The method of obtaining tris-beta-diketonates rare platinum metals

 

(57) Abstract:

Use: inorganic chemistry, synthesis of volatile complexes of Tris-beta-diketonates rare platinum metals. The essence of the method: exavermerct platinum metal in the higher oxidation state is in contact with an excess of beta-diketone or its salt when heated. The reaction is carried out in the presence of a reducing agent in the medium of 0.1 N perchloric or 0.2 N hydrofluoric acid. Then the reaction mixture is alkalinized to pH 1 to 7 depending on the metal. As a reducing agent using water or 0.1 N solution of HClO4or 0.2 N solution of HF, or aliphatic alcohols with the number of carbon atoms of the C1- C5or hydrazine hydrate. The technical result of the invention is the creation of a unified method of synthesis allowing to extend the range of the used ligands and increase yields salts, 1 AD. and 2 C.p. f-crystals, 8 etc.

The invention relates to methods of obtaining Tris-beta-diketonates rare platinum metals General formula (R'-CO-CH-CO-R)3M, where M Rh(III), Ir(III), Ru(III), Os(III); R', R" -CH3, -CF3, -CF3, -C6H5, -C(CH3)3, -C3F7in various combinations, relates to the field of inorganic chemistry synthesis of volatile kislorodnykh the first transport of metals through a volatile metal-containing compounds, gas and gas-liquid chromatography, methods zone sublimation, extraction, etc. Practically useful for condemnation of highly pure metals and their films the gas-phase thermolysis of these compounds in obtaining protective, corrosion-resistant, reflective coatings and other Application of the invention it is possible to Express the preparation of standard samples and solutions of platinum metals used in the calibration of analytical equipment (spectroscopy, atomic absorption and electronic spectrophotometry, volumetric, gravimetric analysis, and so on)

Known methods for producing Tris-beta-diketonates of platinum group metals, based on a reaction between beta-diketones with svezheosazhdennoi the corresponding hydroxides of metals by heating the reactants in the range of pH 5 to 6 with subsequent recrystallization of target products from solutions in chloroform, benzene, or by chromatographic purification on alumina [1]

Presents methods of synthesis, where as starting compounds in the reaction with beta-diketones are used equatoriana chlorides of these metals. These reactions are carried out on prolonged heating (about 40 hours) in an inert atmosphere of nitrogen at constant what Cetona is a large excess of ligand and buffer solutions with a high capacity.

The main disadvantages of these methods are: the necessity of first obtaining purified reagents (hydroxide, aquatronic forms in solutions etc), the impossibility of achieving a high yield of the target products, which in the case of beta-diketonates of rhodium (III) is 50-70% and for complexes of iridium (III), ruthenium (III) and osmium (III) does not exceed 5-20% of the length of the process, the need to maintain an inert atmosphere, a constant pH environment, introduction to the synthesis of a significant excess of ligand. Chemical explanation of the small yield of products is weak coordinating ability of the oxygen atoms of acetylacetone in comparison with the chloride ligands or highly polymerized by hydroxides of noble metals. In [3] considers the many factors that affect the reaction of interaction of rhodium chloride (III) with acetylacetone. The main conclusion of the authors is the conclusion about the necessity of increasing the number of acetylacetone dozens of times from stoichiometric to suppress the competing influence of chlorine-ion, which is highly undesirable when the use of expensive and scarce its fluorinated derivatives. There are also flow side R acid, so with gidrolizuyutza (pH-9) rhodium chloride.

Thus, for the reaction of complex formation with acetylacetone and its derivatives essential reference chemical form, which is a noble metal. From this perspective, the most preferred are the coordination and"loosely coupled" type ligands nitrate, phosphate, sulfate, acetate ions. However, the low availability of these compounds, which are obtained with low output and by multi-step reactions, makes the search for other methods of synthesis.

