SU132136A1 - The method of electrolytic production of alkyl derivatives of metals of groups II-V of the periodic system - Google Patents

Description

A known method of producing metal metals, the essence of which is that the complex organoaluminum compounds are electrolyzed with an applied anode of the metal whose compounds must be obtained.

However, in the electrolytic production of metal alkyls by this method, the reverse decomposition of metal alkyl metals formed on the anode under the action of a metal released on the cathode takes place, and there is also the difficulty of separating the anode electrolysis products, I. c. mixtures of the resulting metal alkyls with aluminum trialkyls formed at the anode as decomposition products of the electrolyte.

The described method for the electrolytic production of alkyl compounds of metals of the II-V groups of the periodic system of elements is devoid of the listed drawbacks, due to which it becomes possible to obtain these compounds technically and economically.

The method consists in that the electrolyte containing compounds with the general formula MeiAlRaRT (where R is an alkyl radical; R is alkyl, alkoxy, aroxyl or substituted aroxyl or a fluorine atom; Me is sodium, potassium, or a mixture of sodium and potassium), is electrolyzed with the use of anodes from the metal whose alkyl derivatives must be obtained under conditions that exclude the possibility of reactions between the alkali metal released at the cathode, metal alkyles; and compounds.

No. 132136-2 () 6 may be osuscetil (M {c pa3.iii4iibix variants, of which preference will be given to the variant involving the use of a mercury cathode. Mixing organometallic compounds formed at the anode with sodium discharged at the cathode (the cathode should not form any alloys with alkali metals), it is possible to preserve the separation of the anode space from the cathode space using a diaphragm.

If electrolysis is carried out with a diaphragm without the use of a mercury cathode, then the same organo-aluminum compounds of the above general formula MeiAlRsR in which Me and R have the previously mentioned values are suitable as electrolytes, and R is alkyl alkoxy and, in known cases, substituted aroxyl.

Alternatively, which is particularly suitable for the preparation of volatile metal-alkyl compounds, the electrolysis is carried out in vacuum (residual pressure is less than 1 mm Hg. Art.). Moreover, all metal alkyl compounds that are not bound in the form of complexes immediately after the formation on the anode are distilled off from the electrolyte, thereby eliminating the reaction between the alkali metal and the metal alkyl.

In an embodiment of the method using liquid extracting substances (not immiscible with electrolyte), the electrolyte is constantly washed during the electrolysis with an extracting agent, which also attracts stallerchicoland compounds formed on the anode, and thus prevents them from undesirable reaction with the sodium evolving the cathode. The extraction liquid containing dissolved non-complexed organometallic compounds is withdrawn periodically or continuously from the electrolyzer to isolate the metal alkyl. Saturated hydrocarbons, in particular aliphatic or hydroaromatic hydrocarbons, are particularly suitable as extractants.

All of these options can be implemented individually or in combination with each other.

When using a mercury electrode, in addition to electrolytes with the general formula Me AlR3R, electrolytes can also be used, which additionally contain compounds with the general formula where R is alkyl and R is alkyl, alkoxy or aroxyl. In the case when R is an alkyl radical, i.e., when free aluminum trialkyls are additionally contained in the electrolyte, they can be included in the electrolyte composition also in the form of ethers or complexes with trialkylamines. Preferably, in compounds with the above general formulas, the radicals R are the same alkyl radicals. If R is also an alkyl radical, then it should also be preferred that R and R also be the same alkyl radicals.

Most suitable are those electrolytes in which R is a straight chain primary alkyl radical containing from 2 to 6 carbon atoms; R is a primary straight chain alkyl radical containing from 2 to 6 carbon atoms, or a radical of the general formula OR, where R is alkyl. a radical with the number of carbon atoms from 2 to 20 (preferably from 2 to 8 atoms), a cycloalkyl radical, a substituted phenyl or a fluorine atom; and Me-sodium or a mixture of sodium and potassium, containing in particular up to 80% potassium.

