Nitratoauric acid
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| Names | |
|---|---|
| IUPAC name
Hydrogen tetranitratoaurate(III)[1]
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Other names
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| Identifiers | |
| ChemSpider | |
| EC Number |
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PubChem CID
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| Properties | |
| HAu(NO3)4 | |
| Molar mass | 445.99 g/mol (anhydrous) 500.04 g/mol (trihydrate) |
| Appearance | Brown Crystals[1] |
| Density | 2.84 g/cm3[1] |
| Melting point | 72.6 °C (162.7 °F; 345.8 K)[2] |
| Hydrolyzes[2] | |
| Solubility in nitric acid | Insoluble (0 °C) Soluble (30 °C) |
| Structure[2] | |
| Monoclinic | |
| C2/c | |
a = 1214.5 pm, b = 854.4 pm, c = 1225.7 pm
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| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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Oxidizing |
| GHS labelling: | |
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| Danger | |
| H272, H302, H312, H315, H318, H332, H335 | |
| P210, P220, P221, P261, P280, P302+P352, P304+P340, P305+P351+P338, P332+P313 | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
Other anions
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Chloroauric acid |
Other cations
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Potassium tetranitratoaurate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Nitratoauric acid, hydrogen tetranitratoaurate, or simply called gold(III) nitrate is a crystalline gold compound that forms the trihydrate, HAu(NO3)4·3H2O or more correctly H5O2Au(NO3)4·H2O.[3][2] This compound is an intermediate in the process of extracting gold.[4] In older literature it is also known as aurinitric acid.[5]
Preparation and reactions
[edit]Nitratoauric acid is prepared by the reaction of gold(III) hydroxide and concentrated nitric acid at 100 °C:[2][5]
- Au(OH)3 + 4HNO3 → HAu(NO3)4 + 3 H2O
This compound reacts with potassium nitrate to form potassium tetranitratoaurate at 0 °C:[6]
- HAu(NO3)4 + KNO3 → KAu(NO3)4 + HNO3
Properties
[edit]Nitratoauric acid trihydrate decomposes to the monohydrate at 72 °C. If continually heated to 203 °C, it decomposes to auric oxide.[2]
Simple gold(III) nitrate
[edit]The production of the simple nitrate (Au(NO3)3) was reported from the reaction of gold oxide and dinitrogen pentoxide, however, this was later proven to be nitronium tetranitratoaurate ((NO2)Au(NO3)4).[7][8]
However, the ammine complex of the simple gold nitrate is known. Au(NH3)4(NO3)3, also known as tetraaminegold(III) nitrate, is produced by the addition of ammonium nitrate to a solution of chloroauric acid. The hydrolysis of this compound produces fulminating gold.[9][10][11]
References
[edit]- ^ a b c "Gold Nitrate". ESPI Metals.
- ^ a b c d e f Oliver Büchner; Mathias S. Wickleder (2004). "Tetranitratogoldsäure, (H5O2)[Au(NO3)4]·H2O: Synthese, Kristallstruktur und thermisches Verhalten des ersten sauren Nitrates des Goldes". Zeitschrift für anorganische und allgemeine Chemie (in German). 630 (7): 1079–1083. doi:10.1002/zaac.200400092.
- ^ A. Jamieson Walker (1924). The Alkali-metals and Their Congeners. the University of California: C. Griffin. p. 349.
- ^ D. P. Graddon; H. Taube; A. G. Maddock (2017). An Introduction to Co-Ordination Chemistry (Ebook) (2nd ed.). Elsevier Science. p. 148. ISBN 9781483184111.
- ^ a b Harry Mann Gordin (1913). Elementary Chemistry (1 ed.). the University of Wisconsin - Madison: Medico-dental Publishing Company. p. 437.
- ^ Ripan R., Chetyanu I. (1972). Inorganic chemistry. Chemistry of metals. Vol. 2. Moscow: World.
- ^ B. O. Field; C. J. Hardy (1964). "Volatile and anhydrous nitrato-complexes of metals: preparation by the use of dinitrogen pentoxide, and measurement of infrared spectra". Journal of the Chemical Society: 4428–4434. doi:10.1039/JR9640004428.
- ^ Mathias S. Wickleder; Oliver Büchner; Frauke Gerlach; Mandus Necke; Katharina Al-Shamery; Thomas Wich; Tim Luttermann (2008). "Synthesis, Characterization and Electron Beam Assisted Decomposition of (NO2)[Au(NO3)4]". Chemistry of Materials. 20 (16): 5181–5185. doi:10.1021/cm800066r.
- ^ Weishaupt, Martin; Strähle, Joachim (1976). "Kristallstruktur und Schwingungsspektrum des Tetrammingold(III) -nitrats" [Crystal Structure and Vibrational Spectrum of Tetraamminegold(III)-Nitrate]. Zeitschrift für Naturforschung B (in German). 31 (5): 554–557. doi:10.1515/znb-1976-0505.
- ^ Skibsted, L. H.; Bjerrum, Jannik (1974). "Studies on Gold Complexes. I. Robustness, Stability and Acid Dissociation of the Tetramminegold(III) Ion". Acta Chemica Scandinavica. 28: 740–746. doi:10.3891/acta.chem.scand.28a-0740.
- ^ Michel Manfait; Alain J.P. Alix; Charles Kappenstein (1981). "Raman and infrared studies of the square planar tetraammine gold(III) nitrate and its deuterate". Inorganica Chimica Acta. 50: 147–152. doi:10.1016/S0020-1693(00)83735-4.