Metal-magnesium compounds, process for preparing same and the use thereof for the preparation of finely divided metal and alloy powders and intermetallic compounds

Abstract: The present invention relates to metal-magnesium compounds, a process for preparing same and the use thereof, especially for the preparation of finely divided, possibly amorphous, metal and alloy powders and/or of intermetallic compounds, both procedures via a non-metallurgical route in organic solvents under mild conditions.

Description: The present invention relates to metal-magnesium compounds, a process for preparing same and the use thereof, especially for the preparation of finely divided, possibly amorphous, metal and alloy powders and/or of intermetallic compounds, both procedures via a non-metallurgical route in organic solvents under mild conditions. Metal alloys and/or intermetallic compounds are usually prepared by metallurgical processes. Metal powders in a finely divided highly reactive form are obtained according to DE 35 41 633 (Studiengesellschaft Kohle, 1987) by reacting metal salts in a solvent with magnesium powder which has been admixed with a catalytic amount of anthracene and/or of magnesium anthracene or one of the derivatives thereof as an acivator. According to the DE 36 13 532 (Studiengesellschaft Kohle, 1987) there has been known a process for the preparation of finely divided, possibly amorphous, intermetallic compounds and the hydrides thereof, wherein hydrides of the elements of the Main Groups I to IV of the Periodic Table, hydridemagnesium halides or magnesium dialkyls in an organic solvent are reacted with bisallylmetal compounds of the metals of the Subgroup VIII of the Periodic Table or of zinc. A recently described method for the preparation of finely divided metal and alloy powders {H. Bönnemann et al., Angew. Chem. 102 (1990), 324} consists of the reduction or co-reduction of metal salts in an organic phase by means of alkali metal or alkaline earth metal organohydridoborates. Now, surprisingly a new process as given in claim 15 was found for the preparation of metal-magnesium compounds (M 1 -Mg-compounds) of the formula M 1 -Mg-halide of M 1 -hydride-Mg-halide, and by employing these, of metal and alloy powders or of intermetallic or metal-element compounds (M 1 , M 1 M 2 , M 1 M 2 M 3 ...) in a finely divided highly reactive and possibly amorphous form. The invention relates to new M 1 -Mg-compounds which are soluble in tetrahydrofurane (THF). Said M 1 -Mg-compounds are produced by a reaction in which halides of the metals of the Groups VB-VIIB, VIII, IB and IIB of the Periodic Table (M 1 X m ), or optionally the metals M 1 or M 1 -hydrides, are reacted in an organic solvent with a molar excess of magnesium hydride (MgH 2 ), hydridemagnesium halides (HMgX), organomagnesium compounds and/or metallic magnesium, if desired in the presence of anthracene or its derivatives, magnesium anthracene · 3 THF (MgA) or its derivatives, magnesium halides, organic halides and/or quinuclidine as activators. Tetrahydrofurane (THF) is deemed to be the preferred solvent wherein at least one of the M 1 -component or the Mg-component containing a halide ion,. The metals M 1 are preferred to be employed in a finely divided highly reactive form, while it is desirable that the magnesium component used has preferably been dissolved or partially dissolved in an organic solvent, or that an insoluble magnesium component (e.g. magnesium powder) is employed in the presence of said activators. As the MgH 2 , there is preferably employed the catalytically prepared MgH 2 (MgH 2 *; European Patent 3564, Studiengesellschaft Kohle, 1982) or the catalytically prepared dissolved MgH 2 (MgH 2 '; DE 37 22 993, Studiengesellschaft Kohle, 1989). As the preferred organomagnesium compounds, there are contemplated C 1 -C 12 -alkylmagnesium halides, di-C 1 -C 12 -alkylmagnesium compounds, MgA or its alkyl or aryl derivatives and/or Mg 2 Cl 3 (THF) 6 ⊕ -anthracene ⊖ . The invention further relates to specific compounds as given in claims 3 to 14 and to the use of said M 1 -Mg-compounds as defined in claims 23 to 25. It is considered a pre-requisite for the preparation of M 1 -Mg compounds from metal halides M 1 X m according to the present invention that an excess of the magnesium compound is employed relative to the quantity required for reducing M 1 X m to the metal level M 1 or to form a M 1 hydride. Namely, in this procedure, part of the Mg component is consumed for the reduction or M 1 X m to the metal stage or for the formation of M 1 hydride, whereas the excess of the Mg-component reacts with the metal M 1 or with the M 1 hydride in statu nascendi to form the M 1 -Mg compound. Therefrom it ensues that in the reaction of M 1 X m with the Mg component, depending on the molar ratio of M 1 X m :magnesium