DE1181217B - Process for the production of dialkyl aluminum hydrides with alkyl radicals with more than 2 carbon atoms - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN -007WW PATENT OFFICE Internat. Class: C07f

EDITORIAL

German class: 12 ο -26/03

Number: 1181217

File number: C 32444IV b / 12 ο

Filing date: July 29, 1961

Opening day: November 12, 1964

The German Auslegeschrift 1 164 404 describes a process for the production of diethylaluminum hydride by reacting aluminum triethyl with aluminum and hydrogen at elevated temperatures and pressing, characterized in that an aluminum alloy is used that contains small amounts of titanium, vanadium, zirconium or niobium.

It has now been found that you can also dialkyl aluminum hydrides with alkyl radicals with more than 2 to 40 carbon atoms by reacting aluminum trialkyls with identical or different alkyl radicals with the exception of aluminum triethyl at elevated temperatures and pressures with hydrogen in the presence from aluminum can advantageously be obtained by using an aluminum alloy instead of aluminum used, which contains about 0.02 to 2 percent by weight of titanium, vanadium, zircon, niobium, scandium, Contains uranium or hafnium. The inventive use of aluminum alloys with catalytic amounts of other metals is more effective in the claimed reaction than the separate one Application of aluminum with the catalytic elements. According to the invention, the following were made Compounds: diisobutyl aluminum hydride, dioctyl aluminum hydride, dipentadecyl aluminum hydride, Didocosylaluminum hydride and ditetracontylaluminum hydride.

The added catalytically active elements have the following properties:

1. They form hydrides;

2. They are essentially suitable for the formation of peritectic binary systems with aluminum, And you are

3. Obviously electronegative towards aluminum, even if scandium, uranium and hafnium are usually classified differently compared to aluminum.

Experiments have shown, however, that not all elements that form a peritectic with aluminum such as barium, lanthanum and cerium, are alloy additives suitable according to the invention. Metal combinations can also be used are added to the aluminum.

It has been found that the effectiveness of the additional elements is different. For example, match 200 parts per million titanium, about 20 parts zircon in their reactivity when used in an alloy with 99.99% aluminum. The tables below show the lower limits of the Effectiveness of the catalytic elements according to the invention indicated.

Process for the preparation of dialkyl aluminum hydrides with alkyl radicals with more than 2 carbon atoms

Applicant:

Continental Oil Company,

Ponca City, Okia. (V. St. A.)

Representative:

Dr.-Ing. A. v. Kreisler, Dr.-Ing. K. Schönwald, Dr.-Ing. Th. Meyer,

Dipl.-Chem. Dr. rer. nat. J. F. Fues, Dipl.-Chem. Dr. H.-G. Eggert and Dipl.-Phys. I. Grave, patent attorneys, Cologne 1, Deichmannhaus

Named as inventor:

Frederick J, Radd,

Warren W ^ Woods, Ponca City, OkIa. (V. St. A.)

Claimed priority:

V. St. v. America September 26, 1960 (783 209)

Table 1 indicates the lower limits of the effectiveness of the catalytic elements when they are very high pure, 99.99% aluminum can be introduced.

Table 2 gives the lower limits of effectiveness of the catalytic 'elements when they are in an aluminum of about 99.4% purity, that is, commercially available Aluminum. '

Table 1

Lower limits of the effectiveness of the catalytic elements in 99.99% aluminum

45 Hafnium .... Suitable Preferably JHIcrncIlL titanium Parts per million Parts per million Zircon ...... niobium about 1,000 about 5,000 50 vanadium about 100 about 200 uranium about 5 about 20 Scandium .... about 1,000 about 5,000 about 1,000 about 2 500 about 200 about 1,000 about 200 about 2,000 409 727/474

Table 2

Lower limits of the effectiveness of the catalytic elements in 99.4% aluminum

Suitable Preferably Parts per million Parts per million hafnium about 2,000 about 10,000 titanium about 200 about 500 Zircon about 50 about 500 niobium about 5,000 about 10,000 Vanadium about 5,000 about 10,000 uranium about 600 about 1 200 Scandium about 400 about 1,000

In the tables above, the term "suitable" denotes the lower limit, which is an optical one Effect or a weight loss caused in the reaction described. The expression "preferably" denotes the lower limit that produces a technically important effect.

Theoretically there is no upper limit to the amount of the catalytic elements added. the end for practical reasons, however, it is generally not necessary to use more than 2 percent by weight of the add catalytic elements to the aluminum. Almost always 1 percent by weight is sufficient.

For each element there is a point at which the addition of larger quantities of this element to the Aluminum no longer significantly improves reactivity. Titanium or zircon are preferably added to the aluminum in amounts of 0.02, in particular only 0.05 percent by weight.