 Among the compounds of the indicated general formulas, preference is given to the quality of the initial electrolytes of the complex compounds with the general formula MdAIR; MefAlRsOR; NaF AiRs; NaF-2AlR3 or mixtures thereof; in addition, there may be other aluminum-isoanic electrolytes.

compounds, for example, non-complexed compounds with the formula and (or) their ethers or complexes with trlalkylamines.

The variant of the work on the proposed method with a mercury cathode, also the design of the electrolyzers required for it, is the simplest. When electrolytes of the above type are decomposed, sodium is first released at the cathode, which is immediately bound by the mercury of the cathode to form amalgama.

The sodium amalgam does not interact with aluminum organic compounds in electrolyte and does not enter into an exchange decomposition reaction with the metal alkyls formed at the anode if the sodium concentration in the amalgam does not reach too high values. In the process conditions, the sodium is removed from the sphere of the reaction, so that special precautions become unnecessary to prevent the mixing of the anodic and cathodic electrolysis products. The electrolysis of the proposed method can be carried out at high current densities without fear of a local increase in sodium concentration in the surface layers of the amalgam and associated with these. Decomposition of organoaluminum compounds contained in the electrolyte.

Even with thin, predominantly applied in practice, mercury layers, when the risk of such an undesirable increase in sodium concentration is especially great, no interference occurs.

The method is suitable for the preparation of alkyl compounds of metals of the II-V groups of the periodic system, since these metals are generally capable of forming electrolytic alkyl compounds.

For the anode, the most common approach are the following, and other metals: beryllium, magnesium, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, tin, lead, mouse, antimony, and bismuth.

The method is suitable for operation in both low and high current densities in the range from 2 to 100 a / dm.

The method can be used at relatively high electrolyte temperatures. Even at temperatures up to 180 ° C, sodium amalgam forming on the cathode is resistant to the electrolyte. Particular preference is given to temperature ranges from 100 ° to 160 °. Electrolysis can be carried out at temperatures below 100 ° if the electrolyte is in a liquid state under these conditions; if necessary, this can be achieved by adding a small amount of some solvents, in particular ethers and tertiary amines or ethers of aluminum trialkyls or their complexes with trialkylamines.

The process is carried out in such a way that the ammalgam formed on the cathode contains no more than 1.5% sodium, for which the cathode metal is periodically or continuously removed and replaced with mercury that does not contain sodium or is poorer in sodium. The permissible limit of sodium content in the amalgam can be the higher, the higher the temperature, of which electrolysis is carried out.

 The amalgam removed from the cell is freed from sodium (at least partially) and then reintroduced into the process. Such regeneration of mercury can be carried out in various ways. For example, sodium amalgam can be electrolyzed using sodium hydroxide, sodium iodide or sodium bromide as the inorganic electrolyte. In this case, metallic sodium is released at the cathode and mercury at the anode.

It is advisable to conduct a process with an electrolyte containing compounds with the general formula MetAlRsRJ, where Me is sodium or a mixture of sodium and potassium, R is alkyl radicals and R is hydrogen, alkyl, alkoxy or aroxyl. At the same time, the radical released at the anode reacts with metallic sodium contained in the amalgam, oOpiKiyn,

- 3 -LE 132136

No. 132136-4-for example, iatriethnol, which immediately reacts with the free trialkylaluminium or alkoxy or aluminum aluminum dialkyl formed at the same time to form the corresponding complex compound, so that the electrolyte composition does not change. Care should be taken that the amalgam "atri" is not too impoverished with sodium both from the surface and as a whole, since otherwise undesirable mercury compounds are formed along with sodium alkyl on the andde. Therefore, only partial extraction of sodium from amalga.chy is preferred. In the case of reuse of mercury treated in secondary electrolysis in a circulation process with successively installed electrolyzers, it can easily be done so that in the first flock, 1) the flow enters the same amount of sodium as it is removed in the second stage is so that , a certain constant amount of sodium remained invariably in mercury.

