Nickel® cyanide

The Sandmeyer reaction may also be applied to the preparation of nitriles. The solution of the diazonium salt is added to a solution of cuprous cyanide in excess of sodium or potassium cyanide solution (sometimes improved yields are obtained by substituting nickel cyanide for cuprous cyanide), for example CH3 CH, CH3... 

Alternatively, add 1 or 2 drops of 5 per cent, nickel nitrate solution to 2-3 ml. of the fusion solution, filter off the nickel cyanide and/or nickel sulphide, acidify the filtrate with 2N nitric acid, and test for hahdes as above. 

The first breakthrough came m 1911 when Richard Willstatter prepared cyclooc tatetraene by a lengthy degradation of pseudopelletienne a natural product obtained from the bark of the pomegranate tree Today cyclooctatetraene is prepared from acetylene m a reaction catalyzed by nickel cyanide... 

Cyanide Copper cyanide Nickel cyanide Potassium cyanide Silver cyanide Sodium cyanide Zinc cyanide... 

In addition to the tetrahedral and octahedral complexes mentioned above, there are two other types commonly found—the square planar and the linear. In the square planar complexes, the central atom has four near neighbors at the corners of a square. The coordination number is 4, the same number as in the tetrahedral complexes. An example of a square planar complex is the complex nickel cyanide anion, Ni(CN)4-2. 

Palladium complexes also catalyze the carbonylation of halides. Aryl (see 13-13), vinylic, benzylic, and allylic halides (especially iodides) can be converted to carboxylic esters with CO, an alcohol or alkoxide, and a palladium complex. Similar reactivity was reported with vinyl triflates. Use of an amine instead of the alcohol or alkoxide leads to an amide. Reaction with an amine, AJBN, CO, and a tetraalkyltin catalyst also leads to an amide. Similar reaction with an alcohol, under Xe irradiation, leads to the ester. Benzylic and allylic halides were converted to carboxylic acids electrocatalytically, with CO and a cobalt imine complex. Vinylic halides were similarly converted with CO and nickel cyanide, under phase-transfer conditions. ... 

When acetylene is heated with nickel cyanide, other Ni(II) or Ni(0) compounds, or... 

Nickel cyanide mixed with magnesium causes the incandescence of magnesium. It is a dangerous reaction, which is typicai of the cyanide ion in which the cation does not play a crucial role. 

Finally, when copper dicyanide is heated with magnesium, it caus the mixture to glow, as with nickel cyanide. 

Magnesium reacts with incandescence on heating with cadmium cyanide, cobalt cyanide, copper cyanide, lead cyanide, nickel cyanide and zinc cyanide. With gold... 

In another Reppe process, acetylene is reacted with formaldehyde to yield butyndiol, which can be converted to butadiene for the manufacture of the synthetic rubber Buna the catalyst is nickel cyanide ... 

Nickel-copper alloys, 73 518 77 100 Nickel cyanide, 77 112 Nickel dialkyldithiocarbamates, 77 124 Nickel dicycloalkyldithiophosphinates, 77 124... 

The phase-transfer catalysed reaction of nickel tetracarbonyl with sodium hydroxide under carbon monoxide produces the nickel carbonyl dianions, Ni,(CO) 2- and Ni6(CO)162, which convert allyl chloride into a mixture of but-3-enoic and but-2-enoic acids [18]. However, in view of the high toxicity of the volatile nickel tetracarbonyl, the use of the nickel cyanide as a precursor for the carbonyl complexes is preferred. Pretreatment of the cyanide with carbon monoxide under basic conditions is thought to produce the tricarbonylnickel cyanide anion [19], as the active metal catalyst. Reaction with allyl halides, in a manner analogous to that outlined for the preparation of the arylacetic acids, produces the butenoic acids (Table 8.7). 

Isomerism of the but-3-enoic acids into the E-but-2-enoic acids is base-catalysed (Table 8.8), whereas the formation of the other isomers indicates the participation of rt-allylnickel complexes in the reaction. Potassium nickel tetracarbonyl is a considerably poorer catalyst, compared with nickel cyanide, whereas nickel sulphate and nickel iodide are ineffective catalysts. 

The enantioselectivity increases dramatically when the ligands contain electron-withdrawing P-aryl substituents. Electron-donating substituents on the substrate give the highest ee (91% for 6-methoxy-2-vinylnaphthalene in apolar solvents). Mechanistic studies at room temperature have shown that at low concentration of HCN nickel zero species are the resting states, but at higher concentrations of HCN q3-benzyl nickel cyanide species were also observed. 

Allyl chlorides and bromides are readily carbonylated to unsaturated acids using nickel cyanide and phase transfer catalysis conditions. Mechanistic studies revealed that the key catalytic species in this reaction is the cyanotricarbonylnickelate ion(20). 

Nickel cyanide is used for nickel plating. It also is used to synthesize butadiene from acetylene. 

Nickel cyanide is prepared by treating a soluble nickel salt, such as nickel chloride or nickel sulfate, with potassium cyanide solution ... 

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