The technical essence is the closest method [2] based on a long (about 2 days) hydrolytic decomposition hexachloride acid or hydrated trichloride iridium. Into force of kinetic inertia and low depths of flow of hydrolysis of chlorocomplexes iridium appear the main disadvantages of this method: small output kislorodozavisimogo beta-diketone (18%), the formation of complexes of iridium with uglerodsesola acetylacetonato group, dimeric compounds of unknown composition, etc. This requires extra carrying dividing extraction procedures dichloromethane. High dlitelnosti complexity of its execution.

However, in the literature [4] presents experimental results that allow us to estimate thermodynamic and kinetic parameters of reactions going with the participation of the fluoride complexes of the platinum metals. It follows that herocomplex in aqueous solution has less stability compared with other halogenosilanes, and coordinated the fluoride ion is a weak TRANS effect. These assumptions suggest that herocomplex respective platinum group metals can be a promising source connections for a given goal-directed synthesis.

The present invention is the creation of a unified method for the synthesis of Tris-beta-diketonates rare platinum metals, allowing you to extend the range of the used ligands and to increase the chemical yield of these salts.

The problem is solved in that the reagent is used as hexatonics platinum metal in the higher oxidation and reaction with beta-diketone or its salt is carried out in a medium of 0.1 N perchloric or 0.2 N hydrofluoric acid in the presence of a reducing agent, followed by alkalization of the solution. Depending on the type of metals Voss is="ptx2">

Distinctive features of the invention are used as a source of herocomplex of these metals in the desired oxidation States, their hydrolytic recovery, pre-equately. Another difference is in the choice of acid HClO4or HF acid residues which are not coordinating ligands. In addition, as a reducing agent is water or solutions of alcohols and hydrate of hydrazine.

In connection with the foregoing, there is a need to get herocomplex iridium, rhodium, osmium and ruthenium in the oxidation state 3+ for the subsequent synthesis of Tris-beta-diketonates metal. Due to the high oxidation potential of fluoride and other fluorinating reagents obtained forecastles implement high (IV, V) oxidation state of the Central atom. Therefore, in the future, the required reactions restoring the last to obtain the oxidation state 3+. For some complex fluorides as a reducing agent can be water molecules, which allows the reaction of reductive hydrolysis without the use of polluting the system of reducing agents. If necessary use more active reducing agents, celesia and water.

So, for rhodium this transition is completed by the formation of execuation species Rh(H2O)36+for iridium recovery of K2IrF6ends on the phase formation of K3IrF6which is a structural analogue of K3RhF6. The hydrolytic products of the interaction of herocomplex Ru(IV) and Os(IV) will be oxohydroxide polymer structure.

The most important consequence in determining the substance of the proposed method is the fact destabilization of the internal sphere of the original ftorokompleksov and significant ligand labilization of fluorine with lowering the oxidation state of the Central atom. Purposefully, it can be used to replace these mobilisierung of fluorine ions with water molecules or other kislorodolechenie ligands (in this case beta-diketones).

The main precondition for use as initial reagents it is the highest herocomplex is the possibility of obtaining them in one-step procedure of the most accessible raw materials mobiles or powders of ruthenium, rhodium, osmium or iridium reaction:

< / BR>
Herocomplex of these metals in higher oxidation States (Ir(V), Ru(V), Rh(IV), Os(V)) is restored when Nisim recovery alcohols or hydrazine hydrate to metals (III) and the interaction of the products reductive hydrolysis to the corresponding beta-diketones or their salts. Another difference is that the ligand is administered in an acidic solution and then in the presence of a beta-diketone spend changing pH by adding alkali solution. Carrying out the reaction of beta-diketones with products of a reductive hydrolysis of the highest hexafluorocomplexes allows the entire synthesis process be reduced to two stages:

1. Obtaining hexafluorocomplexes metals in higher oxidation States using commercially available powdered metals or their chlorides.

