SU883050A1 - Method of preparing dimeric clustered tetracarboxylate of molybdenum - Google Patents

Description

The invention relates to the field of chemistry and the fine chemical technology of rare elements, in particular to an improved method for producing a dimeric cluster molybdenum tetracarboxylate, which can be used ® to produce molybdenum catalysts, as well as the starting material in many organic and inorganic synthesis reactions.

A method of producing a dimeric cluster ¹⁰ tetracarboxylate molybdenum, in particular tetraformiata dimolibdena _{Μο Σ (O ^ CI-l} ) ^, .tetraatsetata dimolibdena by reaction with formic acid in an inert gas atmosphere at ⁹⁰ C for 1-1.5 h. the result is a yellow solution, which is filtered in an inert gas atmosphere and then cooled to 10 ° C for 12 hours, also in an inert atmosphere, taking care that the temperature does not drop by one or two degrees, since at'8 ° C freezing. the reaction mixture. A precipitate of the desired yellow product is isolated from the cooled solution with a yield of 72% [1]. The disadvantage of this method is the limited use of it only for those carboxylic acids that exist in the used temperature range (10-90 ° C) in the liquid state, and by their chemical properties are able to replace acetate groups in the original Mo _x (O ₂ CCHj. In addition , the method of producing tetraformate is multi-stage, all operations, including filtering and long-term purification of the product, should be carried out in an inert atmosphere. A special experimental complexity of this method is the long-term reaction of the solution at exactly 10 ° C and lowering it even by 2 ° C can lead to unsuccessful synthesis due to the freezing of the reaction mixture.

The closest in technical essence and the achieved result

883050 to the proposed is a method for producing a dimeric cluster molybdenum tetracarboxylate by reacting Mo (CO) g molybdenum carbonyl with carboxylic acid or its anhydride in diethylene glycol dimethyl ether (diglyme) by heating this mixture in a flask under reflux at 160 ° C in an inert atmosphere gas for 8 hours. The importance of a 30-fold excess of diglyme in relation to the amount of acetic acid, the use of carbon dioxide to create an inert atmosphere and the need for strict regulation are emphasized. the rate of temperature rise for 1.5 h with a total heating time of the reaction mixture of 8 h [2].

The disadvantages of this method are the need to maintain a high ₂ q temperature, as well as the use of significant quantities (thirty-fold excess) of an expensive diglyme solvent, duration (8 hours) and a multi-stage process, strict control of the temperature rise rate and unstable tetracarboxylate yield, which varies from 30 to 80% , depending on the amount of side molybdenum derivatives formed during the oxidation of Mo (C0) ₆ in the form of trinuclear complexes of molybdenum with acetate bridge groups.

The purpose of the invention is the simplification and intensification of the process, increasing the yield of the target product and expanding the range of target products.

This goal is achieved by the fact that according to the method for producing the dimer: cluster molybdenum tetracarboxylate, the dimeric molybdenum dimeric cluster chloride is used as the initial molybdenum compound, mainly KcMo ₂ Cl ₈ , (MncMo ₂ C 1 ₈ , (NH05 Mo ₂ SC-H _g 0 , and subjected to its interaction with a carboxylic acid or its salt, taken in a molar ratio of 1: (4-12), in a medium of water.

In this case, the interaction proceeds according to the following summary reaction scheme MozClj '+ 4RC00NHK ^ Mo _g (0 _g C8) _d . + 4ΝΗ ί ₍ 8θ 'and the reaction is carried out for 15-20 minutes

The initial chlorine-containing salt of dimolybdenum is dissolved with vigorous stirring in an aqueous solution of an acid or its salt, taken, as indicated, in excess. After 5 min, a precipitate of the dimeric cluster molybdenum tetracarboxylate is formed, characterized by very low solubility in water. To complete the precipitation, the reaction mixture can be cooled in ^a refrigerator at 5 C for 10-15 min.

The yield of the dimeric cluster molybdenum tetracarboxylate is quantitative (an attempt to determine molybdenum in the uterine solution did not lead to positive results). The purity of the obtained product is 99.97%.

The choice of reaction conditions, in particular the conduct of reactions in aqueous solutions, is due to the following reasons.

Derivatives MojClj '' and Mo ₂ C dissolve in water and can exist in aqueous solutions without breaking the metal-metal bond for 4 hours. At / This forms an intermediate aqua> complex that promotes further interaction with the carboxylic acid. If the reaction is carried out directly with a carboxylic acid in the absence of water, the molybdenum dimeric cluster tetracarboxylate does not form or is formed in low yield and does not precipitate into the solid phase. In addition, water, as a necessary component of the reaction, allows you to expand the number of carboxylic acids used due to interaction with their salts.