Preferably, the secondary electrolysis is carried out in such a way that the work takes place in a three-layer method. In this case, the sodium amalgam forms the lower layer on which the molten electrolyte rests. In the latter, several millimeters above the surface of the amalgam, a grid with large cells of insulating material, such as fiberglass or tissue paper, is placed. Sodium excreted in liquid form at the cathode (at 160 °) has a slightly larger specific gravity than the electrolyte, however, the net of insulating material retains it and thus a third floating layer of metallic sodium is formed above the electrolyte. From here, it can easily be removed periodically or continuously.

When it is necessary to obtain particularly pure sodium, such electrolysis can be carried out twice in the same electrolyzer. A second grid of insulating material with a layer of sodium lying on it is placed between the cathode and the anode. The space above this middle layer, M., is filled with electrolyte, so that when current passes through, the sodium is first released from the amalgam in the middle layer as a raw product, and then pure sodium is released in the upper layer.

During electrolysis, metal alkyl compounds are formed from the metal of the anode and the decomposition products of an electrolyte containing aluminum. Subsequent separation of the resulting reaction mixture can be difficult, especially when the boiling points of the formed metal alkyl and decomposition products of an electrolyte containing aluminum are so close that separation by distillation is impossible or difficult.

In order to facilitate the separation, the products formed on the anode, consisting of a mixture of metal alkyl with free aluminum trialkyl, are introduced into the reaction of exchange decomposition with complex compounds of the general formula MeCAlRsOR. This process can be carried out both during electrolysis and after electrolysis outside the electrolyzer. Due to this, the free aluminum trialkyl is converted, as will be described below, into an aluminum metal tetraalkyl and at the same time a free alkoxy or aroxy aluminum dialkyl is formed. From these compounds it is easy to separate the metallky by distillation

The use of this option is most appropriate in the preparation of lead tetraalkyls and, in particular, tetraethyl lead. In other cases, such additional measures may be unnecessary.

At the anode, as a result of side reactions, gaseous products are formed in a small amount, decomposition of hydrocarbon

t; jVti aj HiJ «.MWi-.

kalov. Such unwanted decomposition does not occur at very low current densities, but increases with increasing current density.

At the start of the process in a vacuum-m electrolyzer, it was found that if the current density was increased to the values that were optimal, the formation of undesirable gaseous reaction products again decreased.

The electrolyte decomposition products containing aluminum formed during the electrolysis, it is advisable to turn again such compounds that would be used as electrolyte. Thus, for example, free trialkyl aluminum is again transformed into a complex tetraalkyl compound of an alkali metal and aluminum mixture as a result of treatment with alkaline metals, hydrogen and olefins.

Free alkoxy or aroxyaluminum dialkyl solenenenms can also be converted into complex sodium alkoxyaluminium trialkyl compounds, which can be used as electrolyte or its components to eliminate the undesirable formation of free aluminum trialkyl. Methods for the regeneration of such complex aluminum compounds from the decomposition products of an electrolyte containing aluminum are described below.

The proposed method allows an all-round process of electrolytic production of metal alkyls, electrolyzing compounds with the general formula Me A1H3K, on the anode of that metal, the alkyl compounds of which are to be obtained, and on the mercury cathode. The sodium amalgam formed on the cathode is continuously withdrawn from the cell, freed of sodium from the second cell (at least partially) and fed back to the first cell. At the same time, the formed alkyl chains and electrolyte decomposition products containing aluminum are removed from the cell and separated from each other. The decomposition products containing aluminum, together with the sodium obtained from the secondary electrolysis from sodium amalgam, are then converted by treatment with hydrogen and olefins into the starting compounds MelAlRsRJ, which are again used for electrolysis. In this embodiment of the process, the production of metal alkyls requires (without taking into account the loss of organo-aluminum compounds), the metal whose alkyl compounds are to be obtained, hydrogen and the corresponding olefins. All other substances are in circulation.

Electrolysis can be carried out at relatively low voltages at the terminals of about 1-5 in.

The choice of the design of the electrolyzer and its mode of operation depends on the properties of the resulting metal alkyl and the electrolyte used. The simplest case is the production of aluminum triethyl or magnesium di-ethyl. Metallically formed, while not mixing with the complex electrolyte, rise up and can be removed from the electrolyzer.