2. The synthesis of Tris-beta-diketonates of the corresponding metal.

The inventive method is General, applicable to obtain Tris-beta-diketonates of all the platinum metals with different types of beta-diketonate ligands, allows to increase the output of Tris-acetylacetonates of Ru, Rh, Ir, Os up to 90-95% and to expand the range of the resulting high yield of target products.

Used the interval of pH values of solutions (1-7) in the present method of synthesis of beta-diketonates of platinum group metals is determined by the nature of the metal and ligand. More acidic solutions (pH 1-2) used in the synthesis of compounds of iridium with acetylacetone and fluorinated beta-diketones. For large values of the ABC and the partial formation of compounds of iridium polymeric nature, that reduces the output of the Tris-beta-diketonates. In the case of ruthenium, rhodium, osmium need for gradual changes in pH from 1 to 6-7 explains, on the one hand, the deeper the substitution of fluorine ions to water molecules, but not ions hydroxide (pH-1) in restored form herocomplex metals, and on the other greater degree of binding of beta-diketones with metal ions at a pH of 6-7, given the acidic properties of the enol form.

Example 1. Getting acetylacetonate Rh(III).

A portion of K2RhF6mass 30,26 g (0,101 mol) was placed in a Teflon beaker with a volume of 1 l, add 500 ml of hydrofluoric acid (1:10 dilution). The reaction mixture is heated to boiling with stirring and full transition of rhodium in the solution color change from purple to yellow-orange. Then the solution is cooled and neutralize excess acid 1 N KOH solution until the pH is 2 to 3. The resulting precipitate is filtered on a Teflon funnel through a paper filter. Thereafter, under stirring in parts injected a mixture of 25 ml of acetylacetone in 40 ml of 96% ethyl alcohol. This immediately formed a loose yellow precipitate, which increases its volume when the progressive alkalinization of KOH solution to pH 6-7. About the s acetylacetonate Rh(III) are combined with the previous one. The remaining portion of the product is extracted with benzene, which, after separation of aqueous-organic layer evaporated. Obtained in this way acetylacetonate Rh(III) sublimate in a vacuum (P-510-2Torr, T - 220oC). The yield of purified target product is 94-96%

Example 2. Getting triftoratsetilatsetonom Rh(III).

A portion of K2RhF6weight of 10.5 g (being 0.036 mol) was placed in a quartz glass 0.5 l, add 200 ml of HCLO4(dilution 1:1). The reaction mixture is heated to boiling with stirring and full transition of rhodium in the solution color change from purple to yellow-orange. Then under stirring in parts injected a mixture of 33 g (0,214 mol) of triflluoroacetylacetone in 40 ml of methyl alcohol. This forms a yellow precipitate, which increases with the gradual alkalinization of KOH solution to pH 5-6. The formed precipitate is filtered off and the mother liquor is extracted with benzene, which, after separation of aqueous-organic layer evaporated. Thus obtained cryptorchidectomy Rh(III) combine with the previous, sublimate in a vacuum (P-510-2Torr, T - 150oC). The yield of purified target product is 80-85%

Example 3. Getting sexafter the UB>Ir6the hydrazine hydrate, dissolve by heating (90oC) in 50 ml of 40% hydrofluoric acid, evaporated to moist salts, diluted with water (50 ml, pH 1) and add 3-fold excess salt hexafluoroacetylacetonate potassium (44,3 g; 0,180 mol) dissolved in water (30 ml). The reaction is carried out at heating (90oC) and stirring for 5 hours Received orange complex is extracted with benzene, evaporated and purified by vacuum sublimation at P-510-2Topp and T 50oC. the Yield of purified hexafluoroacetylacetonate Ir(III) is 70-75%

Example 4. Getting dipivaloylmethanate Ir(III).