component and on the reaction conditions, both M 1 or M 1 hydride, M 1 -Mg compounds in admixture with M 1 or M 1 hydride and M 1 -Mg compounds alone may be formed. Nevertheless, the preparation of M 1 -Mg compounds may also be carried out in two steps, if so desired, wherein first M 1 X m , with the Mg component, is reduced to the metal level M 1 or converted into the M 1 hydride, and then the resulting M 1 or M 1 hydride, which is present in a finely divided highly reactive form, is subsequently reacted with a further amount of the Mg component in a solvent, or in the solid state by means of a subsequent thermal treatment, to form the M 1 -Mg compound. In the reaction of M 1 X m (or of M 1 ) with the Mg components mentioned according to the present process, the types a.-d. listed hereinbelow of M 1 -Mg compounds may be formed, depending on the kind of M 1 X m (or of M 1 ) and of the Mg component and on the molar ratio and reaction conditions employed: a. intermetallic Mg compounds or Mg alloys (Mg x M 1 y ); b. intermetallic Mg hydrides (Mg x M 1 y H p ), carbides (Mg x M 1 y C q ) and hydride-carbides (Mg x M 1 y H p C q ); the M 1 -Mg compounds listed in a. and b. comprise known compounds of the respective types as well as compounds hitherto unknown. It is characteristic for the instant process that the resulting compounds are formed in a highly reactive, finely divided and possibly X-ray amorphous form. Of special novelty is the finding that according to the present process there can be formed not only solid intermetallic Mg compounds or Mg alloys, but in many cases also the hitherto unknown THF-soluble M 1 -Mg compounds, namely the THF-soluble M 1 -Mg halides (Type c.), and the THF-soluble M 1 -Mg (hydride)halides (Type d.). It has further been found that the Mg in the M 1 -Mg compounds preparable according to the present process may be replaced by an alien metal or element M 2 or by two or more alien metals or elements (M 2 , M 3 ... ) by allowing M 1 -Mg compounds to react with M 2 halides (M 2 X n ) or with a mixture of M 2 and M 3 halides, preferably in a solvent. Thus, in combination with the method presented for the preparation of M 1 -Mg compounds of the types a. through d., for the first time there ensues a purposeful two-step synthesis of intermetallic compounds as well as metal-element compounds or metal alloys (M 1 M 2 , M 1 M 2 M 3 , ...), under mild conditions ("cold metallurgy") and without employing the otherwise conventional, expensive metallurgical processes. The preparation of (M 1 M 2 ) in accordance with this two-step synthesis may be described by the following equations: 1 st Step: M 1 X m + Mg component → M 1 -Mg compound + m / 2 MgX 2 Optional 1 st Step: M 1 * or M 1 hydride + Mg component → M 1 -Mg compound 2 nd Step: M 1 -Mg compound + M 2 X n → (M 1 M 2 )↓ + n / 2 MgX 2 If so desired, the preparation of (M 1 M 2 ) according to this method may be carried out also in one step (Example 22a) by allowing to react M 1 X m with the magnesium component in the presence of M 2 X n . For the preparation of M 1 M 2 , M 1 M 2 M 3 according to the presented method there may also be employed the M 1 -Mg compounds preparable according to the DE 36 13 532 (Studiengesellschaft Kohle, 1987). If, according to the presented method, the M 1 -Mg compounds are reacted with M 1 X m , then the metals M 1 are obtained in a finely divided highly reactive form: M 1 -Mg compound + M 1 X m → 2 M 1 *↓ + m / 2 MgX 2 The preparation of the M 1 -Mg compounds a. through d. and the use thereof for the production of metal and alloy powders and of intermetallic compounds (M 1 , M 1 M 2 , M 1 M 2 M 3 ) is furnished evidence of by the Examples 1 through 41, while it is not limited thereto. Examples for the preparation of M 1 Mg compounds according to Equation 1 have been set forth in the Tables 1 to 4 and 4a, and examples for the preparation of metal alloys (M 1 M 2 ) according to Equation 2 and of the metal powders (M 1 *) acording to Equation 3 have been set forth in the Tables 5 and 5a. The soluble or insoluble M 1 -Mg compounds preparable according to the instant process may be used as, inter alia, homogeneous or heterogeneous catalysts, as starting materials for the preparation thereof or for the preparation of organometallic M 1 compounds. Thus, for example, the Mg-Sn, Mg-Pb and Mg-Ga alloys accessible according to the process may be employed as starting material for the preparation of organotin compounds (herbicides, pesticides), organolead compounds (knock inhibitors) and organogallium compounds (Ga, As, photovoltaic cells). The intermetallic Mg hydrides (compounds of type b.) and especially the THF-soluble M 1 -Mg (hydride)halides (type d.) such as, e.g., Fe(HMgCl) 2 (Example 21) may be used as reducing agents for functional organic compounds such as, e.g., esters, ketones, aldehydes, halides