HYDROCARBON SOLUBLE DIALKYLMAGNESIUM COMPOSITION

Abstract: Hydrocarbon soluble compositions comprising at least three dialkylmagnesium compounds, in which at least two of said compounds contain straight-chain alkyl groups having from 1 to 4 carbon atoms each, and at least one additional compound contains alkyl groups having from 5 to 20 carbon atoms each.

Description: HYDROCARBON SOLUBLE DIALKYLMAGNESIUM COMPOSITIONS This invention relates to hydrocarbon soluble dialkylmagnesium compounds. Diorganomagnesium compounds are well known for their usefulness in a wide variety of chemical reactions. As reagents, these compounds can be used for the reduction of ketones, the metalaticn of aromatic cCirL pounds, and the alkylation of metal halides or oxides to the corresponding metal alkyls. As catalysts, diornanomagnesium compounds are useful in the dimerization and polymerization of olefins, see British Pat. 1,251,177; the polymerization of epoxides, see U.S. Pat. 3,444,102; and the prepara tion of telomers, see U.S. Pat. 3,742,077. T nile they perform many of the same types of fur.ctions performed by Grignard reagents, diorgancmagnesium compounds, owir.g to differences in electronic and steric factors, are more reactive than Grignard reagents toward certain types of compouds. In general, see also U.S. Patents 3,646,231 and 3,822,219. The utility of diorganomagnesium compounds is lessened by the fact that many are either solids or highly viscous liquids and all are unstable on exposure to moisture and air. This problem is generally over come either by dissolving the compound in an inert hydrocarbon solvent or by solvating the compound and by handli under an inert atmosphere. Many diorganomagnesium compounds, particularly those with straight chain lover alkyl groups with a chain length of up to four carbon altars, are insoluble by thernselves in hydrocarbon solvents and thus require solubilizing agents which will form a soluble complex. Examples of such solubilizing agents are alkyllithium compounds, see U.S. Pat. 3,742,077; dialkyl zinc corn pounds, see U.S. Pat. 3,444,102; alkali natal hydrides, see U.S. Pat. 3,655,790; and organoaluminum compounds, see U.S. Pat. 3,737,393. Solvaticn involves the use cf an ether or an organic base mole cule to associate directly with the magnesium atom, thus rendering a liquid-phase complex. The solvated form is undesir-cle, however, since salvation seriously inhibits the effectiveness of the compound, particu- larly when the compound is used as a Ziegler-type catalyst. The use of ether is particularly undesirable due to considerations of flammability and explosibility, and because it introduces soluble RMGX according to the Schlenk equilibrium EMI2.1 where R is alkyl and X is halogen. Solubilization also serves to reduce the viscosity of reaction mixtures use high viscosity muld otherwise inhibit the progress of the reaction and cause difficulty in handling and transferring. This problem is only partially solved by the use of chloroaryl solvents to form low viscosity suspensions of the insoluble compounds, as described in U.S. Pat. 3,264,360. In addition, the insolubility of the lower alkyl magnesium corn pounds makes preparation of them in a form free of undesirable halides difficult. In particular, the direct reaction of magnesium metal with an organic halide is disclosed in Glaze and Selman, Journal of Orqanar.etallic Chemistry, Viol. 5, p. 477 (1966), and W.N. Smith, Journal of Organo- metallic Chemistry, viol. 64, p. 25 (1974). These articles deal with the preparation of diorgagnesium compounds having straight chain alkyl groups of 5 carbon atoms and higher. Such compounds are soluble in hydro- carbon solvents and thus separable from the concurrently produced magnesi- an halide and unreacted magnesium. ten lower straight chain alkyls are used in this process, the desired diorganomagnesium compound is formed but is insoluble ard exists as a slurry in the solvent together with the may nesiun halide and unreacted magnesium metal. Thus a solubilizing agent is required when this process is used to make lower alkyl diorganomagnesium compounds. The latter are particularly desirable as reagents and catalysts owing to their relatively high magnesium content on a weight basis. Other methods of preparation include the mercury-magnesium exchange method, as disclosed in Cowan and usher, Journal of Orcanic Chemistry, %1. 