A portion of K3IrF6(15 g; 0.035 mol) obtained in the recovery of K2IrF6the hydrazine hydrate, dissolve by heating (90oC) in 40 ml of 40% hydrofluoric acid and add an equivalent amount of (19.6 g; 0,107 mol) of dipivaloylmethanate dissolved in 40 ml of ethanol. The reaction is performed by heating (90oC) and stirring for 7 hours Received a yellow-orange complex is extracted with chloroform, evaporated and sublimate in a vacuum at P-510-2Topp and T 180oC. Yield purified of dipivaloylmethanate Ir(III) is 50-55%

Example 5. Getting benzoylacetonate Ru(III).

The portion K is Stanovlenie then add another 30 ml of isopropyl alcohol, then, while heating and stirring 7.6 g (0,047 mole) of benzoylacetone dissolved in 20 ml of ethanol. The reaction is carried out for 2 hours and Then adding concentrated aqueous KOH solution was adjusted pH to 6-7. Received a bright red crystals of the complex is extracted with benzene. Clean the connections are realized by means of recrystallization from the system chloroform hexane. The output of the purified compound is 70%

Example 6. Getting resolicitation Ru(III).

A portion KRuF6(15 g; 0,059 mol) is dissolved by heating (90oC) in 50 ml of 40% hydrofluoric acid for further recovery then add another 30 ml of ethanol, followed by heating and stirring 12.7 g (0,059 mol) of benzoyltrifluoroacetone dissolved in 25 ml of ethanol. The reaction is carried out for 3 hours by the Addition of concentrated aqueous KOH solution was adjusted pH to 6-7. The obtained red crystals of the complex is extracted with benzene. Clean the connections are realized by means of recrystallization from the system chloroform hexane. The output of the purified compound is 70%

Example 7. Getting acetylacetonate Os(III).

A portion KOsF6(8 g; is 0.023 mol) is dissolved by heating (90oC) 4 is in while heating and stirring of 11.5 g (0,115 mole) of a solution of acetylacetone in 20 ml of ethanol. The reaction is carried out for 30 min, then adding countryowned aqueous KOH solution was adjusted pH to 6-7. The obtained yellow crystals of the complex is extracted with benzene. Cleaning compounds carried out by the method of zone sublimation at P-510-2Topp and T 180oC. the Yield of purified compounds is 90%

Example 8. Getting pivaloyltrifluoracetonate Os(III).

A portion KOsF6(5 g; 0,025 mol) is dissolved by heating (90oC) in 25 ml of 40% hydrofluoric acid for further recovery then add another 25 ml of ethanol, 15 min while heating and stirring 2.9 g (0.015 mol) of a solution of pivaloyltrifluoroacetone in 15 ml of ethanol. The reaction is carried out for 1 h then adding concentrated aqueous solution of KOH bring the pH of the medium 6-7. The obtained yellow crystals of the complex is extracted with benzene. Cleaning compounds carried out by the method of zone sublimation at P-510-2Topp and T 15oC. the Yield of purified compound is 60%

Literature.

1. Dwjer F. P. A. M. Sargeson The preparation of Tris-acetylacetone-rhodium(III) and iridium (III). J. Am.Chem.Soc. 1953, v.75, No. 4, p. 984-985.

Benett M. A. Carbon-Bonded 2,4-Pentanedionato Complexes of Trivalent iridium. Inorg.Chem. 1976. v. 15, N 11, p.2930.

3. Belyaev A. C. Anchor: A. B. Fedotov , the return to index. 6. 1985.

Shipachev Century A. S. Zemskov Century Viola L. J. Study of redox processes involving hexafluoroplatinate and hexabromopalladate-ions in aqueous solutions. Coordination chemistry. so 6, vol. 6. 1980.

1. The method of obtaining Tris-beta-diketonates rare platinum metals (ruthenium, rhodium, osmium and iridium) interaction of the initial compounds of the platinum metal with an excess of beta-diketone under heating, followed by separation of the target product, characterized in that the reagent is used as exavermerct platinum metal in the higher oxidation and reaction with beta-diketone or its salt is carried out in a medium of 0.1 N perchloric or 0.2 N hydrofluoric acid in the presence of a reducing agent, followed by alkalization of the solution.