It has been found that iron, lithium, copper, tin, lead and nickel reduce the reactivity of aluminum with respect to the production of organoaluminum compounds. Iron, lithium, and copper are natural impurities in almost all aluminum that is is commercially available. For the purposes of the invention, these elements must be classified as "negative" elements because they reduce the effectiveness of the catalytic elements according to the invention. This negative effectiveness must be compensated for by an increased addition of catalytic elements will.

The process according to the invention therefore makes it possible, through the addition of catalytic Elements so-called inactive aluminum in active aluminum for the production of organoaluminum Convict connections.

As aluminum alloys alloys are referred to in the context of the invention, in which the catalytic elements alone or in combination were added to the aluminum. The addition can be done in any way. For example, by adding the elements directly to aluminum or by adding the catalytic elements or alloys or inorganic salts to the primary Electrolysis cell in which the aluminum is extracted. One can also use reducing compounds or add mixtures of the catalytic elements to the furnace.

The aluminum alloys used according to the invention contain at least 98% aluminum.

To produce the alloys according to the invention, aluminum alloys, the larger Contain proportions of the catalytic elements, mix with aluminum or aluminum alloys, which contain no or an insufficient amount of catalytic elements for activation. The form in which the aluminum alloys are used according to the invention is for what is claimed Procedure insignificant. Preferably

ίο one will use finely divided aluminum as possible. The conversion of the organoaluminum compounds and the hydrogen with the aluminum alloy usually takes place at temperatures between 80 and 200 ° C, preferably from 100 to 150 ° C, at pressures from 60 to 350 atm. The hydrogen is used in excess. The implementation occurs at molar ratios of aluminum to organoaluminum compound of 0.1: 1 to 10: 1 instead of. Preferably, with a molar ratio of aluminum to the organoaluminum compound worked from 1: 1 to 4: 1.

The invention is illustrated in the following examples:

B e i s ρ i e 1 1

In this experiment, the equipment consisted of a standard 1-1 autoclave with a stirrer was provided, which rotated at 640 rpm. A test stamp made of stainless steel was placed on the shaft of the stirrer Steel applied to cylindrical specimens with a diameter of 0.94 cm and to hold a length of 2.5 cm. When the experiment was carried out, the end of the cylinder Metallographically polished to allow a delicate examination of the surface topography after the attack of aluminum trialkyl hydrogen solutions. The polished cylinder was on the Brought punch holder, put 150 g of triisobutylaluminum in the autoclave and the autoclave with it Hydrogen up to a pressure of 135 atm at 211 ° C filled. The experiment was carried out for 3 hours. A standard piece of alloy with 12.0 parts each Million zircon in 99.99% aluminum was used as a control sample in the run.

Analysis of the reaction product indicated that 35.2% of the aluminum triisobutyl in diisobutyl aluminum hydride had been converted.

Example 2

Following the procedure of Example 1, 150 g of trioctyl aluminum and 14.8 g of aluminum alloy in Powder form with a content of 2.0 parts per million zirconium converted into 99.99% aluminum. the Analysis of the reaction product indicated that 18.8% of the aluminum trioctyl in dioctyl aluminum hydride had been converted.

Example 3 (comparative example)

Following the procedure of Example 1, 150 g of a mixture of alkyl aluminum compounds, produced by repeated addition of ethylene to aluminum trialkyls of approximately the following composition:

Carbon content of the alkyl radicals Weight percent C ₂ 0.59 C ₄ 3.52 C ₆ 10.57 C ₈ 17.17 C ₁₀ 20.35 C ₁₂ 18.30 C ₁₄ 13.44 C ₁₆ 8.27 C ₁ 8 4.40 C ₂ O 2.06 C ₂₂ 0.85 C ₂₄ 0.32 C ₂₆ 0.10 C ₂ 8 0.04 C30 0.01 99.97

and 12 g 99.99 ° / oig ^it implemented pure aluminum powder. Analysis of the reaction product showed that 9.2% of the "growth product" had been converted to dialkyl aluminum hydride.

Example 4

Following the procedure of Examples 1 and 3, 150 g of the growth product and 12 g of an aluminum alloy were obtained in powder form with a content of 2.0 parts per million zircon in 99.99% aluminum implemented. Ahiminium analysis of the reaction product showed that 27.2% of the "growth product" was converted to dialkyl aluminum hydride ίο had been.

Claims (1)

Claim: Process for the preparation of dialkylaluminum hydrides with alkyl radicals with more than 2 to ¹ S 40 carbon atoms by reacting aluminum trialkyls with identical or different alkyl radicals with the exception of aluminum triethyl at elevated temperatures and pressures with hydrogen in the presence of aluminum, thereby so marked; that instead of Aluminum uses an aluminum alloy that contains about 0.02 to 2 percent by weight of titanium, vanadium, Contains zirconium, niobium, scandium, uranium or hafnium. 409 727/474 11.64 @ Bundesdruckerei BerHn