27, p. 1 (1962), and the dioxanateprecipitation method, as disclosed in Schlerk, Berichte der Deutschen Chemischen Gesellschaft, Vol. 64, p. 734 (1931). The mercury method, EMI3.1 where R is alkyl, is limited by the high cost of dialkylmercury compounds, and the 'neSlth hazards involved in their use. The reaction itself Is hazardous since it proceeds rapidly and exothermically after an inhibition period. The dioxanate-precipitation method, EMI3.2 where R is alkyl and X is halogen, involves removal of magnesium halide from ether solutions of Grignard reagents by precipitation of a complex which the dioxane forms with the halide. This is a tedious process and results in an etherated dialkylmagnesium complex from which the ether must be removed prior to use as a catalyst. Dialkylrragnesiums can also be prepared from alkyllithiums, see U.S. Pat. 3,646,231, by precipitation of lithium halide, EMI3.3 where R is alkyl and X is halogen. This process is unsuitable for straight-chain lower dialkylmagnesiums which are insoluble in hydrocarbon solvents, since separation will be impossible. The use of basic solvents renders separation possible but requires subsequent desolvation. This reference also discloses the use of a hydrocarbonsoluble diorgananagnesium to solubilize an insoluble diorganomagnesium. The solubilizing mernbers shown in this reference, however, invariably contain branched chain alkyl groups. Such branched-chain diorganomagnesiur! compounds cannot be prepared by the Glaze and Selman method mentioned above. This fact is estab lished in the work of Vmienski and Eastham, Journal of Organic Chemistry, Vol. 34, p. 1116 (1968). Thus, resort to the lithium halide precipitation method is required. A similar process is described in U.S. Pat. 3,742,077. Again, the solubilizing agent must be a hydrocarbon soluble secondary-branched dialkylmagnesium such as d 1-tert-butylmagne slum or di-seabutylmagnesiwn. The general insolubility of straight chain lower alkyl magnesium compounds is thought to be due to intermolecular association resulting in the formation of a polymier-type macro-structure wherein each magnesium atom is tetrahedrally surrounded by four alkyl groups. Knows methods of solubilizing these compounds presumably operate to break sori:e of the intermolecular bonds and thereby break down the macro-structure into smaller units. Salvation or complexing as described above are thought to bring about this effect. Alkylmagnesiun compounds containing either branched-chain alkyl groups or straight chain alkyl groups of five carbon atoms or more, known to be effective as solubilizing agents, are also thought to operate by breaking the intermolecular bonds. With alkylmagnesium compounds, how- ever, the effect is thought to occur by way of alkyl interchange ard re-assocation, whereby the solubilizing alkyl groups exchange positions with some of the straight-chain lower alkyls. Polymerization is thus sterically hindered, either because the substituted groups are unwieldy for a tetrahedral fit around the magnesium atom, or because the groups have same inherent solubility of their own. U.S. Patent 4,069,267 discloses the use cf longer chain dialkylmagnesium compounds to stabilize (prevent precipitation of) di-n-butyl- magnesium/di-sec-butylmagnesium and di-n-butylmagnesium/di-tert-butyl- magnesium compositions. The longer chain dialkylmagnesium compounds have 6 carbons or greater in the alkyl groups, preferably S or 10 carbons. The process involves the use of relatively expensive branched-chain alkyl lithium compounds such as sec-butyllithium and tert-butyllithium, which are added to the reaction product of n utyl chloride with magnesium metal in the presence of a higher alkyl chloride. Though brandRd-chain dialkylmagnesium compounds (such as di-sec utyl and di-tertutyThiasium) are kraown to be highly soluble in hydrocarkon solvents and serve as highly effective solubilizing agents for insoluble dialkylmagnesium compounds (such as di-n-butylmagnesiun), these branched-chain magnesium alkyls cannot be made by direct reaction of the corresponding secondary or tertiary alkyl halide with magnesium metal in hydrocarbon media. Also, the three-component magnesium alkyl compositions disclosed in U.S. Pat. 4,069,267 contain two dialkylmagnesium compounds that are independently soluble in hydrocarbon solvents; hence it is not surprising that the three-component systems are highly soluble in such solvents. Several other U.S. patents disclose hydrocarbon soluble