Tetrachloronickelate is the metal complex with the formula . Salts of the complex are available with a variety of cations, but a common one is tetraethylammonium.
When concentrated lithium chloride and nickel chloride solution in water is mixed, only a pentaaquachloro complex is formed: . However in other organic solvents, or molten salts the tetrachloronickelate ion can form. Nickel can be separated from such a solution in water or methanol, by partitioning it into a cyclohexane solution of amines.
Organic ammonium salts of the type (R3NH)2 are often thermochromic (R = Me, Et, Pr). Near room temperature, these salts are yellow , but these solids become blue when heated to near 70 °C. The bright blue color is characteristic of tetrahedral , the intensity being a consequence of the Laporte selection rule. The yellow color results from a polymer consisting of octahedral Ni centers. The corresponding tetrabromonickelates are also thermochromic with a lower transition temperatures.
History
The blue colour due to the tetrachloronickelate ion was first observed in 1944 when Remy and Meyer melted caesium chloride and caesium nickel trichloride together.
Compounds
formula | name | structure | Remarks | references |
---|---|---|---|---|
Cs2NiCl4 | caesium tetrachloronickelate | blue, stable only over 70° | ||
2NiCl4 | Tetramethylammonium tetrachloronickelate | dark blue | ||
2NiCl4 | Tetraethylammonium tetrachloronickelate | |||
2NiCl4 | 1,1,1-trimethylhydrazinium tetrachloronickelate | blue, only stable over 145 °C, under this is yellow | ||
2NiCl4 | bis-tetraphenylarsonium tetrachloronickelate | blue, melts at 199.5°C | ||
2NiCl4 | bis-triphenylmethylarsonium tetrachloronickelate | blue | ||
2NiCl4 | 1-ethyl-3-methylimidazolium tetrachloronickelate(II) | tetragonal I41/a a=14.112 c=19.436 V=3871.1 Z=8 density=1.47 MW=422.84 | melts at 92° | |
2NiCl4 | 1-butyl-3-methylimidazolium tetrachloronickelate(II) | dark blue, melts at 56°C | ||
2NiCl4 | 1-pentyl-3-methylimidazolium tetrachloronickelate(II) | dark blue liquid | ||
2NiCl4 | 1-hexyl-3-methylimidazolium tetrachloronickelate(II) | dark blue liquid | ||
2NiCl4 | 1-heptyl-3-methylimidazolium tetrachloronickelate(II) | dark blue liquid | ||
2NiCl4 | 1-octyl-3-methylimidazolium tetrachloronickelate(II) | dark blue liquid | ||
NiCl4 | ethylenediammonium tetrachloronickelate(II) | perovskite layered, space group P21/c a=8.441, b=6.995, c=6.943, β=92.925 Z=2 | brown, isostructural with Mn, Cu, Pd, and Cd compounds |
Related substances
References
- Naida S. Gill; F. B. Taylor (1967). "Tetrahalo Complexes of Dipositive Metals in the First Transition Series". Inorganic Syntheses. Vol. 9. pp. 136–142. doi:10.1002/9780470132401.ch37. ISBN 978-0-470-13240-1.
- Florence, T. M.; Farrar, Yvonne J. (July 1968). "Liquid-liquid extraction of nickel with long-chain amines from aqueous and nonaqueous halide media". Analytical Chemistry. 40 (8): 1200–1206. doi:10.1021/ac60264a010.
- Ferraro, John R.; Sheren, Anne T. (3 February 1978). "Some new thermochromic complexes of Nickel(II) of the type 2NiCl4". Inorganic Chemistry. 17 (9): 2498–2502. doi:10.1021/ic50187a032.
- ^ Gill, Naida S.; Nyholm, R. S. (1959). "802. Complex halides of the transition metals. Part I. Tetrahedral nickel complexes". Journal of the Chemical Society (Resumed): 3997. doi:10.1039/JR9590003997.
- ^ Cotton, F. A.; Faut, O. D.; Goodgame, D. M. L. (January 1961). "Preparation, Spectra and Electronic Structures of Tetrahedral Nickel(II) Complexes Containing Triphenylphosphine and Halide Ions as Ligands". Journal of the American Chemical Society. 83 (2): 344–351. doi:10.1021/ja01463a021.
- Inman, Guy W.; Hatfield, William E.; Jones, Edwin R. (August 1971). "The magnetic properties of tetraethylammonium tetrachloronickelate(II) and tetraethylammonium tetrabromonickelate(II)". Inorganic and Nuclear Chemistry Letters. 7 (8): 721–723. doi:10.1016/0020-1650(71)80078-8.
- Goedken, V. L.; Vallarino, L. M.; Quagliano, J. V. (December 1971). "Cationic ligands. Coordination of the 1,1,1-trimethylhydrazinium cation to nickel(II)". Inorganic Chemistry. 10 (12): 2682–2685. doi:10.1021/ic50106a011.
- ^ Meredith, M. Brett; McMillen, C. Heather; Goodman, Jonathan T.; Hanusa, Timothy P. (August 2009). "Ambient temperature imidazolium-based ionic liquids with tetrachloronickelate(II) anions". Polyhedron. 28 (12): 2355–2358. doi:10.1016/j.poly.2009.04.037.
- Hitchcock, Peter B.; Seddon, Kenneth R.; Welton, Thomas (1993). "Hydrogen-bond acceptor abilities of tetrachlorometalate(II) complexes in ionic liquids". Journal of the Chemical Society, Dalton Transactions (17): 2639. doi:10.1039/DT9930002639.
- Skaarup, Steen; Berg, Rolf Willestofte (September 1978). "Structural properties and vibrational spectra of the ethylene-diammonium family of perovskite layer-type crystals: , M = Ni, Pd, Cu, Cd, Mn". Journal of Solid State Chemistry. 26 (1): 59–67. Bibcode:1978JSSCh..26...59S. doi:10.1016/0022-4596(78)90133-0.
Nickel compounds | |
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Nickel(0) | |
Nickel(II) | |
Nickel(III) | |
Nickel(IV) |
Chlorine compounds | |
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Chlorides and acids | |
Chlorine fluorides | |
Chlorine oxides | |
Chlorine oxyfluorides | |
Chlorine(I) derivatives |