The selected ratio of the starting components 1: 4-12 are due to the following. When the ratio of the dimeric cluster molybdenum chloride: carboxylic acid or its salt is less than 1: 4, along with the main process, hydrolysis reactions take place, and the yield of the target product decreases. When the ratio of the components is greater than 1:12 in the reaction mixture, conditions are created for the coprecipitation of the carboxylic acid or its salt, and the purity of the desired product is impaired.

The process of obtaining a dimeric cluster molybdenum tetracarboxylate consists in the formation of an intermediate aquichlorocomplex of dimolybdenum, obtained by dissolving Mo ^ Clg ^ B in water, and in the subsequent interaction of this intermediate complex, in which the molybdenum-molybdenum bond is retained, with the prepared tat ligands, due to you or its salts.

Prim N _g 0.

A portion of the conic bridged acidic b 1 bimenical in water dissociation, Preparation of Mo ₂ (HCOO \

KuMoaClg (1 g) is placed in a flask containing 40 ml

0.5 N aqueous solution of HCBS; Kt | HojCl ₈ : HCOONHq - 1 ratio; 12. The mixture was stirred at room temperature for 5 minutes and the bright yellow product was separated by filtration, washed with two portions of distilled water, then with ethanol and dried under vacuum at room temperature. Purity according to chemical analysis and IR spectroscopy is 99.90%.

Found,%: But 48.5; C 11.7;

H 1.4.

Calculated,%: Mo 49.4; C 12.3;

H 1., 2

Example 2. Obtaining Mo ₂ (0 ₂ C-CH (OH) -C ₆ H ₅ ) _{| <} - derivative with mandelic acid (H mind).

A weighed portion (NHiJg-MojCC · H ^ O (0.2 g) is placed in a flask containing 20 ml of an aqueous solution containing 0.2452 g of mandelic acid, the ratio of the starting reagents is 1: 5. The mixture is vigorously stirred for 5 minutes. the complete precipitation of the dimeric cluster tetramindalate dimolybdenum solution with the precipitate is cooled to 5 ° C and maintained at this temperature for 15 minutes, the resulting crystalline substance is pale yellow, filtered off, washed with distilled water and ethanol, dried in vacuum at room temperature. is 0.2567 g, or 99.9%, and 99.92% of the total.

Found,%: Mo 24.4; C 47.6;

H 3.3.

Calculated,%: Mo 24.1; C 48.2;

H 3.5.

Example 3. Obtaining Mo _2. (0 ₂ CCH3) ^.

Javescu (NHg) 5-Mo ₂ Clg Ή ₂ 0 (1 g) is placed in a flask containing 30 ml of an aqueous solution containing 0.9942 g of CHaCOONHij. The reagent ratio is 1: 8 (1 g). (PN05-Mo _g C1 ₉ 'H ₂ 0 - 0.9942 g (CH _a COONHi,). The mixture is vigorously stirred for 5 min. To complete the precipitation of the dimeric dimolybdenum tetraacetate, the solution with precipitate is cooled to 5 ° C and kept at this temperature 10 minutes The resulting yellow crystalline solid was filtered off, washed with distilled water and ethanol, dried in vacuo at room temperature, purity 90.90%, yield 0.6769 g (98.0%).

g) 30 ml

1.2508 g of example 2. Yield or 99.1%. Purity

34.0; C 17.0; Η 1.2;

Found,%: Mo 44.5; C 22.7; H, 2.3.

Calculated,%: Mo 44.8; C 22.4;

2.8.

Example 4. Obtaining

Mo ₂ (0 ₂ CCH _and C1). "

A weighed portion (NH ^) ^ Μο £ Ι ₉ · Н ₂ 0 (I place in a flask, where there is an aqueous solution containing monochloracetic acid, the ratio of the components is 1: 8.2. The mixture is vigorously stirred for 5 minutes. Next, the experiment is conducted as in the product of 0.8861 g of 99.8%.

Found,%: Mo

C1 25.8

Calculated,%: Mo 34.6; C 17.3; Η 1.4; C1 25.6.

Example 5. Obtaining MokhSSS ^ COO).,.