dialkylmagnesium systems containing tT or three components in which the alkyl groups are C1C4 straight-chain alkyl any the alkyl groups in the different dialkylmagnesium compounds differ by more than one carbon atom. U.S. Patent 4,127,507 describes such compositions comprising di-n-butylmagnesiwn and diethylmagnesium. U.S. Patent 4,207,207 describes such compositions comprising di-n-propylmagnesium and dimethylmagnesium. U.S. Patent 4,222,969 discloses such compositions comprising di-n-butylmagnesium and dimethylmagnesium. U.S. Patent 4,207,207 also describes a three-component hydrocarbon soluble magnesium alkyl system comprising di-n-propyl-, diethyl- and dimethylmagnesiums. Hou7ever, yields of soluble dialkylmagnesium in this three-component system were relatively low, at most about 25%. Additionally, when mrking with two-component lower alkyl magne- sium compositions as described in these three patents, it has been found that best results in terms of percentage yield of a hydrocarbon soluble dialkylmagnesium composition are obtained within relatively narrow ranges of mole ratios of the starting two alkyl halides. Thus, in U.S. Patent 4,127,507 it is shown from the disclosure, and particular.ly from Examples 2-8, that the greatest yield of soluble dialkylmagnesium composition is obtained with a mole ratio of nbutyl : ethyl chloride of between about 0.8:1 and about 1.25:1, and particularly at approximately equimolar ratios. On the other hand, when the mole ratio is varied to about 3:1 in favor of either n-hutyl or ethyl chloride, the yield of soluble dialkylmagnesium drops to about one-half of that at the optimum ratio, ard decreases to only a few percent yield at ratios of approximately 10:1 in favor of either chloride. Similar performance occurs with combinations of di-propyl/dimeLhyl and di-n-butyl/dimethyl magnesiums. Furthermore, U.S. Patent 4,222,969 also discloses (Examples 3-5) that when two dialkylmagnesium compounds differ by only one carbon atom in the alkyl groups, a hydrocarbon soluble composition is not obtained. In some instances, depending on the process in which a hydrocarbon soluble dialkylmagnesium composition is to be utilized, it may be acivantageous to prepare such a compos it ion dominating in ore of the two alkyl groups. kr instance, if the dialkyimagnesium compound is to be utilized as an alkylating agent in a hydrocarbon solution environment, it would be preferable to obtain a hydrocarbon soluble composition high in the desired alkylmagnesium. In production of certain polymerization catalysts, it may also be desirable to have a dialkylmagnesium composition high in one or another dialkylmagnesium of such a two-component composi- tion. If the objective is to obtain a hydrocarbon soluble dialkylmagne- sium composition with a high magnesium content, it would be preferable to have such a composition predominatly comprising the dialkylmagnesium with a smaller alkyl group. It is also desirable to provide a process for the production of such compositions. Summary of the Invention According to this invention, there is provided a composition comprising three or more diaLkylrgr.esiuxa compounds wherein between about 75 and about 95 mole percent of said composition comprises two or more dialkylmagnesium compounds in which the alkyl groups are each straightchain alkyl having from 1 to 4 carbon atans (hereinafter "lower dialkylmagnesium compounds"), and between 5 and 25 mole percent comprises at least one dialkylmagnesium compound having straight-chain alkyl groups containing 5 cr nsore carbon atoms (hereinafter "higher dialkylmagnesium compounds"). In a preferred anbodiment, the composition comprises two different lower dialkylmagnesium compounds in which the tuber of carbon atoms in the alkyl group of one compound differ fran that in the other compound by at least one carbon atom, the combined total of these two lower dialkylmagnesium compounds being between about 75 and about 95 mole percent of the overall composition, and at least one higher dialkylmagnesium corn pound in which the alkyl groups are straight-chain alkyls having 5 <RTI ID=6.50> carbon atoms or greater. In a more preferred composition, one of the two lower alkyl dialkylmagnesium compounds comprises between about 70 ard about 93 mole percent of the composition, the other lower alkyl dial'lmagnesium co-,- prises between about 2 and about 20 mole percent, and the higher dialkylmagnesium component comprises between