CN102976360B - Thiocyanate-containing gold complex as well as preparation method and application thereof - Google Patents

Abstract

The present invention relates to a gold complex containing thiocyanate and its preparation method and application. The general formula of the compound is M _r [AuL _m ] _q xH ₂ O, L represents the thiocyanate acting as a gold ligand, m represents its coordination number, [AuL _m ] is the core component of the complex, q represents the number of [AuL _m ], M represents the cation in balance with [AuL _m ], r represents the number of M, and x represents the gold The amount of crystal water contained in the complex molecule; the valence of Au is positive 1 valence; [AuL _m ] the overall valence is zero valence or negative 1 valence; where, m and q are both positive integers, and r and x are both is zero or a positive integer. This type of complex can be applied to the fields of electroplating gold, chemical immersion gold, medicine, ceramics, catalyst and gold nanomaterials manufacturing; the gold complex containing thiocyanate can also be used as an intermediate and further used in the production of other gold compounds. synthesis.

Description

A kind of gold complex containing thiocyanate and its preparation method and application

technical field

The present invention relates to a preparation method and application of a kind of gold complex compound (also called coordination compound) without nitrile and cyanide {CN ^— }.

Background technique

In industries such as printed circuit board (referred to as PCB) production, metal plating, metal powder, medicine (such as treatment of rheumatism), catalyst manufacturing and wet gold extraction, etc. Gold complexes, this type of compound is characterized by the formation of a coordination bond between the central metal gold and the ligand. Gold complexes containing cyanide or nitrile are the main gold salts currently used in gold plating, such as gold cyanide M ⁺ [Au(CN) ₂ ] ^— (M=Na ⁺ ,K ⁺ ,NH ₄ ⁺ ), citrate gold salt containing malononitrile [CN200710193015.4; CN200710193014.X], etc., as well as cyanide and organic nitrile compounds used in gold extraction. There are great potential safety hazards and environmental hazards in both the process and the wastewater treatment after use. Gold complexes and their solutions using sulfite and thiosulfate as ligands have low stability and thus limit their use; gold complexes and solutions using halogen anions as ligands are corrosive, stable Problems such as safety, cost and specific application performance also limit its application in fields such as surface treatment. Thiocyanate can be used as a gold ligand to form gold complexes related to gold, in which the logarithmic value of the stability constant of the "aureous-thiocyanate" complex anion at room temperature is as high as 23 or more [①Li Dingxin, Extraction and Refining of Precious Metals, Central South University of Technology Press (1991), PP: 64], is a gold complex with low toxicity, environmental friendliness and worth exploring; however, there is still no related complex product on the global market [② Yu Jianmin, Handbook of Noble Metal Compounds and Complex Synthesis, Chemical Industry Press (2009), PP: 65; ③http://www.jandjmaterials.com; ④http://www.surepure.com; ⑤http://en.wikipedia.org] , and there is no report on the synthesis, performance and use of pure gold metal complexes of this class. It is the purpose of the present invention to develop related synthesis techniques and preparation methods to prepare gold complexes containing aurous and thiocyanate groups, and to apply them in the fields of surface treatment and the like.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention aims to provide a gold complex containing thiocyanate and its preparation method and application. The gold complex does not contain toxic nitrile, cyanide {CN ^— }, and can be used in the fields of electroplating gold, chemical immersion gold, medicine, ceramics, catalyst and gold nanomaterials; it can also be used as an intermediate for other Synthesis of gold compounds.

For realizing the above object, technical scheme of the present invention is:

One of the technical solutions:

A gold complex containing thiocyanate, the general formula of the compound is M _r [AuL _m ] _q xH ₂ O, L represents the thiocyanate acting as a gold ligand, m represents its coordination number, [AuL _m ] is the core component of the complex, q represents the number of [AuL _m ], M represents the cation that is in balance with [AuL _m ] and enables the gold complex to dissolve in water or other solvents, r Represents the number of M, and x represents the quantity of crystal water contained in the gold complex molecule; the valence of Au is positive 1; wherein, m and q are both positive integers, and r and x are both zero or positive integers.

Said M is preferably potassium ion, ammonium ion, sodium ion or magnesium ion.

The overall valence state of [AuL _m ] is preferably zero valence or minus 1 valence.

The gold complex is more preferably AuSCN·H ₂ O, NH ₄ [Au(SCN) ₂ ]·2H ₂ O or AuSCN.

The second technical solution:

The method for preparing the gold complex containing thiocyanate: select a material that does not have a side reaction with the gold compound raw material and thiocyanate as a dispersion medium, and mix the material containing the gold compound and the material containing thiocyanate according to the gold Mix and react with the molar ratio of 1 to 5 containing thiocyanate to generate a substance containing the core component [AuL _m ], then concentrate, crystallize, separate solid-liquid, wash and purify, and dry to obtain the substance containing Gold complex of thiocyanate.