and the like. The solid M 1 -Mg compounds may find use as metal and alloy powders in the powder technology (e.g. Mg 2 Cu), and the hydrides and carbides thereof may find use as reversible hydrogen and heat storage media, where it is an advantage that according to the instant process they are obtained in a highly active, finely divided and often X-ray amorphous form. Besides, the M 1 -Mg compounds according to Equations 2 and 3 are employed as starting materials for the preparation of metal and alloy powders (M 1 , M 1 M 2 , M 1 M 2 M 3 , ...) in a finely divided, highly reactive form. The metal and alloy powders (M 1 , M 1 M 2 , ...) are also usable in powder technology and especially as heterogeneous catalysts (e.g. FeCu, Example 21, as catalyst for the Fischer-Tropsch synthesis). The advance in the art constituted by the instant process is also due to the fact, besides other reasons, that intermetallic M 1 -Mg compounds and alloy powders (M 1 M 2 , ...) have become accessible which according to the hitherto common metallurgical procedures could be produced not at all or only at a higher expenditure. Thus, for example, the intermetallic compound Mg 2 Pd (Example 12) which reversibly reacts with hydrogen is hardly ever accessible via a metallurgical route. The new intermetallic compounds, the tetragonal MgPt and Mg 2 Pt could not be produced via the metallurgical route. Figure 1 shows a powder diagram of Mg 2 Pt measured with a sample of Example 17. Also shown for comparison are the calculated diagrams for Mg 2 Pt and MgPt. It is evident that the examined sample contains both compounds. Figure 2 shows a powder diagram of MgPt measured with a sample of Example 18. Also shown for comparison is the calculated diagram for MgPt. It is evident that the examined sample consists of only one compound. - EXAMPLES - The experiments were carried out in an argon atmosphere; THF was distilled over diethylmagnesium or magnesium anthracene · 3 THF (MgA). The data of Examples 1 to 6 are shown in Table 1. EXAMPLE 1 To a stirred solution/suspension of 6.94 g (16.6 mmoles) of MgA in 50 ml of THF there was dropwise added at room temperature (RT) within 1 hour a solution of 1.56 g (8.2 mmoles) of anhydrous SnCl 2 dissolved in 50 ml of THF, whereupon a black suspension formed. After stirring at RT for 1 hour, a 2 ml sample of the suspension was protolyzed with 2 ml of a mixture of toluene:CH 3 OH, 25:1, (using n-C 16 H 34 as internal standard) and analyzed by gas chromatography (GC), whereafter the batch contained 15.4 mmoles of anthracene and 0.3 mmoles of 9,10-dihydroanthracene. In the deep-blue THF solution, 9.4 mmoles of Mg 2+ and 0.01 mmole of Sn were analyzed by complexometric analysis. The suspension was filtered, and the solid was washed with THF until the washing liquid was colorless. After drying under vacuum (0.2 mbar), there were obtained 1.17 g of a black pyrophoric solid which had the composition Mg 12.4, Sn 60.5, C 1.9, H 0.3% (Mg:Sn = 1:1). After hydrolysis (H 2 O + 5N H 2 SO 4 ) of a sample of the solid and GC analysis of the organic portion, the solid contained 0.03%of anthracene. According to the X-ray powder analysis the solid was a mixture of the intermetallic Mg compound Mg 2 Sn with elemental Sn. The preparation of the mixture of Mg 2 Sn* + Sn* was repeated in the same manner and with the same amounts as described above and was confirmed by X-ray powder analysis of an isolated small sample of the solid. The still moist solid left after filtration was suspended in 50 ml of THF, the stirred suspension was admixed with a solution of 8.2 mmoles of SnCl 2 in 47 ml of THF, and the mixture was stirred at RT for 7 hours. The suspension was filtered, the solid was washed with THF and dried under vacuum (0.2 mbar). According to the X-ray powder analysis, only Sn, but no Mg 2 Sn, is present in the solid. EXAMPLE 1a (COMPARATIVE EXAMPLE TO EXAMPLE 1) To a cooled and stirred solution or suspension of 6.45 g (15.4 mmoles) of MgA in 50 ml of THF there was added all at once a solution of 3.20 g (16.9 mmoles) of anhydrous SnCl 2 in 50 ml of THF; thereupon the temperature of the reaction mixture rose from 13 °C to 25 °C, and a black solid precipitated. During the subsequent stirring of the batch at RT, samples (of 2 ml) of the solution were taken, and by complexometric titration it was determined that the deposition of tin was completed already after about 3 minutes. After this time, upon the hydrolysis of the sample, a molar ratio of anthracene:9,10-dihydroanthracene of 30:1 was determined. The suspension was filtered, the precipitate was washed twice with 30 ml of THF each and dried under vacuum (0.2 mbar). 