about 5 and about 25 mole percent of the overall composition. In the most preferred composition, one of the tm lower dialkylmagnesium compounds comprises between about 70 and about 90 mole percent of the composition, and the other, between about 5 and about 20 mole percent. Detailed Description of the Invention The present invention pertains to dialkylmagnesium compositions comprising three or more dialkylmagnesium compounds, which compositions are soluble in hydrocarbon solvents. Preferably, such compositions contain three dialkylmagnesiums -- two lower dialkyl compounds and one higher dialkyl. The term "hydrocarbon solvents is used herein to designate aliphatic, cycloaliphatic, and aromatic hydrocarbons. Illustrative of aliphatic solvents are n-pentane, isopentane, n-hexane, n-heptane, n-octane, isooctane, pentamethylheptane, and gasoline and other petroleum fractions. Illustrative of cycloaliFX;atic solvents are cyclohexane, methylcyclo- hexane, methylcyclopentane, cycloheptane, and cyclooctane. Illustrative of aromatic solvents are benzene, toluene, xylenes, ethylbenzene, tetralin, and inethylnaphthalene. Preferred solvents are those containing 5 to 20 carbon atoms, inclusive. More preferred are those containing 6 to 15 carbon atoms, inclusive. Particularly preferred solvents are those which have boiling points between about 69 C and about 1100C. The concentration of dialkylmagnesium in the solvent is not critical and the compounds are generally soluble over a wide range of concentration. The solution viscosity increases with concentration, however. For greater ease of handling, therefore, the dialkylmagnesium concentration is normally fran about 0.2 to about 15.0 weight percent, ard preferably from about 1.0 to about 5.0 weight percent, in terms of magnesium. However, if the solution has a higher dialkylmagnesium concentration, its viscosity can be reduced as mentioned below. A number of techniques may be utilized for producing solutions of the multiple component dialkylmagnesium compounds in the desired hydrocarbon solvent. In one type of process, the solution is prepared by physically combining the diallylmagnesium compounds as such with the hydrocarbon solvent. The diallylmagnesium compounds may be utilized in their relatively pure form, or as solids or slurries resulting fran their manufacture. When utilized in either fashion, the dialkylmagnesium compounds may be in their individual states, (for instance, an insoluble form of di-n-butyl- magnesium, an insoluble form of diethylmagnesium and solid di-n-hexylmagnesium) or two or more of the dialkylmagnesiums may have been prepared in combined form which is mixed according to the invention in a hydrocarbon solvent with a higher dialkylmagnesium, such as di-n-hexylmagnesium. A clear solution results which is separable from any insolubles retained with the compounds. Thus, for instance, di-rtylmagnesium, as a solid or slurry, existing in admixture with magnesium halides, other insoluble by-products of the manufacturing process, or unreacted starting materials, can be contacted with a hydrocarbon solvent in the presence of, for instance, diethylmagnesium and, for instance, di-¯hexylmagnesium, to produce a solution containing the dialkylmagnesium compounds as solutes, substantially free of the other ingredients. Solubilization can be hastened by heating the solution to a temperature of about 50 C or higher. The rate of solubilization increases as the temperature is raised. Once the compounds are dissolved, they will remain in solution on any subse- quent lowering of temperature. If desired, separation of the solution from the remaining undis- solved solids can be enhanced by the use of any of the variety of viscosity reducing agents known in the art. Examples of such viscosity reducing agents are organoalurninum compounds such as trialkylaluminu:rs, dialkylaluminum halides and alkylaluminum dihalides. Alternatively, the dialkylmagnesium compounds can be prepared directly in the solvent in a common vessel by either simultaneous or sub- sequent reactions. My reaction is suitable in zilch neither the byproducts nor the unreacted starting materials are soluble in the final mixture. The insoluble can thus be easily filtered off. Cne such technique involves the direct reaction between metallic magnesium and the appropriate alkyl halides. The concurrently produced magnesium chloride forms a precipitate which is readily removed from the solution