The gold-containing compound is preferably selected from aurous chloride, aurous thiourea, chloroauric acid or gold trichloride; the material containing thiocyanate is preferably ammonium thiocyanate, sodium thiocyanate or thiocyanate Potassium; the dispersion medium is preferably an inert substance that does not chemically react with the gold compound raw material and the thiocyanate-containing raw material; more preferably, the dispersion medium is preferably an organic solvent such as acetone, ethylene glycol butyl ether, or the like.

The third technical solution:

The invention provides the application of the thiocyanate-containing gold complex in the preparation of mixed gold complexes. The mixed gold complex uses thiocyanate as an external ligand, and neutral Ligand as a mixed-type gold complex formed by an internal ligand, its chemical formula is [Au(L ^* _n )L _m ] _q xH ₂ O, where L ^* represents a neutral ligand, and L ^* is selected from sulfur Urea compounds, dimethylhydantoin (Hydantoin) or imidazoles, n represents the number of L ^* , n is a positive integer; L represents the thiocyanate as a gold ligand, m represents its coordination number, q represents [ Au(L ^* _n )L _m ], x represents the quantity of crystal water contained in the gold complex molecule; where m and s are both positive integers not equal to zero.

The chemical formula of the miscible gold complex is preferably [Au(ATU)SCN]·H ₂ O, wherein ATU is allylthiourea.

The application of the gold complex containing thiocyanate in electroplating gold, chemical immersion gold, and preparation of ceramic gold water. The present invention also provides the application of the thiocyanate-containing gold complex in the preparation of medicines, catalysts or gold nanomaterials.

The fourth technical solution:

A mixed gold complex, with thiocyanate as the external ligand and a neutral ligand as the internal ligand, its chemical formula is [Au(L ^* _n ) L _m ] _s ·xH ₂ O, wherein L ^* represents a neutral ligand, L ^* is selected from thiourea compounds, dimethylhydantoin or imidazoles, n represents the number of L ^* , n is a positive integer, L represents Thiocyanate acting as a gold ligand, m represents its coordination number, s represents the number of [Au(L ^* _n )L _m ], x represents the number of crystallization water contained in the gold complex molecule; where, m , s are both positive integers not equal to zero.

The chemical formula of the miscible gold complex is preferably [Au(ATU)SCN]·H ₂ O, wherein ATU is allylthiourea.

The present invention is further explained and illustrated below:

The chemical formula of this type of complex is M _r [AuL _m ] _q ^. xH ₂ O, wherein: [AuL _m ] is the core component of the complex, and q represents the value of the core component in the gold complex. Quantity, its value can be an integer such as 1, 2, 3; m represents the coordination number in this type of complex, and its value is a positive integer not equal to zero, such as 1, 2, 3, etc. M represents cations balanced with [AuL _m ], such as potassium ions, ammonium ions, sodium ions, magnesium ions, etc.; and cations formed by organic compounds, such as cations cationized by organic amine compounds containing amino NH ₂ , such as positive monovalent cations (ionic formula C ₂ H ₉ N ₂ ⁺ ) formed after cationization of ethylenediamine (molecular formula C ₂ H ₈ N ₂ ), and so on. r represents the number of such cations, and its value can be an integer such as 0 or 1, 2, 3; x represents the amount of crystal water that may be contained in the gold complex molecule, and its value is 0 or 1, 2 , 3 and other integers. When r is zero, the general formula of this kind of complex is simplified to [AuL _m ] _q ^. xH ₂ O.

Compared with the prior art, the present invention has the advantages of:

The invention provides a gold complex compound containing thiocyanate, its preparation method and application. The gold complex does not contain toxic nitrile, cyanide {CN ^— }, and can be used in the fields of electroplating gold, chemical immersion gold, medicine, ceramics, catalyst and gold nanomaterials; it can also be used as an intermediate for other Synthesis of gold compounds.

Detailed ways

Below in conjunction with embodiment the present invention will be further described.

Example 1:

Get the aurous chloride that gold content is 1 gram, it is dissolved in 1 liter of the mixed solution that contains hydrochloric acid and ammonium chloride, in this mixed solution, drip the ammonium thiocyanate solution that mass concentration is 5% under room temperature, make The molar ratio of thiocyanate to gold is 1, a coordination precipitation reaction occurs, until no more precipitates are produced, the solid and liquid are separated, the resulting precipitates are washed with water or other hydrophilic solvents, and dried at low temperature (≤80°C) A solid product was obtained, weighing 1.2 g. The analysis results of the elements C, H, O, N, and S of the product show that it is gold thiocyanate AuSCN.H ₂ O containing a crystal water, and the results of the gold assay show that its purity is 98%. Infrared spectrum The results show that it is coordinated with aurite by sulfur as a coordinating element; it shows that the corresponding aurite complex product can be prepared according to this method.

Application: Dissolve the above AuSCN.H ₂ O product in ammonium thiocyanate solution, adjust its gold concentration to 1~2g/L, pH to 2~5, at a temperature of 40~60°C, and a plating time of 9~ The electroless gold plating test was carried out on the nickel-plated PCB (printed circuit board) under the condition of 12 minutes (min), and it was found that the thickness of the immersion gold obtained was more than 0.11 μm, and the quality indicators such as bonding force and color could meet the requirements of the PCB industry.