1.34 g of a black powder were obtained which had the composition of Sn 96.8, Mg 1.2, Cl 0.4% and a specific surface area of 16.2 m 2 /g. EXAMPLE 2 The experiment was carried out and worked up in the same manner as in Example 1 while, however, the SnCl 2 solution was added all at once to the MgA suspension. After a period of reaction of 18 hours at RT, 29.0 mmoles of Mg 2+ and only traces of Sn 2+ were detected in the solution. EXAMPLE 3 A. Preparation of Mg 2 Sn from SnCl 2 and MgA: To a stirred solution or suspension of 14.8 g (35.3 mmoles) of MgA in 100 ml of THF there was added at -60 °C a solution of 1.69 g (8.9 mmoles) of SnCl 2 in 50 ml of THF. The resulting black suspension was allowed to warm up from -60 °C to -30 °C within 12 hours, from -30 °C to RT within 12 hours, and was stirred at RT for further 12 hours. The suspension was filtered, and the solid was washed seven times with a total of 330 ml of THF, until the initially blue washing liquid running off was colorless. After drying under vacuum (0.2 mbar) there were obtained 1.65 g of a black pyrophoric powder having the composition of Mg 25.59, Sn 64.14, C 5.44, Cl 1.27, H 0.97%. According to the X-ray powder analysis the powder was amorphous; it had a specific surface area of 109.4 m 2 /g. This Mg 2 Sn failed to give any reflections in the X-ray powder diagram even when tempered at 250 °C for 4 hours. B. Preparation of Mg 2 Sn from SnCl 2 and MgA, followed by the reaction with CuCl 2 to form a Cu-Sn alloy: To a stirred solution or suspension of 19.0 g (45.4 mmoles) of MgA in 150 ml of THF there was added at -78 °C a solution of 13.1 mmoles of SnCl 2 in 70 ml of THF; the resulting black suspension was allowed to warm up to RT within 6 hours, and was then stirred at RT for 4 days (cf. the preparation of Mg 2 Sn* described in A. ). Once the Mg 2 Sn* had settled, the yellow supernatant solution was siphoned off, 50 ml of THF were added to the Mg 2 Sn*, the resulting suspension was stirred for 30 minutes, and the solution again was siphoned off. This operation was repeated two more times. Then Mg 2 Sn* was suspended in 100 ml of fresh THF, the suspension was admixed with 3.48 g (25.4 mmoles) of anhydrous CuCl 2 and was stirred at RT for 82 hours. The black suspension was filtered, the solid was washed 4 or 5 times with THF and was dried under high vacuum. Obtained were 3.18 g of a Mg-containing Cu-Sn alloy which had the composition set forth in Table 5. In the filtrate of the batch, there were found 20.6 mmoles of Mg 2+ by way of an analysis. In addition to weak reflections caused by Sn, the alloy showed numerous reflections in the X-ray powder diagram which could not yet be assigned. EXAMPLE 4 SnCl 2 was added as a solid material to the suspension of MgA in 170 ml of toluene. After 4 hours of stirring, 28 mmoles of anthracene and 0.4 mmoles of 9,10-dihydroanthracene were found to be present in the solution. Prior to the filtration, the mixture was stirred another 18 hours at RT and 2 hours at 50 °C. EXAMPLE 7 A stirred suspension of 16.70 g (40.0 mmoles) of MgA in 100 ml of THF was admixed at -70 °C with a solution of 43.3 moles of SnCl 2 in 176 ml of THF; the mixture, while stirred, was allowed to warm up to RT within 6 hours, and was then stirred for 66 hours at room temperature. A sample of the solid (0.94 g) was isolated and identified as elemental Sn by X-ray powder analysis and elemental analysis (Sn 97.85, Mg 0.57, C 0.44, H 0.11, Cl 0.74%). The clear supernatant solution was siphoned off from the remaining batch, 200 ml of THF were added to the Sn*, the suspension was stirred for 10 minutes, and the solution was again siphoned off. This operation was repeated two more times. Sn* was then suspended in 200 ml of fresh THF, 21.5 g (51.7 mmoles) of solid MgA were added to the suspension, and the mixture was stirred at RT for 1 h. The black suspension was filtered, the solid was washed with THF and dried under vacuum (0.2 mbar). Obtained were 4.29 g of Mg 2 Sn* (in admixture with little Sn*), which was identified by means of an X-ray powder analysis; elemental analysis: Sn 72.49, Mg 20.78, Cl 0.59, C 2.82, H 0.43%. EXAMPLE 8 A solution cooled at 0 °C of 16.2 mmoles of SnCl 2 in 87 ml THF was added to 5.72 g (14.8 mmoles) of MgA, and the black suspension was stirred at RT for 21 hours (cf. Example 1a). The supernatant solution was siphoned off; 60 ml of THF were added to the Sn*, the resulting suspension was stirred for 30 minutes, and the solution was again siphoned off. A small portion of Sn* (about 50 mg) were dried under vacuum and analyzed: Sn 92.86, Mg 0.22, C 0.74, H 0.16%; in the X-ray powder diagram, the Sn* sample is identical with an authentic sample of Sn powder. The remainder of Sn* was suspended in 10 ml of THF and added to a mixture comprising 0.62 g (25.7 mmoles) of Mg powder (270 mesh), 0.25 g (1.4 mmoles) of anthracene, and 16 ml of a 0.53 molar MgCl 2 solution in THF (8.5 mmoles of MgCl 2 ), which mixture in advance had been stirred at RT for 3 hours to form the deep-blue complex [Mg 2 Cl 3 · 6 THF] ⊕ -anthracene ⊖ . After 17 hours of stirring, the suspension was gray-violet, and the solution was deep-blue in color. The suspension was filtered, Mg 2 Sn* was washed 3 or 4 times with THF and was dried under vacuum (0.2 mbar). Obtained were 1.75 g of Mg 2 Sn* as a black powder of the composition Sn 71.91, Mg 25.82, Cl 0.39, C 1.26, H 0.23%. The X-ray powder diagram of the Mg 2 Sn* thus prepared conforms to that of the JCPDS data file (except for two low-intensity reflections). In the dark-blue tin-free filtrate there were found 1.04 mmoles of anthracene and 0.14 mmoles of 9,10-dihydroanthracene by GC analysis. The data relating to the Examples 9 to 16 are shown in the Tables 2, 2a and 5. EXAMPLE 9 A suspension of 1.11 g of MgH 2 (76.5% according to thermovolumetric analysis; 32.2 mmoles of MgH 2 ), prepared by catalytic hydrogenation of magnesium [Cr catalyst, RT; Angew. Chem. 92 (1980) 845] in 60 ml of THF was stirred at RT and portionwise admixed with 2.89 g (16.3 mmoles) of anhydrous PdCl 2 , and the resulting suspension was stirred at RT for 24 hours, whereupon 0.67 H 2 /Pd were released. Upon heating the suspension at 60 °C for 6 hours until the H 2 evolution ceased, the amount of hydrogen evolved increased to 0.92 H 2 /Pd. The suspension was filtered while still warm, and the solid was subsequently washed with THF. After drying in vacuum (0.2 mbar), 2.10 g of an X-ray amorphous solid were obtained which had the composition of Pd 73.74, Mg 19.07, C 3.19, H 1.86, Cl 2.21% (Mg 1.13 PdC 0.38 H 2.66 Cl 0.09 ). In the filtrate of the batch there were titrimetrically determined 17.0 mmoles of Mg 2+ and 29.5 mmoles of Cl - . A sample of 1.59 g of the solid was heated from RT to 400 °C at a rate of 1 °C/min; in the course thereof, in the temperature range around 317 °C, corresponding to the decomposition temperature of MgH 2 , 224 ml of a gas (20 ° C/1 bar) were obtained which had the composition of H 2 95.1, CH 4 1.2, C 4 H 10 3.7%. After hydrogenation under pressure (20 bar/200 °C/24 hours), the sample was once more subjected to thermolysis as described above, whereupon only 26 ml of gas were formed. After this operation, the sample failed to absorb any H 2 in a hydrogen atmosphere at 102 °C under normal pressure, according to which finding the presence of finely divided metallic palladium is to be excluded. Due to the broad reflections at d = 2.230 (100), 3.161 (38.9), 1.822 (25.7), and 1.289 (25.0) in the X-ray powder diagram, the sample contains the cubic MgPd known from the literature (P.I. Kripyakevich, E.I. Gladyshevskii, Kristallografiya 5 (1960) 552; CA 13641, 1962), however not any free Mg or Pd. [After annealing a small portion of the sample (690 °C/72 hours/argon), the cubic MgPd was converted into the tetragonal Mg 0.9 Pd 1.1 (X-ray powder reflections at d = 2.2550 (100), 2.1395 (34.2), 3.0264 (25.6), and 1.2555 (23.9)]. Upon a renewed pressure hydrogenation, the sample failed to yield virtually any gas as described above and exhibited the reflections of the tetragonal Mg 0.9 Pd 1.1 in the X-ray powder diagram, but no reflections of free Mg or Pd. Composition of the sample after the operations described: Pd 78.65, Mg 17.61, C 1.18, H 0.78, Cl 1.58% (MgPd 1.02 C 0.14 H 1.07 Cl 0.06 ). EXAMPLE 11 38 ml of a 1.31-molar MgH 2 '-solution in THF (49.9 mmoles of MgH 2 '), prepared according to the DE-OS 37 22 993 (catalyst: 1% by mole of FeCl 2 -Mg-anthracene, 4% by mole of quinuclidine, 9% by mole of MgCl 2 ) were stirred and at -78 °C portionwise admixed with 2.57 g (14.5 mmoles) of anhydrous PdCl 2 . Then the batch with continuous stirring was allowed to warm up from -78 °C to RT within 3 hours, whereupon the evolution of H 2 began to occur at about -55 °C. The batch was stirred for further 42 hours at room temperature until the H 2 evolution ceased. Work-up and analysis were carried out as decribed in Example 9. Data on the experiment are shown in the Tables 2 and 2a. The resulting solid is the amorphous Mg-Pd carbide which is preparable also from MgH 2 ' and bis(η 3 -allyl)palladium {Zeitschr. Phys. Chem. N.F. 162 (1989) 191}. EXAMPLE 11a COMPARATIVE EXAMPLE TO EXAMPLE 11 If MgH 2 ' is reacted with PdCl 2 in a molar ratio of 1:1 in THF at room temperature, then after work-up there is obtained a finely divided, highly reactive Pd powder (Table 2), however not any Mg-Pd compound. EXAMPLE 12 59 ml of a 0.84-molar MGH 2 '-solution in THF (49.6 mmoles), prepared according to the DE-OS 37 22 993 were vigorously stirred and in a closed system at RT were portionwise admixed with 2.11 g (11.9 mmoles) of anhydrous PdCl 2 , so that the internal temperature did not exceed 30 °C. The H 2 evolution began immediately. After 1 hour of stirring at RT and development of altogether 1.13 H 2 /Pd (Gl. 17) the suspension was filtered. Work-up and analysis were carried