together with any unreacted magnesium still present. Another technique involves the use of a Grignard reagent to supply one alkyl group. The Grignard reagent is preferably freed of all ether used in its preparation prior to its use in the present reaction. The desired solution of dialkylmagnesium compounds is then obtained by reaction of the desolvated Grignard reagent with the reaction product of the other alkyl halides with magnesium metal. When magnesium is reacted directly with an alkyl halide, commer- cial grade magnesium turnings or shavings can be used. It is preferable, however, to use a form of magnesium with a higher surface area than either of the above. This can be accomplished by milling, but it is most preferable to use the metal in a finely divided state, for instance, as a powder with a particle size equal to or less than about 150 microns. If the magnesium is to be reacted sequentially with the appropriate halides, it is preferable to first react the magnesium with the alkyl halide containing the greatest number of carbon atoms, that is an alkyl halide which contains straight-chain alkyl groups of 5 or more carbon atoms, then with the alkyl halide having the next higher nurrber of carbon atoms and so on, down to the alkyl halide having the fewest number of carbon atoms. A magnesium activating agent may be employed to initiate the reaction. Because the higher alkyl halides are more reactive with magnesium than the lower alkyl halides, some care should be taken to prevent an uncontrolled reaction. This may be achieved, for instance, by utilizing a large amount of solvent, extra agitation, a slow rate of alkyl halide addition, or further addition of excess magnesium. The term "magnesium activating agent" is used herein to denote heat or any substance which, when contacted with magnesium, will cause the magnesium to react with the alkyl halide at a substantially faster rate. Many activating agents are known in the art. typical examples are AlCl3, A1C13-ether complexes, N,N-dimethylaniline, molecular iodine, alkyl halides of at least 3 carbon atoms, and Grignard reagents. A small quantity of a higher alkyl dialkylmagnesiun, such as di-nhexylmagnesitr. itself can serve as an activating agent, as wrentioned in U.S. Pat. 4,207,207, Example 2. Thermal activation may also be utilized, and is generally performed at tempe.-atures between about 1250C and about 350 C, preferably fran about 1500C to about 250 C, and most preferably from about 1500C to about 200 C. Once the magnesium is activated, the magnesiurtvalkyl halide reaction can proceed at lower temperatures. Although reaction can occur over a wide temperature range once the magnesium is activated, it will be most convenient to operate between about 80 C and about 130 C. At least 10% by weight of alkyl halide based on the weight of magnesium metal must be present during thermal activation. The temperature ranges quoted above are not critical to any of the reactions. The minimum temperature is dictated largely by process econanics, while the maximum temperature is limited only by the possibili of alkyl halide decomposition ard considerations of energy conserva tion. Preferably, the compositions are manufactured by a process in i.idh the various alkyl halides are reacted simultaneously, in the desired roportions, with the magnesium. Alternatively, the higher al.rwl halide s first contacted with the magnesium, and then the remaining alkyl halides are added as a mixture. Following any of the above procedures, the solids can be removed fran the reaction mixture by any conventional technique, for example, centrifuging, decanting, or filtration. The resulting solution of dialkylmagnesium compounds can then be diluted or concentrated to give the concentration desired for purposes of reactivity, viscosity, or economic considerations. The term "halide" as used herein denotes chloride, bromide, or wide, or combinations thereof. Chlorides are generally preferred for reasons of economy. The mole ratio of magnesium to alkyl halide can be varied over a wide range. No particular range is critical to the performance of any of the reactions. Normally, however, the starting materials will be such that the mole ratio of magnesium to total halides is fran about 1.0 to about 2.0, preferably from about 1.1 to about 1.3. The excess magnesium inherent in mole ratios greater than 1.0 is effective in minimizing Wurtz coupling reactions. The hydrocarbon