-I.200 C in a current of nitrogen. Decomposes in water with evolution of NFL. 

Dormancy breaking Ammonium nitrate Ca-cyanamide Ca-Nitrate... 

Lead chromate (VI) oxide Lead chromate, red. See Lead chromate oxide Lead cyanamide CAS 35112-70-0... 

EC microc q)sules were linked onto cotton via grafting with 1,2,3,4-butanetetracarboxylic acid (BTCA). The mercerized cotton was immersed in treatment baths with different concentrations of EC microcapsules and BTCA for reduction of curing temperature the catalysts cyanamide (CA) and N,N -dicyclohexylcarbodiimide... 

The two main producers of xanthates ia the United States, ie, American Cyanamid and Dow, shut down their plants ia the 1970s. American Cyanamid transferred its production to Canada, and siace thea has shut dowa that plant. Xanthates ia solutioa are available ia some areas of the United States and Canada and are transported locally by tmck. The U.S. consumption of xanthates for froth flotation was ca 1,812 t/yr ia 1985 (85). la the previously aoa-Soviet bloc the 1995 xanthate usage was estimated at 30,000 metric tons, and ia China and Russia at 25,000 metric tons, for a worldwide total of 55,000 metric tons. The estimated current number of xanthate plants ia the world is 14—16, with oae ia the United States and one ia Canada. 

For the manufacture of calcium cyanamide, cmde calcium carbide (ca 3.36 x 1.68 mm or 6 x 12 mesh) can be used, whereas for cyanamide and dicyandiamide, a 74 p.m (200 mesh) anhydrous carbide is used. 

Formula CaCN2 MW 80.11 cyanamide ion is linear and structurally similar to CO2 Structure N = CN = Ca Synonyms calcium carbimide lime nitrogen nitrolime... 

Elemental composition Ca 50.03%, C 14.99%, N 34.98. A measured amount of the compound is hydrolyzed with water. The product CaCOs is filtered, dried and determined by gravimetry. Calcium carbonate or the parent calcium cyanamide may be digested with nitric acid, diluted appropriately, and analyzed for Ca by AA or ICP spectroscopy. The hydrolysis product in solution, ammonia, may be measured by ammonium ion selective electrode, or by colorimetry followed by Nesslerization. 

C1C(=NH)NH2.HN03 mw 141.52, OB -11.3% colorless crysts, mp 120 expl at higher temp soly in w 7.9% at 0° and 22.2% at 30°. Prepd by treating cyanamide dihydro-chloride in w with aq AM or from tech Ca cyanamide (Ref 2), also by adding cooled coned nitric acid to very cold cyanamide in HCl (Ref 3)... 

CA 43, 5416(1949) (Improved process for the prepn of GuN from Amm thiocyanate and AN. As the direct fusion of these two substances produces an expin, the new process calls for dissolving the first in liq ammonia, and then heating with AN at 120° in a closed vessel to produce GuN, ammonia and hydrogen sulfide) 9) Cyanamid s Nitrogen Chemical Digest, Vol IV, Chemistry of Guanidine , American Cyanamid Co, NV(1950)... 

Nitrogen (ca. 5 at. %) occurs as carbon-nitrogen bonds, probably mainly cyanamide (NCN ), although other C-N bonded compounds were also believed to be present. If cyanamide is present as the Cd salt, this would tie up 5% of the Cd. The Cd S ratio was found to be only slightly higher than unity (ca. 1.02), and some of the Cd may be bound to carbonate. Therefore other C-N species are likely also to be present, e.g., cyanide, several of which could adsorb to one Cd or even to a CdS moiety. By reducing the concentration of thiourea in the bath, C-N impurities in the CdS film could be reduced almost to zero [77]. Whatever the nature of the C-N impurity, much of it could be removed simply by dissolution in water at 60°C [78]... 

It should be pointed out that this deposition was carried out for films ca. 50 nm thick the study was carried out with CdS window layers for solar cells in mind, which are usually thin. It is possible that much longer depositions result in different impurities. Thus the sparingly soluble cadmium carbonate and cyanamide will be converted to CdS if enough sulphide ion is formed with time (or, for the complex-decomposition mechanism, if enough adsorbed thiourea decomposes on the surface of the solid phases). Of course, longer time also means more thiourea decomposition products. 

The presence of cyanamides of Cd and Pb in films of (Cd,Pb)S was confirmed by thermal desorption mass spectrometry [23]. Cyanamide (H2CN2) is a product of the decomposition of thiourea and forms sparingly soluble metal salts. The metal cyanamide content of the film varied from ca. 5% up to ca. 20% (by weight). The presence of the cyanamides decreased the intensity of the XRD reflections, presumably due to poorer crystallization of the sulphides. Interestingly, the photosensitivity of the films increased with higher metal cyanamide content, although whether this was due specifically to the presence of the cyanamide or to its effect on the crystal growth was not known. 

The same group also deposited (Cd,Pb)S using a flow system [24]. In this case, metal cyanamides were not detected by XRD, presumably because the flow system removed the cyanamide. The rate of flow affected the crystal size Larger flow rate resulted in finer-grained deposits. Elemental analysis and XRD showed the incorporation of Cd in the films, again up to ca. 10%, as a solid solution. 

Urea, melamine, cyanamide, dicyandiamide, and guanidine react at elevated temperatures with sulfur tetrafluoride to give (trifluoromethyl)iminosulfur difluoride (7) in 6-25% yield.172 In the presence of sodium fluoride at 25"C, urea is converted into fluorocarbonyliminosulfur difluoride (8), but at 50°C thiazyl fluoride (9) is the main product, both formed in ca. 60% yield. At higher temperatures, carbonyl difluoride (carbonic difluoride) and sulfur hexafluoride are the sole products of the reaction of urea with sulfur tetrafluoride.173... 

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