2. The method according to p. 1, characterized in that as the reductant use water or 0.1 N solution of HClO4or 0.2 NHF, aliphatic alcohols with the number of carbon atoms WITH1WITH5or hydrazine hydrate.

3. The method according to p. 1, characterized in that depending on the metal alkalization is carried out to a pH of 1 to 7.

 

Same patents:

The invention relates to a method for dialkyldithiophosphoric phthalo - and naphthalocyanines that can be used as oxidation catalysts, optical and electronic materials

-aminophenylacetate nickel, palladium and copper, and the method of production thereof" target="_blank">

The invention relates to organic chemistry, specifically to new chemical compounds - performancemanagement N,N'-ethylenebis-beta-aminophenylacetate Nickel, palladium and copper, which can be used as organic filters and photostabilization for organic liquids and polymers

< / BR>
and the way they are received, characterized in that the initial reaction of fluorinated diketones carried out in benzene in the presence of a catalyst - epirate boron TRIFLUORIDE with removal of water by azeotropic distillation

-aminophenylacetate nickel, palladium and copper, and the method of production thereof" target="_blank">

The invention relates to organic chemistry, specifically to new chemical compounds - performancemanagement N,N'-ethylenebis-beta-aminophenylacetate Nickel, palladium and copper, which can be used as organic filters and photostabilization for organic liquids and polymers

< / BR>
and the way they are received, characterized in that the initial reaction of fluorinated diketones carried out in benzene in the presence of a catalyst - epirate boron TRIFLUORIDE with removal of water by azeotropic distillation

The invention relates to methods for ORGANOMETALLIC compounds, in particular dilacerating complex iron lignosulfonate

The invention relates to the refining, and in particular to methods of allocation of residual oil fractions vanadyl-(EAP) and nigelbotterill (TM) products Parametrierung which have catalytic properties [1 and 2]

There is a method of allocation VP of oil or fractions by extraction with dimethylformamide [3]

The disadvantage of this method is the sharp decrease in the efficiency of extraction of the EAP in the transition from oil of low and medium density to high-viscosity heavy oil and residual fractions, which are more suitable raw material source for the selection of the EAP because of the much higher content compared with oils of low and medium density

The invention relates to new derivatives of (1-(-oxyethyl)-2-methyl-5-intorimidazole) has antibacterial, antitrichomonas, fungicidal and immunostimulatory activity

The invention relates to biologically active compounds of platinum (II)
The invention relates to a process for the production of copper phthalocyanine (PcCu), which can be used as Krasotel sensor, the component of the photosensitive layer

-aminophenylacetate nickel, palladium and copper, and the method of production thereof" target="_blank">

The invention relates to organic chemistry, specifically to new chemical compounds - performancemanagement N,N'-ethylenebis-beta-aminophenylacetate Nickel, palladium and copper, which can be used as organic filters and photostabilization for organic liquids and polymers

< / BR>
and the way they are received, characterized in that the initial reaction of fluorinated diketones carried out in benzene in the presence of a catalyst - epirate boron TRIFLUORIDE with removal of water by azeotropic distillation

3(methoxo)-(methoxo)- pentakis(acetylacetonato) copper (ii) ree (iii) barium" target="_blank">

The invention relates to a method for heterometallic acetylacetonates, containing atoms of copper, barium and one of rare earth elements (REE) in the ratio of SR:BA:RA 3:2:1

The invention relates to the field of chemistry of metal complexes with-diketones, particularly to a method of obtaining complexes of rare earth metals (REM) with a simple-diketone is acetylacetone, having the property of volatility
The invention relates to the field of recycling waste latinoreview catalysts on Al2O3basis

The invention relates to methods for extraction of platinum or platinum and rhenium from spent industrial catalysts used in the refining and petrochemical industries
The invention relates to methods for selection of palladium from industrial waste and can be used for selection of palladium electrolyte galvanic productions
Up!