solvent may be added before, during, or after the reaction. It will be most convenient to add the solvent prior to or during the reaction of the first added alkyl halide with magnesium so that further reaction is less inhibited by viscosity. Magnesium alkyls are pyrochoric substances, capable of spontaneous ignition upon contact with air. To prevent such ignition, ard also to prevent oxidation of the dialkylmagnesiums, the reactions must be carried out in the absence of more than trace amounts of oxygen. Thus, the reactions are normally carried out in an atmosphere of inert gas such as nitrogen or argon, or in an atmosphere of an alkyl halide gas. The reactions must also be conducted in the substantial absence of water, due to the reactivity of dialkylmagnesiums with water. The pressure under which the reactions are conducted is not critical and pressures ranging fran atmospheric to elevated pressures of several atmospheres can be employed. The reactions will be most conve- niently run at least in slight excess of atmospheric in order to keep the alkyl halides in solution. The preferred pressure range is about 8 psig (1.6 x i05 pascals) to about 100 psig (8.0 x 105 pascals). The lower dialkylmagnesium compounds in the compositions of this invention contain straight-chain alkyl groups having fran 1 to 4 carbon atoms each. Ex & ples of such compounds are dimethylmagnesium, diethyl magnesium, di-n-propylmagnesium, i-n-butylmagne s ium, and combinations of alkyl magnesiums such as n-butylethylm gnesiurn, n-propylmethylmagnesium, methylethylmagnesiun, and the like. The compositions of the present invention contain at least two of such lower dialkylmagnesiums. The higher dialkylmagrlesivas contain straight-chain alkyl groups of 5 carbons or greater, preferably 5 to 20 carbon atoms and most preferably, 5 to 12 carbon atotns. Examples of such compounds are di-n-amylmagnesium, di-n-hexylmagnesium, di-n-octylmagnesium and the like. In these compounds, the two alkyl groups are preferably identical. The hydrocarbon soluble compositions of this invention in general contain a total of from about 75 to about 95 mole percent of lower dialkylmagnesium compounds (tm or more such ccfr.pourlds) and frcm about 5 to about 25 mole percent of at least one higher dialkylmagnesium compound. Preferably, the compositions will predominate in a selected lower dialkylmagnesium compound, and will contain from about 70 to about 93, most preferably 70 to about 90, mole percent of one lower dialkylmagnesium com- pound, from about 2 to about 20, most preferably from about 5 to 20, mole percent of a second lower dialkylmagnesium compound, and from 5 to about 25 mole percent of a higher dialkylmagnesium. For instance, a composition according to this invention containing diethyl-, di-n-butyl-, ard di-n- hexyl magnesiums, could have as little as 5 mole percent di-nhexylmagne- sium and as much as 93 mole percent of either di-n-butyl- or diethylmagneslum, with the other lower dialkylmagnesium being present in as little as 2 percent. bst preferably, for use as a polymerization catalyst, the composition will contain a high amount of di-n-hutylmagnesium and a lower amount of diethylmagnesium. The compositions according to this invention may contain lower dialkylmagnesiums which differ only by one carbon atom in the alkyl groups. Such corrbinations would inciude for instnce, dimethyl/diethyl magnesiums, d i-n-propyl/d i-n-butyl magnesiums or d iethyl/d i-n-propyl magnesiums. As shown in Examples 3-5 of U.S. Patent 4,222,969, two- com- ponent compositions containing only these types of dialkylmagnesiums were insoluble in hydrocarbon solvents. The present invention, however, provides for the first time hydrocarbon soluble compositions containing mmbinations of such dialkylmagnesiums with no other metal present. The invention is further illustrates by the following examples EXAMPIF 1 (Comparison Example) This example denstrates the production of a mixture of dimethyl and diethyl magnesiums according to the prior art, and corresponds to Example 5 of U.S. Patent 4,222,969. A pressure bottle equipped with a variable diptube, thermowell and stirrer was immersed in an oil bath, purged with nitrogen and charged with 13.0 grams (g) (0.53 g-atom) of magnesium po -der. A small amount (0.24 g) of di-n-hexylmagnesium was added to activate the metal and take up any moisture present, together with 184 g of heptane, and the bottle was heated to 100-110 