Nickel, tetracyano

Nickel, methyltetrakis(trimethylphosphine)-tetraphenylborate stereochemistry, 1,44 Nickel, pentacyano-isomerism, 1, 206 structure, 1, 40 Nickel, tetracarbonyl-cxchangc reactions, 1,288 Nickel, tetracyano-, 5,67 Nickel, tetrahalo-, 5, 186 Nickel, tetrakis(dinitrogen)-syn thesis... 

E. Miscellaneous methods. Exchange reactions between the tetracyano-nickelate(II) ion [Ni(CN)4]2 (the potassium salt is readily prepared) and the element to be determined, whereby nickel ions are set free, have a limited application. Thus silver and gold, which themselves cannot be titrated complexometrically, can be determined in this way. 

N7NiC22H2i, Nickel(II), (1,2,6,7-tetracyano-3,5-diimino-3,5-dihydropyrrolizinido)-(dipivaloyhnethanido)-, 34 75... 

The tetracyano-complexes of all three metals are square-planar and very similar, corresponding salts being isomorphous. Coordinate analyses have recently been given in D symmetry for the nickel (154) and for the platinum complexes (243). 

Bulk crystalline radical ion salts and electron donor-electron acceptor charge transfer complexes have been shown to have room temperature d.c. conductivities up to 500 Scm-1 [457, 720, 721]. Tetrathiafiilvalene (TTF), tetraselenoful-valene (TST), and bis-ethyldithiotetrathiafulvalene (BEDT-TTF) have been the most commonly used electron donors, while tetracyano p-quinodimethane (TCNQ) and nickel 4,5-dimercapto-l,3-dithiol-2-thione Ni(dmit)2 have been the most commonly utilized electron acceptors (see Table 8). Metallic behavior in charge transfer complexes is believed to originate in the facile electron movements in the partially filled bands and in the interaction of the electrons with the vibrations of the atomic lattice (phonons). Lowering the temperature causes fewer lattice vibrations and increases the intermolecular orbital overlap and, hence, the conductivity. The good correlation obtained between the position of the maximum of the charge transfer absorption band (proportional to... 

K2[Fe(NO)2(CN)2]. My former co-worker R. Nast (83) showed that the reaction of carbon monoxide with K4[Ni2I(CN)6] and K4[Ni°(CN)4] in liquid ammonia gave nickel cyanocarbonyl complexes with monovalent and zero-valent metal atoms. The isoelectronic hexacyanoiron(III) or tetra-cyanonickel(II) complexes correspond to the cyanocarbonyls [Feu(CN)5 CO]3-, [Ni (CN)3CO]2-, or [Ni°(CN)2(CO)2]2-. Cobalt is analogous to nickel in forming the complex [Co(CN)3CO]2-. According to our earlier work, [Fe"(CN)5CO]3- and [Fem(CN)6]3- are isosteric (87). Other structural investigations were concerned with tetracyano and tetracarbonyl complexes (88). 

Indirect determinations of several types can be carried out. Sulfate has been determined by adding an excess of standard barium(II) solution and back-titrating the excess. By titrating the cations in moderately soluble precipitates, other ions can be determined indirectly. Thus sodium has been determined by titration of zinc in sodium zinc uranyl acetate, and phosphate by determination of magnesium in magnesium ammonium phosphate. Quantitative formation of tetracyano nickel-ate(II) has been used for the indirect determination of cyanide. ... 

Q-(p-Toluenesulfonyloxyiinino)malononitrile (104), when treated with malono-nitrile in basic conditions, has been shown to give salts of l,l,3,3-tetracyano-2-azapropenide (105), which with concentrated sulfuric acid in methanol gave 2-amino-3,5-dicyano-6-methoxypyrazine (106) (484) and with hydrochloric acid in acetone gave 2-amino-6-chloro-3,5-dicyanopyrazine (485, 486). Catalytic cyclization of 2-(2 -aminobutylamino)butanol with Raney nickel has been found to give a mixture of 2,5-diethylpiperazine (25% yield) and 2,5-diethylpyrazine (8%) (487). 

Ballhausen CJ, Bjerrum N, Dingle R, Eriks K, Hare CR (1965) Polarized spectra of tetracyano nickelate crystals. Inorg Chem 4 514... 

Between 60 and 70 ml. of dry ammonia is then condensed in the reaction chamber by cooling the latter with a Dry Ice-Cellosolve bath. The potassium tetracyano-nickelate(II) is added by rotation of the appropriate sampling bulb, and the magnetic stirrer is started. The salt dissolves readily to form a yellow solution. The metallic potassium is then added. A bright red precipitate... 

Niccolates(II), hexafluoro-, 186 Niccolates(II), tetracyano-, 67 Niccolates(II), tetrahalogeno-, 186 Niccolates(II), trihalogeno-, 186 Nickel... 

Platinates, bis(oxalato)-, 139 cadmium complexes superstructure, 142 cobalt complexes, 140 electrical conductivity, 14] superstructure, 141 thermopower, 141 divalent cation salts, 140 iron complexes structure, 142 lead complexes superstructure, 142 magnesium complexes, 140 electrical conduction, 142 structure, 142 thermopower, 142 modulated superstructure, 139 monovalent cation salts, 139 nickel complexes structure, 141 partially oxidized, 139 Platinates, tetracyano-, 136 anion-deficient salts, 136 electrical conduction, 138 optical properties, 138 cation-deficient salts, 138 oxidation states, 136 partially oxidized, 138 semiconductors, 134 Platinum colloidal... 

Nishikiori. S. Takahashi-Ebisudani. Y. Iwamoto, T. Novel series of clathrate compounds of the three-dimensional metal complex hosts (yV-methyl-l,3-diaminopropane) cad-mium(II) tetracyanonickelate(II), (V,V-dimethyl-1,3-diaminopropane) cadmium(II) tetracyanonickelate(II) and (2-hydroxyethylinethylamine) cadmium(II) tetracyano-nickelate(II). J. Inclusion Phenom. Mol. Recognit. Chem. 1990, 9(2), 101-112. 

THE CRYSTAL STRUCTURES OF a, co-DIAMINOALKANECADMIUM(II) TETRACYANO-NICKELATE(II)-AROMATIC MOLECULE INCLUSION COMPOUNDS. I. 1,4-DIAMINO-BUTANE CADMIUM( I I) TETRACYANONICKELATE(II)-2,5-XYLIDINE (1/1) ... 

Z)-Alk-2-enenitriles are also available from the hydrocyanation of acetylenes, which occurs with cis stereospecificity when catalysed by a nickel(O) complex, and from the stereoselective cyanation of vinyl halides, catalysed by tetracyano-cobaltate(i). The latter procedure is equally applicable to the stereoselective synthesis of the corresponding ( )-isomers. Also, the ( )- and (Z)-isomers (17) and (18) react with piperidine with retention of configuration to provide (19) and (20) respectively (Scheme 30). In contrast, the corresponding reaction with sodium methoxide gives rise to the (Z)-isomer only. 

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