out as decribed in Example 9. Data on the experiment are shown in the Tables 2 and 2a. The resulting solid is the reversible hydride Mg 2 PdH x (literature quoted in Example 11), as is concluded from the behavior in dehydrogenation/re-hydrogenation cycles and from the composition. EXAMPLE 13 To a stirred suspension of 2.48 g (14.0 mmoles) of the anhydrous PdCl 2 , dried under high vacuum, in 60 ml of THF at -78 °C there was added a solution cooled at -78 °C of 2.34 g (28.5 mmoles) of MgEt 2 in 50 ml of THF (the color turns to black!), and the suspension was subsequently stirred at the constant temperature for 48 hours. Then the vessel was connected to a gas burette, was then allowed with permanent stirring to warm up from -78 °C to RT within 2 hours and was then stirred at room temperature for another 48 hours. Then the volatile components were condensed under vacuum (0.2 mbar) in two cold traps connected in series (-78 °C and -196 °C). MS analysis of the quantities of the gases evolved during the warm-up period and at RT and present in the condensates yielded 2.02 C 2 H 6 /Pd and 1.77 C 2 H 4 /Pd. The residue was taken up with 100 ml of fresh THF, the suspension was stirred at RT for a short time, filtered, the precipitate was washed several times with THF and twice with pentane, and was dried under high vacuum. 0.25 g of a black powder are obtained, which has the composition as reported in Table 2. In the THF solution having a deep-brown color there were found by complexometric titration after hydrolytic work-up 28.8 mmoles of Mg 2+ , 28.6 mmoles of Cl - and by atomic absorption analysis 12.3 mmoles of Pd 2+ . To an aliquot of the Pd(MgCl) 2 solution prepared as described above (1.32 mmoles of Pd in 56 ml of THF) there were added 0.29 g (1.65 mmoles) of PdCl 2 , the suspension was stirred at RT for several days, centrifuged, and the resulting solid was washed with THF and dried under high vacuum. Obtained were 0.16 g of a solid, the composition of which has been set forth in Table 5. Another part of the Pd(MgCl) 2 solution (4.51 mmoles of Pd in 80 ml of THF) was admixed with the equimolar amount of SnCl 2 in THF (0.85 g, 4.50 mmoles of SnCl 2 in 10 ml of THF); the suspension was stirred at RT for 3 to 4 days, filtered, and the black, extremely fine precipitate was washed with THF. Upon drying under high vacuum there were obtained 1.02 g of an X-ray amorphous powder having the composition as indicated in Table 5. In the THF-filtrate of slightly brown color there were found by complexometric titration 8.8 mmoles of Mg 2+ and 17.6 mmoles of Cl - and by atomic absorption analysis 0.026 mmoles of Pd and 0.034 mmoles of Sn. The data of the Examples 16 to 20 are shown in the Tables 3, 3a and 5, the data of the Examples 21 to 27 are shown in the Tables 4 and 5a, and the data of the Examples 28 to 32 are shown in the Tables 4a and 5a. EXAMPLE 28 A suspension of 4.86 g (0.20 moles) of Mg powder (270 mesh) in 130 ml of tetrahydrofurane was subjected to an ultrasonic treatment for 1 3/4 hours; thereto, 2.53 g (19.9 mmoles) of FeCl 2 (anhydrous) were added, and the resulting mixture was again subjected to the ultrasonic treatment for 1 hour and then stirred at RT for 18 hours. An aliquot part of the suspension was centrifuged with 10,000 rpm for 1 hour to remove Mg and Fe* from the solution. The determination of the amount of hydrogen evolved upon protolysis of an aliquot of the clear deep-blue solution and of the iron dissolved therein (13.5% of the initial FeCl 2 amount) resulted in 1.52 H 2 /Fe. EXAMPLE 32 A suspension of 20.0 g (0.82 moles) of Mg powder (270 mesh), 1.78 g (10 mmoles) of anthracene and 0.2 ml (2.6 mmoles) of ethyl bromide in 100 ml THF were stirred for 2 to 3 hours until the formation of MgA was completed. To the stirred product, 1.97 g (10.2 mmoles) of NiCl 2 · 0.9 THF were added within two hours, the resulting mixture was stirred for 3 hours, filtered, and the filter cake was washed with THF. An aliquot of the clear black filtrate (113 ml) was hydrolyzed with 2N H 2 SO 4 , and the hydrogen formed thereupon (2.2 H 2 /Ni) was analyzed by mass spectrometry. A further sample of the filtrate was protolyzed with CH 3 OH which had been admixed with n-octane and n-hexadecane as internal standards; the sample was centrifuged (to remove the precipitated nickel), and the solution was analyzed by gas chromatography. The solution (113 ml) contained, according to the GC analysis, 1.0 mmole of n-butanol, 7.5 mmoles of 9,10-dihydroanthracene, 0.1 mmoles of anthracene, 0.2 mmoles of tetrahydroanthracene and 0.1 mmoles of 9-(4-hydroxybutyl)-9,10-dihydroanthracene and, according to the complexometric titration 6.6 mmoles of Ni 2+ , 27.2 mmoles of Mg 2+ and 17.0 mmoles of Cl - . Example 33 13.0 g (31 mmoles) of MgA is suspended in 50 ml THF. 50 ml of a 0.45 molar solution of GaCl 3 in THF is dropped over a period of 0.5 h into the stirred MgA /THF suspension previously cooled to -78 °C. The color of the suspension changes from orange to a dark brown-black. The suspension is allowed with stirring to warm up to room temperature over a period of ∼18 h to give a black suspension. The product, active Ga metal (Ga*), is allowed to settle on the bottom of the flask and the green or yellow colored supernatant is removed. The solid is washed with several additions of fresh THF until the supernatant is colorless. The metal can also be isolated by centrifuging the reaction slurry and, after washing, transferring the solid suspended in fresh THF to a Schlenk flask. 