C. While this temperature was maintained, 13.3 g (0.21 mole) of ethyl chloride was added slowly over a period of two hours. Following the ethyl chloride addition, the system temperature was raised to 130-136 C and methyl chloride was added in a quantity of 6.6 g (0.13 mole) over a pericd of to hours. The reaction mixture was then held at 1300C for six hours. The solids in the reaction mixture were then allowed to settle and the clear hydrocarbon phase was sampled. Analysis of the sample indicated only 0.03 weight percent magnesium, or about 1.5% of theoretical yield. The solids were then solubillzed by the addition of tri-n-octylaluminum. Analysis of the resulting solution indicated 0.83 weight percent magnesium, or about 40% yieid, with a methane:ethane mole ratio of 0.3:1 in the hydrolysis gas, indicating that both dimethylmagnesium and diethylmagnesium had been made as an insoluble mixture. EXAMPLE 2 Production of a Composition Comprising Dimethvl-, Diethyl- and Di-amyl Magnesiums Using the apparatus ard general procedure described in Example 1, the following alkyl chlorides were charged to the pressure bottle, in the order and relative mole percent listed: n-amyl chloride (1996), ethyl chloride (1996), methyl chloride (62%). Analysis of the viscous supernatant liquid showed a magnesium content of 1.18%, corresponding to a yield of soluble magnesium alkyls of 41 %. Analysis of the volatile hydrocarbons resulting from hydrolysis showed 43% methane, 35% ethane, and 22% n-pen three. The calculated amount of magnesium in this soluble dimethyl/ diethyl/di-n-amyl magnesium composition is 27.4%. The lower dialkylmagnesiums in this composition comprise 81 mole percent, and the di-n-amylmagnesium, 19 mole percent. EXAMPLES 3-7 Following the same procedure described above, the following experiments were performed using mixtures of ethyl, n-butyl and n-hexyl chlorides, and for comparison, mixtures containing only ethyl and n-butyl chlorides. In all such mixtures, the mole ratio of ethyl:n-butyl chlorides ranged from 1:3 up to 1:18, that is, quite disproportionate as compared to the preferred ratio of 1:1 in U.S. Patent 4,127,507. As can be seen frum the results, addition of relatively small amounts of n-hexyl chloride (ranging from 5 to 13 mole percent) resulted in substantially higher yields of soluble magnesium alkyl as ccomared to experiments without nhexyl chloride. Mole % Alkyl Chloride Charged Ethyl n-Butyl n exyl Yield of Soluble Exarrple No. Chloride Chloride Chloride Magnesium alkyl, 96 3 (ooaarison) 27 73 0- 38 4 (invention) 12 75 13 76 5 (comparison, II 89 0 5 6 (invention) 5 90 5 68 7 (invention) 2 92 6 70 Thus, in Example 5 for instance, an attempt to make a dialkyl- magnesium composition containing di-n-butyl and diethyl magnesiums at a mole ratio of approximately 8:1 produced only a 5% yield of soluble magnesium alkyls without the addition of a higher alkyl compound. However, as shown by Example 6, the inclusion in the reaction mixture of only 5 mole percent n-hexyl chloride resulted in the production of a good yield of a hydrocarbon soluble dialkylmagnesiun composition containing a very high content (90 mole %) of di-rutylmagnesium.

Claims: CLAIMS: 1. A composition of matter soluble in hydrocarbon solvents con- prising at least tm lower diaikylmaanesian compounds in which the alkyl groups are straight-chain alkyls containing from 1 to 4 carbon atoms each, and at least one higher dialkylmagnesil3n compound in which the alkyl groups are straight-chain alkyls containing from 5 to 20 carbon atoms each. 2. A composition according to Claim 1 in which the alkyl groups in the higher dialkylmagnesium compounds contain from 5 to 12 carbon atoms each. 3. A composition according to Claim 1 comprising tm lower dialkylmagnesium compounds having from 1 to 4 carbon atoms in the alkyl groups and one higher dialkylmagnesium cowound having from 5 to 12 carbon atoms in the alkyl groups. 4. A composition according to Claim 1 containing di- > amylmag- nesium. 5. A composition according to Claim 1 containing di-n-hexylmagnesium. 6. A composition according to Claim 1 containing diethylmagnesium and di-n-butylmagnesium. 7. A composition according to Claim 6 containing di-n-hexylmagnesium. 8. A composition according to Claim 3 in which the t lower dialkylmagnesium compounds differ by one carbon atari in the alkyl groups. 9. A composition according to Claim 8 comprising dimethylmagnesium and diethylmagnesium. 