A weighed portion of 1 g (NH _h ) _{g of} Mo ₂ Cl ₉ · H ₂ 0 is placed in a flask where 30 ml of an aqueous solution containing 2 g of trichloroacetic acid is located, the ratio of components is 1: 8, the mixture is vigorously stirred for 3 minutes. Further experiments are conducted, as in example 2. Purity 99 ', 90%. Yield 1.3535 g (99.6%).

Found,%; Mo 23.2; C 12.0; C 50.1.

Calculated,%: Mo _: 22.8; C 11.4; 50.5.

Example 6. Preparation of Mo ₂ (O ^ CCH ^ A portion (1 g) of phenylacetic acid is dissolved by heating in 20 ml of distilled water, after complete dissolution of the acid, 1.1387 g (1,105- Μο ₂ Cig Ήί, Ο and the mixture is stirred vigorously for 5 minutes, the ratio of dimolybdenum chloride to acid is 1: 4. The resulting crystalline substance, pale yellow, is filtered off, washed several times with hot water and dried in vacuum at room temperature until a constant mass is established Yield 1.3737 g or 99.4%, purity 99.70%.

Found,%: Mo 27.1; C 53.0; H 4.0. Calculated,%: Mo 26.2; C 52.4;

H 3.8.

Thus, in the proposed method for producing a dimeric cluster molybdenum tetracarboxylate, a significant simplification is achieved, cheaper Cl

This process is intensified and intensified, the reaction takes place in one stage at room temperature, there is no need for an inert medium and strict control of the rate of temperature rise, ₅ which makes it possible to significantly simplify the equipment used. The process is completed in 15-20 minutes, instead of 8 hours according to the well-known, in addition, water is used as a solvent instead of expensive diglyme, which makes the process cheaper.

The proposed method allows to expand the range of carboxylate ligands used due to the possibility of introducing into the reaction not only carboxylic acids, but also their salts. The yield of the desired product increases from · 30-80% according to the known method to 98-99% according to the proposed product with a purity of 99.9%. '

Claims (2)