3.6 g (8.6 mmoles) of MgA are transferred at room temperature to the Ga*/THF suspension via 4-shaped bridge. The reaction suspension immediately turns green. After stirring at room temperature for 24 h, the product is allowed to settle out of the suspension (now dark grey or black colored), washed with several additions of fresh THF, and dried under high vacuum. Yield: 90 % of Mg 2 Ga 5 , obtained as a crystalline, black pyrophoric powder. Only the diffraction lines corresponding to Mg 2 Ga 5 (Acta Cryst. B 25, (1969) 554) are noted in the X-ray diffraction pattern. Example 34 9.21 g (22.3 mmoles) of MgA were suspended in 400 ml toluene and stirred at room temperature for 24 h yielding in a fine suspension of active magnesium (Mg*). A large proportion of the solvent toluene was removed by decantation, leaving ca. 40 ml of toluene with Mg* metal. After adding 100 ml of freshly distilled THF and 2.25 g (7.2 mmoles) of anhydrous BiCl 3 to Mg*/THF suspension, the reaction suspension was stirred for 48 h at room temperature. After filtration, washing with THF and pentane, and drying under vacuum, 1.80 g (97 %) of Bi 2 Mg 3 were obtained as a black pyrophoric powder having a specific surface area of 68 m 2 /g and containing ∼ 4 wt% of organic matter and 1.5 wt% Cl. The X-ray powder diagram of Bi 2 Mg 3 thus prepared exhibits, apart from two weak signals for Bi, only strong reflections for Bi 2 Mg 3 . Examples 35-37 Anhydrous metal chlorides (AuCl 3 , HgCl 2 and PbCl 2 ; Table 6) were added in the course of 5 min to the stirred suspensions of MgA in THF and the reaction suspensions stirred for the time given in the table 6. After filtration, washing with THF (until the final wash was colorless) and drying under vacuum, the magnesium intermetallics (table 6) were obtained as black or grey powders and identified by X-ray powder diffractometry. Example 38 NbCl 5 reacts with catalytically prepared magnesium hydride (US PS 4,554,153) in the molar ratio 1:5 in THF at room temperature with the evolution of 1.5 H 2 /Nb and formation of a THF-soluble complex of the composition Cl 2 Nb(HMgCl) 3 . After removing THF via vacuum distillation, the solid complex liberates upon thermolysis between 135 - 285 °C at ambient pressure gas with the composition H 2 69 % (0.8 H 2 /Nb), 12 % CH 4 , 5 % C 2 -, 6 % C 3 - and 8 % C 4 -hydrocarbons. Example 39 RhCl 3 reacts with MgEt 2 in the molar ratio 1:2 in THF at room temperature with evolution of 2.3 mole C 2 H 6 - and 1.5 mole C 2 H 4 /Rh and formation of a THF-soluble complex of the composition RhMg 2 Cl 3 . The latter reacts with SnCl 2 in the molar ration 2:1 in boiling THF with formation of a precipitate of a Rh-Sn-alloy Rh 2 Sn. Example 40 In the course of the reaction of IrCl 3 with MgEt 2 in the molar ratio of 1:3 in THF at room temperature, 2.3 moles C 2 H 6 , 1.2 mole C 2 H 4 and 0.3 mole C 2 H 2 /Ir are set free, while 1 mole of MgEt 2 remains unchanged. The clear THF solution contains an Ir-complex of the composition IrMg 2 Cl 3 analogous to the complex RhMg 2 Cl 3 of the example 39. Example 41 To a suspension of 1.06 g (34.1 mmoles) of catalytically prepared magnesium hydride (MgH 2 *, US PS 4,554,153) in 30 ml THF were added 1.58 g (7.5 mmoles) of anhydrous RhCl 3 and the suspension stirred for 22 h at room temperature resulting in the evolution of 1.2 mole H 2 /Rh. The precipitate was filtered off, washed with THF and dried in high vacuum affording 1.53 g of a solid. 1.14 g of the solid delivered on programmed heating (1 °C/min) to 400 °C at ambient pressure 291 ml gas composed of CH 4 and H 2 (62.9 %). The resulting solid was subjected to two hydrogenation/dehydrogenation cycles (1. cycle: hydrogenation at 30-40 bar H 2 /230-380 °C/71 h; dehydrogenation at ambient pressure r.t. - 400 °C, 1 °C/min, 118 ml H 2 . 2. cycle: hydrogenation at 25 bar H 2 /200 °C/24 h; dehydrogenation as in the first cycle, 98 ml of a 10:1 H 2 -CH 4 mixture) and thereafter annealed under argon at 550 °C for 20 h. The X-ray powder diffraction lines of the annealed sample can be assigned to a hitherto unknown intermetallic Mg 2 Rh having a tetragonal (a = 3.1914, b = 10.1054 Å) MoSi 2 structure type.