10. A composition according to Claim 1 comprising from about 75 to about 95 mole percent lower dialkylmagnesium compounds and from about 5 to about 25 mole percent of one or more higher dialrz aagr.siwa compounds. 11. A composition according to Claim 2 comprising fran about 75 to about 95 mole percent lower dialkylmagnesium compounds and fran about 5 to about 25 mole percent higher dialkylmagnesium compounds. 12. A composition according to Claim 3 comprising from about 70 to about 93 mole percent of a first lower dialkylmagnesium compound, from about 2 to about 20 mole percent of a second lower dialkylmagnesium com pound and fran about 5 to about 25 mole percent of a higher dialkylmagne- sium compound having from 5 to 12 carbon atoms in the alkyl groups. 13. A composition according to Claim 12 comprising fran about 70 to about 90 mole percent of a first lower dialkylmagnesium compound, fran about 5 to about 20 mole percent of a second lower dialkymagnesium compound arld from about 5 to about 25 mole percent of a higher dialkyl- magnesiun compound having from 5 to 12 carbon atoms in the alkyl groups. 14. A process for the manufacture of a hydrocarbon solution of a composition comprising dialkyLmagnesiun. compounds which comprises: (a) reacting, in the presence of a hydrocarbon solvent, magne- slum metal, with an alkyl halide in which the alkyl group is a straightchain alkyl having from 5 to 20 carbon atoms; (b) either simultaneously to step (a) or subsequent thereto, reacting, in the presence of the solvent of step (a), further magnesium metal, with an alkyl halide in ich the alkyl group is a straight-chain alkyl having from 1 to 4 carbon atoms; ; (c) either simultaneously to steps (a) and/or (b) or subsequent tireto, reacting with further magnesium metal, a second alkyl halide in which the alkyl group is a straight-chain alkyl having from 1 to 4 carbon atoms, to form a mixture of a hydrocarbon solution containing dialkylmag- nesiun compounds and undissolved solids; and (d) separating the hydrocarbon solution fran the undissolved solids, all steps being conducted in the substantial absence of both .!oistuMe and oxygen. 15. A process according to Claim 14 in which the hydrocarbon solvent is a meddler selected frcn the group consisting of aliphatic, cycloaliphatic and aromatic hydrocarbons containing 5 to 20 carbon atoms, inclusive. 16. A method according to Claim 14 in which the alkyl halides are alkyl chlorides. 17. A method according to Claim 14 in which step (a) is conducted in the presence of a magnesium activating agent. 18. A method according to Claim 14 in which steps (a), (b), and (c) are conducted at tarr.ratures of fran about 80 to about 1300C. 19. A method according to Claim 14 in which the ratio of the alkyl halide utilized in step (a) to the sum of the alkyl halides utilized in steps (b) and (c) is from about 1:18 to about 1:3. 20. A composition of matter comprising: (a) a first dialkylmagnesium compound in which the alkyl groups are straightahain containing from 1 to 4 carbon atoms (b) a second dialkylmagnesium compound in which the alkyl groups are straight-chain containing from 1 to 4 carbon altars; (c) at least one further dialkylmagnesium compound in which the alkyl groups are straight-chain containing from 5 to 20 carbon atoms; and (d) a solvent selected from the qroup consisting of aliphatic, cycloaliphatic, and aromatic hydrocarbons containing 5 to 20 carbon atoms inclusive. 21. A composition according to Claim 20 in which the alkyl groups of compounds (c) are straight-chain containing from 5 to 12 carbon atoms. 22. A composition according to Claim 20 in which the components (a), (b) and (c) are present in respective molar zT.ounts of: from about 70 to about 93 mole percent of (a), from about 2 to about 20 mole percent of (b), and from about 5 to about 25 mole percent of (c). 23. A composition according to Claim 22 in which the components (a), (b) and (c) are present in respective molar amounts of: from about 70 to about 90 mole percent of (a), from about 5 to about 20 mole percent of (b), and fran about 5 to about 25 mole percent of (c). 24. A composition according to Claim 20 in which component (a) is di-n-butylmagnesium, component (b) is diethylmagnesiurn, and component (c) is di-n-hexylmagnesiL'rn.

Inventors: FANNIN, LOYD WAYNE, MALPASS, DENNIS BENEDICT, SANCHEZ, RAMIRO
Applicants: TEXAS ALKYLS INC.
Application year: 1984
Main classification: C07F3
IPC codes: C07F3