Copper -thiocyanate CuSCN

Determination as copper (I) thiocyanate, CuSCN. The solution (100 mL) should be neutral or slightly acid (hydrochloric or sulphuric acid), and contain not more than 0.1 g SCN . It is saturated with sulphur dioxide in the cold (or 50 mL of freshly prepared saturated sulphurous acid solution added), and then treated dropwise and with constant stirring with about 60 mL of 0.1M copper sulphate solution. The mixture is again saturated with sulphur dioxide (or 10 mL of... 

Cadmium carbonate CdCOj 1.0 io- Copper(l) thiocyanate CuSCN 1.77. 10-55... 

Copper(l) thiocyanate CuSCN 1111-67-7 121.630 wh-yel amorp powder 1084 2.86 iHjO, dil acid, EtOH, ace s eth ... 

Cadmium carbonate CdC03 1.0 10- Copper(I) thiocyanate CuSCN 1.77 10- ... 

The precipitate, collected in a sintered-glass (porosity No. 4) or porcelain filtering crucible, may be weighed more rapidly as follows. Wash the copper(I) thiocyanate five or six times with ethanol, followed by a similar treatment with small volumes of anhydrous diethyl ether, then suck the precipitate dry at the pump for 10 minutes, wipe the outside of the crucible with a clean linen cloth and leave it in a vacuum desiccator for 10 minutes. Weigh as CuSCN. 

Cul and CuSCN. Both Cul and CuSCN require copper in the monovalent state. This was achieved by complexing Cu2+ ions with thiosulfate, which also reduces Cu2+ to Cu+. Potassium iodide or thiocyanate served as an... 

Copper (Cu, at. mass 63.54) occurs in its compounds in the n, and less often in the I, oxidation state. The properties of copper(I) are similar to those of Ag, Au(I), and T1(I). Copper(I) forms sparingly soluble compounds with the halogens. In solution, copper(I) exists only in complexes, e.g., Cu(CN)2", CuCb", and Cu(NH3)2. Cupric hydroxide, Cu(OH)2, begins to precipitate at pH 5 and shows no amphoteric properties. Copper(II) forms ammine, chloride, tartrate, and EDTA complexes. As a result of oxidizing properties of Cu(ll), its cyanide complex is converted into copper(I) cyanide complex, and sparingly-soluble CuSCN is precipitated from Cu(II) thiocyanate. 

For introduction of SCN into aromatic compounds the Sandmeyer reaction or its Gattermann variant is much more widely applicable than direct replacement of H by SCN (see page 202). An aqueous thiocyanate solution and CuSCN are added to a diazonium salt solution prepared in the usual way, or the addition is made gradually in the reverse direction — the diazonium salt to an aqueous solution of K3[Cu(SCN)4] copper powder can also be used.1264-1266 Reaction, with evolution of nitrogen, often occurs at room temperature or on... 

Thiocyanate precipitates white CuSCN from Cu solutions not too strongly acidic. Its solubility is 2 pM at 18 °C, and it is formed by SO2 for the reduction and complete precipitation of copper even from Cu . 

H2SO3 (sulphurous acid) reduces Cu to Cu which can be precipitated as CuSCN by adding ammonium thiocyanate solution. The essential experimental conditions are slight acidity of the solution since copper(l) thiocyanate dissolves on decreasing the pH the presence of a reductant to reduce Cu to Cu", a slight excess of the precipitant, since a large excess increases the solubility of Cu thiocyanate. 

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