Claims: In tetrahydro furane (THF) soluble metal-magnesium compounds of the formula M 1 -Mg-halide or M 1 -hydride-Mg-halide, wherein M 1 represents a metal of the Groups VB-VIIB, VIII, IB and IIB of the Periodic Table produced by a reaction of metals M 1 ,M 1 -halides or M 1 -hydrides, in an organic solvent with a molar excess of a magnesium-containing compound selected from magnesium hydride (MgH 2 ), hydridemagnesium halides (HMgX), organomagnesium compounds and/or metallic magnesium, if desired in the presence of anthracene (A) or its derivatives, magnesium anthracene · 3 THF (MgA) or its derivatives, magnesium halides, organic halides and/or quinuclidine as activators, wherein at least one of the M 1 -component or the Mg-component contains a halide ion. The compounds according to claim 1, characterized in that organomagnesium compounds are C 1 -C 12 -alkylmagnesium halides, di-C 1 -C 12 -alkylmagnesium compounds, MgA or its derivatives and/or Mg 2 Cl 3 (THF) 6 + -anthracene - . The amorphous intermetallic compounds MgPt and Mg 2 Pt, prepared from PtCl 2 and undissolved MgH 2 * in a molar excess in THF and subsequent thermal treatment of the resulting Pt-MgH 2 being soluble in THF mixtures, the tetragonal MgPt 3 or the monoclinic Mg 2 Pt in admixture with the tetragonal MgPt, prepared by annealing amorphous MgPt or Mg 2 Pt. The amorphous 1:1 and 2:1 Mg-Pt hydrides being soluble in THF, prepared from PtCl 2 and dissolved MgH 2 ' in a molar excess in THF, and the monoclinic Mg 2 Pt and tetragonal MgPt resulting from the thermal treatment or annealing thereof. The tetragonal intermetallic compound MgPt, and the monoclinic intermetallic compound Mg 2 Pt. The amorphous MgCu-hydride being soluble in THF, prepared from CuCl 2 and dissolved MgH 2 ' in a molar excess in THF, and the intermetallic Mg-Cu compounds resulting from the thermal treatment thereof. The compounds THF-soluble Pd(MgCl) 2 and THF-soluble Pt(MGCl) 2 , prepared from PdCl 2 and PtCl 2 , respectively, and magnesium dialkyls or alkylmagnesium halides in THF. The compounds THF-soluble Pd(MgCl) 2 and THF-soluble Pt(MgCl) 2 . The compounds THF-soluble Fe(HMgCl) 2 , THF-soluble Co(HMgCl) 2 , and THF-soluble Ni(HMgCl) 2 , prepared from FeCl 2 , CoCl 2 and NiCl 2 , respectively, and dissolved MgH 2 ' in THF. The compounds THF-soluble Fe(HMgCl) 2 , THF-soluble Co(HMgCl) 2 , and THF-soluble Ni(HMgCl) 2 . The THF-soluble Ru, Rh and Mn hydridemagnesium chlorides, prepared from RuCl 3 , RhCl 3 and MnCl 2 , respectively, and MgH 2 ' in THF. The compounds THF-soluble Fe 2 Mg 3 Cl 4 and THF-soluble Ni 2 Mg 3 Cl 4 , prepared from FeCl 2 and NiCl 2 , respectively, and Mg powder, optionally in the presence of anthracene, quinuclidine or 1,2-dibromoethane as activators in THF. The compounds THF-soluble Fe 2 Mg 3 Cl 4 and THF-soluble Ni 2 Mg 3 Cl 4 . The compound THF-soluble Ni(MgCl) 2 · MgA, prepared from NiCl 2 and Mg powder in the presence of MgA (magnesium anthracene · 3 THF), wherein A is antracene. The method for the production of a metal-magnesium compound produced by reacting a metal M 1 of Group IIIA-VA, VB-VIIB, VIII, IB or IIB of the Periodic Table or a halide M 1 X m or hydride thereof in an organic solvent with a molar excess of at least one magnesium-containing member selected from the group consisting of magnesium hydride (MgH 2 ), a hydridemagnesium halide (HMgX), an organomagnesium compound, optionally in the presence of at least one activator selected from the group consisting of anthracene (A) or a derivative thereof, magnesium anthracene · 3 THF (MgA) or a derivative thereof, a magnesium halide, an organic halide and quinuclidine. The method according to claim 15, characterized in that tetrahydrofurane (THF) is used as solvent. The method according to claim 15, characterized in that metals M 1 or M 1 -hydrides are employed in a finely divided, highly reactive form. The method according to claims 15 and 17, characterized in that the magnesium component has been dissolved or partially dissolved in the organic solvent. The method according to claim 15, characterized in that the catalytically prepared undissolved (MgH 2 *) or the catalytically prepared dissolved MgH 2 (MgH 2 ') is employed as the MgH 2 . The method according to claim 15 or to claim 19, characterized in that the reaction of M 1 X m with the Mg component is carried out in two steps, wherein first M 1 X m is reacted with the Mg component to form M 1 or the M 1 hydride, and then the resulting M 1 or M 1 hydride is subsequently reacted with a further amount of the Mg component in a solvent, or in the solid state by means of a subsequent thermal treatment, to form the M 1 -Mg compound. The method according to claim 15, characterized by the production of metalpowders or alloys produced by a first step reacting metal M 1 or a halide or hydride thereof in an organic solvent with at least one magnesium-containing member selected from the group consisting of magnesium hydride (MgH 2 ), a hydridemagnesium halide (HMgX), an organomagnesium compound, optionally in the presence of at least one activator selected from the group consisting of anthracene or a derivative thereof, magnesium anthracene · 3 THF (MgA) of a derivative thereof, a magnesium halide, an organic halide and quinuclidine and in a second step reaction of such a compound with a M 1 halide. The method according to claim 21, wherein the metal M 1 in the second step is different than the metal M 1 in the first step. Use of the M 1 -Mg compounds according to claims 1 to 14 or produced according to claims 15 to 22 for the preparation of finely divided metal and alloy powders and of intermetallic compounds (M 1 , M 1 M 2 , M 1 M 2 M 3 ,...)by reacting same with metal or element halides (M 1 X m , M 2 X n , M 3 X o , ...). Use according to claim 23, characterized in that the reaction of M 1 Mg compounds is carried out in a solvent. Use according to claim 23 or 24, characterized in that the reaction of M 1 X m with the magnesium component is carried out in the presence of M 2 X n , M 3 X o ,... .

Inventors: BOGDANOVIC BORISLAV PROF, WILCZOK URSULA, BOGDANOVIC, BORISLAV, PROF., WILCZOK, URSULA
Applicants: STUDIENGESELLSCHAFT KOHLE MBH
Application year: 1991
Main classification: B22F9
IPC codes: C01G53, C01G49, B22F9, C22C23, C22C1, C01B6, C01G55, C01B31, C01G1