Patent GB-714202-A (GB)
Title: Complex metal cyanides
IPC: C01C3/11
Filed: 1952-04-10
Abstract: Complex metal cyanides are obtained by bringing together in a liquid medium a complex alkali metal or ammonium cyanide containing a heavy metal in the anion and a complex metal salt containing in the cation a heavy metal in combination with an organic phosphino or amino radical.  The complex metal cyanides are stated to have the general formula:  [A]xMe1.Me2(CN)4 wherein A represents an amine or organic phosphine radical, Me1 and Me2 are atoms of heavy metals which may be the same or different metals and x is 1 or 2.  The invention also comprises as new products complex cyanides of the above formula wherein at least one of the metals Me1 and Me2 is nickel.  The complex alkali metal or ammonium cyanides may be e.g. the complex potassium, sodium or ammonium cyanides of nickel, cobalt, iron, copper, zinc or silver, e.g. potassium nickel cyanide, ammonium or potassium copper cyanide, or potassium iron cyanide.  Starting materials of the other kind are e.g. such complex salts as may be obtained by treating salts of nickel, cobalt, copper or other heavy metals capable of forming complex compounds with organic phosphino or amino compounds, e.g. those prepared from nickel halides, cyanide, thiocyanate, or carboxylic acid salt of nickel and triaryl phosphines such as triphenyl or tritolyl phosphine, trialkyl phosphines, heterocyclic nitrogen compounds such as pyridine or piperidine or their homologues, primary, secondary, or tertiary aromatic amines or aliphatic, cycloaliphatic or araliphatic amino compounds.  The reaction may be carried out by adding to a solution of the one complex compound in water, alcohols, glycol monoethers, dioxane, lactones or other suitable solvent a solution of the other complex compound in the same or another solvent.  In some cases the reaction is accelerated by gentle heating or boiling under reflux.  Instead of using a ready-made complex compound the latter may be formed in situ, e.g. instead of a triaryl phosphine nickel halide a mixture of a triaryl phosphine and a nickel halide may be used.  The complex products are stated to be useful as catalysts in the reactions where olefins or acetylenes are subjected to cyclization or carboxylation. In examples, (1) an aqueous solution of potassium nickel cyanide K2[Ni(CN)4] is added to a methanol solution of triphenyl phosphine nickel chloride at 40-50 DEG  C. to yield the complex compound [(C6H5)3P]2Ni2(CN)4; (2) an aqueous solution of potassium copper cyanide K3[Cu(CN)4] is added to a methanol solution of triphenyl phosphine and nickel chloride NiCl26H2O at 40 DEG  to 46 DEG  C. to yield a compound containing nickel and copper in the atomic ratio of 3 : 2; (3) an aqueous solution of nickel bromide is added to a solution of pyridine in methanol and an aqueous solution of potassium nickel cyanide then added to yield the compound (C5H5N)2Ni2(CN)4, methyl ethyl pyridine or piperidine may be used instead of pyridine to give the corresponding compounds and the acetic or chloracetic acid salt of nickel may be used instead of nickel bromide; (4) N,N-dimethyl aniline is added to copper chloride dissolved in ethanol and an aqueous solution of potassium nickel cyanide is then added at 50 DEG  C. to yield the compound [(C6H5)(CH3)2N] CuNi(CN)4; (5) a solution of aniline in butyrolactone is mixed with an aqueous solution of nickel bromide and an aqueous solution of potassium p nickel cyanide then added at 100 DEG  C. to yield the compound [(C6H5)NH2]2Ni2(CN)4; (6) a solution of copper chloride is added to a solution of triethylamine in butyrolactone and after heating to 100 DEG  C. an aqueous solution of potassium nickel cyanide is added to yield the compound [(C2H5)3N]CuNi(CN)4; (7) a mixture of triphenyl phosphine, methanol, and an aqueous solution of nickel bromide is boiled under reflux and an aqueous solution of potassium zinc cyanide then added to yield the complex compound [(C6H5)3P]2NiZn(CN)4; (8) a mixture of triphenyl phosphine, methanol, zinc chloride, and water is boiled under reflux and an aqueous solution of potassium nickel cyanide then added and the mixture heated to boiling to yield the compound [(C6H5)3P] ZnNi(CN).