This invention relates to the field of chemistry and fine chemical technology of rare elements, in particular, to an improved method for producing dimeric cluster molybdenum tetracarboxylate, which can be used to produce molybdenum catalysts, as well as a starting material in organic and inorganic synthesis reactions. A known method for producing dimeric cluster molybdenum tetracarboxylate, in particular dimolybdenum tetraformate Mo (0, jCI-1) j, by reacting dimolybdenum tetraacetate with formic acid in an inert gas atmosphere for 1-1.5 hours. The result is a solution of yellow colors that are filtered in an inert gas atmosphere and then cooled to 12 hours in an inert medium too, taking care that the temperature does not drop by one or two degrees, since at 8 s the reaction mixture may freeze. A precipitate of the desired yellow product is separated from the cooled solution with a yield of 72% 1. A disadvantage of the known method is its limited use only for those carboxylic acids that exist in the temperature range (10-90 0) used in the liquid state, and their chemical properties are capable of replacing the acetate groups in the original MOj COjCCHj) (In addition, the multistage process for producing tetraformate is multistage, all operations, including filtration and long-term purification of the product, should be carried out in an inert atmosphere. Particularly The experimental complexity of this method lies in keeping the reaction solution for a long time exactly at 10 ° C and lowering it even by 2 ° C can lead to unsuccessful synthesis due to the freezing of the reaction mixture. The closest to the technical essence and the achieved result 38 to the proposed method is to obtain a dimeric cluster molybdenum tetracarboxylate by reacting molybdenum carbonnyl Mo (CO) d with a carboxylic acid or its anhydride in dimethyl efr of diethylene glycol (diglyme) when heated and this mixture in a flask, refluxed under an inert gas atmosphere for 8 hours. At the same time, the importance of a 30-fold excess of diglyme in relation to the amount of acetic acid, the use of carbon dioxide to create an inert medium, and the need for strict regulation the rate of rise in temperature over 1.5 hours with a total heating time of the reaction mixture of 8 hours 2. The disadvantages of this method are the need to maintain a high temperature, as well as the use of significant amounts (thirty times excess) expensive solvent-diglyme, duration (8 h) and multistage process, strict control of the rate of temperature rise and unstable yield of tetracarboxylate which varies from 30 to 80%, depending on the amount of secondary molybdenum derivatives formed during the oxidation of Mo (CO) b in the form of three nuclear complexes of molybdenum with acetate bridging groups. The purpose of the invention is to simplify and intensify the process, increase the yield of the target product and expand the range of target products. This aim is achieved in that according to the method for producing di-, dimensional cluster tetracarboxylate molybdenum as molybdenum source Cpd Neny use dimeric cluster dimolibdena chloride, preferably KtsModSTs, (NHi) j MOjtClg, (NHj,) 5Mo2ClgN O, and subjecting it to react with carboxylic acid or its salt, taken in a molar ratio of 1: (4-12), in a medium of water. In this case, the reaction proceeds according to the following reaction scheme: ЧMozCl + RCOONH), MoiCOiCR) + 4НН (, 8c and the reaction is carried out for 15–20 mi. The initial chlorine-containing salt of dimolybdenum is dissolved with vigorous stirring in an aqueous solution of the acid or its salt, and After 5 min, a precipitate of dimeric cluster molybdenum tetracarboxylate is formed, which is characterized by very low solubility in water. For complete precipitation, the reaction mixture can be cooled in a refrigerator for 10-15 minutes. Dimeric cluster output quantitative molybdenum etracarboxylate (an attempt to determine molybdenum in the mother liquor did not lead to positive results.) The purity of the obtained product is 99.97%. The choice of reaction conditions, in particular, reactions in aqueous solutions, is due to the following reasons. Mo derivatives, | C1 and Mo C 1 / dissolve in water and can exist in aqueous solutions without destroying the metal-metal bond for 4 hours. This forms an intermediate aqua complex that promotes further interaction with the carboxylic acid. If the reaction is carried out directly with a carboxylic acid in the absence of water, the dimeric cluster tetracarboxylate of molybdenum is not formed or is formed with a low yield, and is not released in the solid phase. In addition, water, as a necessary component of the reaction, allows the number of carboxylic acids used to be expanded due to the interaction with their salts. The selected ratios of the starting components 1: 4-12 are due to the following. When the ratio of dimeric cluster molybdenum chloride: carboxylic acid or its salt is less than 1: 4, along with the main process, hydrolysis reactions take place and the yield of the target product decreases. When the ratio of components is greater than 1:12, conditions are created in the reaction mixture for the coprecipitation of the carboxylic acid or its salt, and the purity of the desired product deteriorates. The process of obtaining dimeric cluster molybdenum tetracarboxylate consists in the formation of an intermediate aqua-chloro complex of dimolybdenum, obtained by dissolving the MoS of the subsequent interaction of de, and the intermediate complex, in which the molybdenum-molybdenum bond is preserved, and the patterns are also shared by the dispatch patterns and the dispatch patterns and the dispatch body of the dispropies of the pendants and the staff of the staff of the team and the staff of the team and the other body of the staff of the staff of the team and the other