Example 2:

Take gold trichloride with a gold content of 2 grams, dissolve it in 1 liter of a solution containing 10% hydrochloric acid (V/V), add 5% methionine solution dropwise to the solution at 20-45°C to Until no new turbidity is produced, the supernatant is separated by decantation, and the resulting turbidity is washed with water or other hydrophilic solvents if necessary. For the obtained turbidity, the molar ratio of 1:1.2 Mixed with ammonium thiocyanate solution with a mass concentration of 5%, it was found that obvious precipitates were produced until no more precipitates were produced; the resulting precipitate was subjected to solid-liquid separation, and thiocyanic acid with a mass concentration of 5% was added thereto Potassium solution until the precipitate is completely dissolved, and the resulting mother liquor is dried at low temperature (≤80°C) to obtain a solid product weighing 2.7 grams. The analysis results of the elements C, H, O, N, and S of the product show that it is potassium aurous thiocyanate K[Au(SCN) ₂ ].2H ₂ O containing two crystal waters. Its purity is 96%, and the results of infrared spectroscopy show that it is coordinated with aurous metal by sulfur as a coordinating element; it shows that an aurous complex product with thiocyanate as a ligand can be prepared according to this method.

Application: Dissolve the above K[Au(SCN) ₂ ].2H ₂ O product in water, adjust its gold concentration to 2~4g/L, pH to 1~4, at a temperature of 35~50°C and a current density of 150 Under the conditions of ~250 amps/square meter and a plating time of 5 to 15 minutes (min), the electroplating test was carried out with brass as the substrate plate. It was found that the gold particles of the obtained gold plating layer were fine, the bonding force was good, and the color was bright. Quality indicators can meet the requirements of metal plating.

Example 3:

Take chloroauric acid with a gold content of 1.5 grams, dissolve it in 1 liter of acetone, and add dropwise a solution of ammonium thiocyanate in acetone with a mass concentration of 2% in the mixed solution within the range of 10 to 40 ° C, so that the sulfur The molar ratio of cyanate to gold is 2.3 to 3.1. After 3 to 6 hours, the precipitate at the bottom of the reactor is collected, separated from solid and liquid, washed with acetone or other hydrophilic solvents, and dried in vacuum to obtain a The intermediate solid product, whose elemental analysis and assay measurement all show that its main component is AuSCN, weighing 0.85 grams;

Application 1: Add 2% allylthiourea (abbreviated as ATU, the same below) solution to the above-mentioned AuSCN solid product until the above-mentioned precipitate is just dissolved, and the obtained mother liquor is concentrated at low temperature (≤25°C) and dried at low temperature Obtain a kind of colorless solid afterward, weigh 1.6 gram; The element C of this product, H, O, N, the result of S analysis show that it is the mixed type gold metal complex [Au(ATU) containing 1 water of crystallization. SCN].H ₂ O. Assay results show that its purity is 97.5%. Infrared spectrum results show that the element sulfur closest to sub-golden coordination comes from ATU. It shows that this method can be used to prepare mixed aurite complexes with thiocyanate as the external coordination group and thiourea neutral ligands as the internal coordination group.

Application 2: Use the above [Au(ATU)SCN].H ₂ O as the gold source, and use titanium compounds (titanium dioxide), bismuth compounds (bismuth oxide), chromium compounds (chromium oxide), and rhodium compounds that are commonly used in the ceramic industry (rhodium sulfate) as ingredients, industrial alcohol, cyclohexanone, tetrahydrofuran, and turpentine as solvents, prepared ceramic gold water with contents of Au10%, Bi0.3%, Cr0.5%, Rh0.06%, and found that it was stable Good wear resistance, no precipitation; according to the ZBY 24004-89 standard, the relevant ceramic gold decoration performance test was carried out in the range of 750-850 °C, and the results showed that the obtained gold layer had good wear resistance (up to 1200 times), bright color, no Variegated, no white spots, no red gold.

Claims (3)

1. mixed matching gold complex, is characterized in that, described mixed matching gold complex is using thiocyanate ion as outer part, and using neutral ligand as the mixed matching gold complex that interior part was formed, its chemical formula is [Au(L ^* _n) L _m] _sxH ₂o, wherein L ^*represent neutral ligand, L ^*be selected from thiourea, n represents L ^*quantity, n is positive integer, the thiocyanate ion of golden part is served as in L representative, m represents its ligancy, s represents [Au(L ^* _n) L _m] quantity, x represents the quantity of the crystal water containing in this gold complex molecule; Wherein, m, s are the positive integer that is not equal to zero.

2. mixed matching gold complex according to claim 1, is characterized in that, the chemical formula of described mixed matching gold complex is [Au (ATU) SCN] H ₂o, wherein ATU is thiosinamine.

The described mixed matching gold complex of one of claim 1-2 aspect electrogilding, chemical turmeric, prepare the application of aspect, ceramic Jinsui River.