Gold chloride, is the most commoninorganicGold compound, chemical formula is AuClthree。Roman numerals in the name indicate goldValenceIs+3, which is the most stable valence state among its many compounds.Gold will also form another kindchloride——Aurous chloride(AuCl), it does not have AuClthreestable.In addition, dissolve gold inAqua regiaWill produceChloroauric acid（H[AuClfour]), sometimes referred to as "gold trichloride" or "trihydrate gold chloride (III)".
Gold chloride (III) is highly hygroscopic and easily soluble inwaterandethanol。When the temperature is higher than 160 ℃ or under light, it will decompose and produce many kinds ofligandOfComplex。
character:Ruby crystal (obtained by sublimation) or reddish brown to dark red crystal block.[1]Extremely hygroscopic and deliquescent.Vulnerable to sunlight.Strong thermal decomposition into chlorineHydrogen chlorideHejin.Irritating.
Solubility: easily soluble in water and ethanol, soluble in ether, slightly soluble inchloroform。Dissolve in water to generate HtwoAuClthreeO，It is slightly stable in acid liquid.[2]Insolublecarbon disulfide。
Density: 3.9g/cmthree
Gold chloride
Melting point: 254 ℃
Storage: ampoule sealed, cool and dry.
Purpose: mainly used forgold-plated、Special ink, medicine, porcelain gold, red glass, etc., and variousGold compoundRaw materials for production, photography andChemical Reagents。In addition, the micro determination of rubidium and cesium was carried out.Determination of alkaloids, etc.Dissolved in hydrochloric acid, it becomes chloroauric acid, and can also be used foremulsionGolden sensitization.
Control information: This product is not controlled.
Quality Inspection Information Quality Inspection Item Indicator Value:
Content (calculated by Au),% ≥ 47.8
Alkali metals and other metals,% ≤ 0.15
Alcohol ether mixture solution test qualified
Total nitrogen (N),% ≤ 0.01
structure
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Both solid and gaseous gold trichloride are dimers;Bromide III of goldGold bromideAuBrthreeSo it is.The two Aus are located at the center of the two square planes.This structure is called planar structure, AlClthreeAnd FeClthreeIt also belongs to this structure.AuClthreeThe chemical bonds inCovalent, reflecting its high valence and relatively highElectronegativity。
The most commonly used method for preparing gold chloride (III) is directly under high temperaturechlorinationThis metal:
2Au + 3Cltwo==High temperature==2AuClthree
Specific method: to Na [AuClfour]Add inSulfiteAnd precipitategoldAfter full washing, dry at 180 ℃.The obtained powdered gold is placed in a porcelain boat in a glass tube, and chlorine gas with a pressure of 900 ～ 950mmHg (1mmHg=133322Pa) is introduced, and the reaction temperature is controlled at 225 ～ 250 ℃ to prepare gold chloride.[2]
The chemical property is extremely unstable, and it is easy to decompose when heated.normal atmospheric temperatureThe aqueous solution is colorless.Energy and solubilityalkaliReaction:
AuClthree+ 3NaOH ==== Au(OH)three
+ 3NaCl
AuClthree+ 3KOH ==== Au(OH)three
+ 3KCl
Generally, it cannot react with acid.
application area
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Gold (III) salts, especially Na [AuClfour](by AuClthreeAnd NaCl), which can replace the more toxic mercury (II) salt asAlkyneCatalyst for the reaction.For example, it is prepared through the water cooperation of terminal alkynesMethyl ketone。
Under these conditions, the yield of ketone can reach 90%.Another use is as a catalyst in the amination reaction of alkynes.In recent years, AuClthreeIt has begun to attract the attention of organic chemists because it can be used as a weak acid catalyst for other chemical reactions, such as:Aromatic hydrocarbonOfAlkylationReaction and conversion of furan to phenol (see below).This chemical reaction is also used in the synthesis of organic compounds and in the pharmaceutical industry.For example, 2-methylfuran (sterane) can be compared withMethyl vinyl ketoneHappened smoothlyAlkylation reaction。
At room temperature, use 1mole% AuCl in methylnitrilethreeOnly 40 minutes of reaction was needed to produce 91% of the product.This amount should be noted, because furan and ketone are very easy to occur in acidic environmentpolymerizationAnd other side effects.Sometimes, when alkynes existphenol。
In this reaction, the carbon atoms undergo a series of complex rearrangements to produce new aromatic rings.
Calculate chemical data
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data[1]：
1. Reference value for drainage parameter calculation (XlogP): None
2. Number of hydrogen bond donors: 0
3. Number of hydrogen bond receptors: 0
4. Number of rotatable chemical bonds: 0
5. Number of tautomers: none
6. Topological molecular polar surface area 0
7. Number of heavy atoms: 4
8. Surface charge: 0
9. Complexity: 8
10. Number of isotope atoms: 0
11. Determine the number of atomic structure centers: 0
12. Number of uncertain atomic structure centers: 0
13. Determine the number of chemical bond structural centers: 0
14. Number of indeterminate chemical bond structure centers: 0
15. Number of covalent bond units: 1
Molecular structure data
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data[1]：
1. Molar refractive index: None available
2. Molar volume (cmthree/Mol): None available
3. Isotonic specific volume (90.2K): none available
4. Surface tension (dyne/cm): none available
5. Dielectric constant: None available
6. Polarization (10-24cmthree）: No available
7. Single isotope mass: 301.873058 Da
8. Nominal mass: 302 Da
9. Average mass: 303.3256 Da
Misconception
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Viewpoint: It is believed that chloroauric acid and gold chloride are the same substance.
Analysis: chloroauric acid is obtained by dissolving gold trichloride in concentrated hydrochloric acid, and gold chloride is a salt.
Chloroauric acidFormula H [AuClfour]·4HtwoO。The molecular weight is 411.85.Yellow needle shaped crystals.Toxic!Corrosive.Easily soluble in water, soluble in ethanol, ether, slightly soluble inTrichloromethane。Thermal decomposition.Exposed to generate black spots, which are decomposed intoGold trichloride。Brown gold can be precipitated by reacting with KI in alkaline solution.When meeting tin dichloride in acid solution, it will produce "cinnamon purple".Use methyl orange to make its aqueous solution purple, drop 1~3 drops of hydrochloric acid to make it green, and then encounter the gold salt solution, it will become lavender;Add cold potassium hydroxide solution to generate gold hydroxide precipitation, and passsulfur dioxideIs reduced to gold powder.Preparation method: dissolve pure gold in aqua regia (or chlorine saturated hydrochloric acid), distill and crystallize it.Use: It is used for electrogilding and photography, gold powder, red glass, drugs for treating tuberculosis, and microanalysis of Rb and Cs.
Hazard level
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Hazard level: 8
Hazard level: 34
Security level: 20-26-36/37/39-45
UN No.: UN3260
Unless otherwise specified, all data shall comply with the International System of Units and conditions from standard conditions (0 ℃, 100 kPa).
matters needing attention
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Gold trichloride is very irritating. When handling gold trichloride, you should wear gloves and goggles to avoid direct contact with materials. If you accidentally touch gold trichloride, you should immediately seek medical advice.
