The oxalatonickelates are a class of compounds that contain nickelcomplexed by oxalategroups. They form a series of double salts, and include clusters with multiple nickel atoms. Since oxalate functions as a bidentate ligand it can satisfy two coordinate positions around the nickel atom, or it can bridge two nickel atoms together.
The shape around the nickel atom is octahedral for diaquabis(oxalato)nickelate. The colour of this is green due to the Ni(–O–)6chromophore. The absorption in infrared is at 8,300 9,060 13,400, 15,260, and 26,160 cm−1.[1] The ligand field parameters are 10 Dq=8800 cm−1 and B=1000 cm−1.[1]
Because the Ni2+ion resembles many other divalent metal ions, it can be substituted by them, or substitute for them in other oxalate compounds to form mixed oxalates where the proportions can vary continuously. For example, magnesium nickel oxalate dihydrate.[13]
References
^ abMorrison, J.T.; Baker, W.A. (January 1969). "Nickel(II) complexes with oxygen and sulfur donors". Inorganica Chimica Acta. 3: 463–467. doi:10.1016/S0020-1693(00)92534-9.
^Saha, H.L.; Mitra, S. (June 1987). "Thermal decomposition reactions of metal carboxylato complexes in the solid state. III. Thermographic and differential thermal studies of metal oxalato, malonato and succinato complexes". Thermochimica Acta. 116: 53–64. doi:10.1016/0040-6031(87)88164-9.
^Saha, H.L.; Mitra, S. (January 1987). "Thermal decomposition reactions of metal carboxylato complexes in the solid state. I. Thermographic and differential thermal studies of metal oxalato, malonato and succinato complexes". Thermochimica Acta. 109 (2): 331–342. doi:10.1016/0040-6031(87)80029-1.
^Saha, H.L.; Mitra, S. (March 1987). "Thermal decomposition reactions of metal carboxylato complexes in the solid state. II. Thermographic and differential thermal studies of metal oxalato, malonato and succinato complexes". Thermochimica Acta. 112 (2): 275–287. doi:10.1016/0040-6031(87)88284-9.
^ abDeb, Nidhuban; Baruah, S. D.; Dass, N. N. (2000). "Synthesis, Characterization and Thermal Decomposition of ( and )". Journal of Thermal Analysis and Calorimetry. 59 (3): 791–797. doi:10.1023/A:1010153720786. S2CID94453246.
^Deb, Nidhuban (July 2005). "Thermal decomposition of manganese(II)bis(oxalato)nickelate(II)tetrahydrate". Journal of Thermal Analysis and Calorimetry. 81 (1): 61–65. doi:10.1007/s10973-005-0746-y. S2CID94799986.
^Packter, A.; Omomo, A. (1984). "The coprecipitation of Magnesium Nickel Oxalate Dihydrate Powders (solid solutions) from aqueous solution: Precipitate compositions and Coprecipitate Mechanisms". Crystal Research and Technology. 19 (4): 467–476. Bibcode:1984CryRT..19..467P. doi:10.1002/crat.2170190406.