body of the staff and the other of the staff of the staff of the other body of the staff and the staff of the staff of the team and the staff of the dispropies and the staff of the staff of the staff of the dispropies of the staff of the dispropies of the staff of the dispropies of the dispropies of the dispropies of the dispropies of the dispropies of the dispropies of the pendants. for the dissociation of the acid or its salt. Example 1. Getting Mo (NSOO) ,, Нз, 0. A weighed portion (1 g) is placed in a conical flask, where 40 ml of a 0.5 N aqueous solution of HCOGNHi is located. The ratio of KiiMojClg: NSOOMNts 1; 12. The mixture is stirred at room temperature for 5 minutes and separated off with a bright yellow product by filtration, washed with two portions of distilled water, then with ethanol and dried under vacuum at room temperature. Purity according to chemical analyzes and IR spectroscopy is 99.90%; Found,%; But 48.5; C 11.7; H 1.4. Calculated,%; Mo 49.4; C 12.3; H 1,, 2. Example 2. Obtaining Mo (OHCCH (OH) -CgH5) i, is a derivative with mandelic acid (H mind). A weighed amount of (NN4) Hj.D (0.2 g) is placed in a flask, where 20 ml of an aqueous solution containing O, 2452 mandelic acid, the ratio of initial reagents 1: 5, are located. Stir the mixture vigorously for 5 minutes. For complete precipitation of dimmer cluster dimolybdenum teramide daline, the solution with sediment is cooled to and kept at this temperature for 15 minutes. The pale yellow crystalline substance formed is filtered off, washed with distilled water and ethanol, and dried under vacuum at room temperature. The yield of the product is 0.2567 g or 99.9%. Num tota 99.92%. Found,%; Mo 24.4; C 47.6; H 3.3. Calculated,%: Mo 24.1; C 48.2; H 3.5. Example 3. Preparation) j ,, A yavescu (NH.,) 5-Mo, C1c, (1 g) is placed in a flask where there are 30 ml of an aqueous solution containing 0.9942 CHaCOONHij. The ratio of reagents 1: 8 (1 g). (NH) 5-MOjCl9 - 0.9942 g (CHjCOONHv). The mixture was vigorously stirred for 5 minutes, the precipitation of dimeric dimolybdenum tetraacetate was completely precipitated, the solution with the precipitate was cooled to 5 ° C and maintained at this temperature for 10 minutes. The resulting yellow crystalline substance is filtered off, washed with distilled water and ethanol, and dried in vacuo at room temperature. Purity 90.90%. The product yield of 0.6769 g (98,0%). 8 0 Found: Mo 44.55 C 22.7; N. 2.3. Calculated,%: Mo 44,8; C 22.4; H 2.8. Example 4. Getting MOj. (OiCCH ,, Cl),. A portion of (NH,) jMo, pl,. (1 g) is placed in a flask, where there are 30 ml of an aqueous solution containing 1.2508 g of monochloroacetic acid, the ratio of the components is 1: 8.2. The mixture is vigorously stirred for 5 minutes. Next, the experience lead, as in example 2. The product yield is 0.8861 g or 99.1%. Purity 99.8%. Found,% j Mo 34.0; C 17.0; H 1,2; C1 25.8. Calculated,%: Mo 34,6; C 17.3; H 1.4; C1 25.6. Example 5. Preparation of Mo5, (SCCRW) c. A weighed portion of 1 g (NH c), - Mo C1, -N, .0 is placed in a flask containing 30 ml of an aqueous solution containing 2 g of trichloroacetic acid, the ratio of the components is 1: 8, and the mixture is vigorously stirred for 3 minutes. Next, the experience lead, as in example 2. Purity 99,90%. The yield of 1.3535 g (99.6%). Found,%: Mo 23.2; C 12.0; C C1 50.1. Calculated,%: Mo.22,8; C, 11.4; C1 50.5. EXAMPLE 6: Preparation of Moj (OjCCHj Ce sH) A suspension (1 g) of phenylacetic acid is dissolved by heating in 20 ml of distilled water, after complete dissolution of the acid, 1.1387 g (MP) are added to this solution in portions. ,) 5-ОЗС1д-HaiG and the mixture is vigorously stirred for 5 minutes. The ratio of dimolybdenum chloride to acid is 1: 4. The crystalline substance of pale yellow color is filtered off, washed several times with hot water and dried in vacuo at room temperature until set. constant mass. The yield of 1.3373 g whether 99.4%. Purity 99.70%. Found,%: Mo 27.1; C 53.0; H 4.0. Calculated,%: Mo 26.2; C 52.4; H 3.8. Thus, in the proposed method of obtaining dimeric cluster molybdenum tetracarboxylate, a significant simplification, cost reduction and intensification of the process is achieved, the reaction takes place at room temperature in one stage, there is no need for an inert environment and strict control over the rate of temperature rise, which significantly simplifies the equipment used . The process is completed in 15-20 minutes, instead of 8 hours, according to the known, besides, water is used as a solvent instead of expensive diglyme, which reduces the cost of the process. The proposed method allows the range of carboxylate ligands to be expanded due to the possibility of introducing into the reaction not only carboxylic acids, but also their salts. The yield of the desired product increases from -30-80% by a known method to 98-99% according to the proposed product with a purity of 99.9%. The method of obtaining molybdenum dimeric cluster tetracarboxylate by reacting an inorganic molybdenum compound with a carboxylic acid or its derivative, characterized in that, in order to forgive and intensify the process, increase the yield of the target product and expand the range of target products, use dimeric cluster for the molybdenum compound. dimolybdenum taken in a molar ratio with a carboxylic acid or its salt, taken as a derivative of the acid, equal to 1: (4- 12) and the interaction is carried out in a medium of water. Sources of information taken into account in the examination 1.F. A. Cotton and others. The preparation and crystal structure of dimolybden tetuaformate; photoelectron spectra of dimolybdenum tetraearboxylates. J. Coord. Chem. vol 5, pp. 217-223, 1976. 2.J. Holstre und H.Sehafer. Moj. (CH4COO) i,, Moa. (CeH5-COO), und tMofiClg) Clj (CHjCOO) 391.263-270, 1972 (prototype). Z. anorg. allg.chem.