In other cases, for example, when producing tetraalkyl lead, the resulting metal alkyl is lowered. If no special measures are taken, then the surface of the mercury cathode is quickly covered with a layer of metal alkyl, as a result of which the current passes through the electrolyte. In order to avoid this, a mobile electrolyte is used, which, leaking over the surface of mercury, carries with it the descending droplets of metal-alkyl, which are then collected in a special sedimentation part of the apparatus.

In the preparation of volatile metal alkyl compounds, the particular difficulty lies in the separation of the mixture which is formed on the anode of the ionomer-5-L 132136

No. 132136- 6 of plexus alkyl compounds of the anode metal with electrolyte decomposition products containing aluminum.

This difficulty is alleviated by using complex compounds with the general formula AkIAlRsOR as the electrolyte. In the case of producing tetraethylsilica, Me means sodium, which may be partially replaced by potassium, R-alkyl with a straight chain having, in particular, 2 carbon atoms, and a. Alkyl, n-Meyun, in particular, from 2 to 8 carbon atoms, or in certain cases, the substituted aryl radical. The OR radical may therefore be a radical of an aliphatic primary or secondary alcohol, or cycloaliphatic alcohol, for example cyclohexanol. Aroxradicals can also be used, but alkoxy radicals should be preferred. In this case, electrolysis at the cathode produces liquid sodium, and at the anode a mixture of tetraethyl lead and 4 molecules of the AlRoOR compound.

Compounds with the general formula AiR2OR are not as reactive as aluminum trialkyls. They are more stable with respect to tetraethyl lead, have a higher boiling point than the corresponding aluminium trialkyls, and therefore can be easily separated from the resulting metal alkyl. The electrical conductivity of the complex compounds of MefAlRaOR is relatively small, so the electrolysis of such compounds requires a significant power consumption.

However, the mere possibility of easy separation of tetraethyl lead justifies the increased power consumption.

Electricity consumption can be significantly reduced by using a mixture of complex compounds MeLAlRsOR and complex compounds of the general formula MefAlR l as an electrolyte, since the conductivity of the latter must be at least 10 times higher.

The use of MeJAlR as electrolyte, where Me is sodium, allows the electrolysis to be carried out so that the metal is liberated at the cathode in liquid form.

When using the corresponding potassium compounds, there are difficulties in the release of metal at the cathode. However, potassium compounds are more efficiently conductive than sodium compounds, so it is advisable to use electrolytes consisting of potassium aluminum tetraalkyl and sodium alkoxy or sodium alumina trialkyl or even three components:

, and MefAlRsOR.

It is important that lead tetraethyl or the other metal alkyl obtained is separated as easily as possible from the alkoxy or aroxyaluminum dialkyl formed with it. By appropriate selection of the OR residue, one can move apart the boiling points of both components. However, HE should not be too small, since then its boiling point would be too low; but it should not be chosen and too large, since otherwise "the ballast, because OR is an inert part of the electrolyte, is too large, and the electrical conductivity of the complex electrolyte drops.

For the preparation of tetraethyl lead, for example, recommended butoxydiethyl aluminum. A mixture of 1 mol of Pb (C2H5) 4 and 4 moles of (C2H5) 2 AHC4H9 consists by weight of / s (rounded) tetraethyl lead and / 3 butox. Diethyl aluminum. Simple, single distillation allows to obtain tetraethyl lead in the form of distillate and lead-free aluminum compound in the residue. In this case, the main constituent of the electrolyte is compound (C2H5) ZOCNH9, but other similar compounds can be used. The advantage of these compounds is that their CMCCII, for example, with lead tetraalkyls are less likely to decompose when heated.

MelAlR OR compounds used as electrolytes can be obtained:

a) the interaction of complex compounds with alcohols or phenols by the reaction:

MefAIR4l + HOR Me AlR30R ± HR;

b) the interaction of aluminum trialkyls with sodium or potassium alkoxides or with their phenols by the reaction:

AlR3-fMeOR Me AlR3OR;

c) by careful oxidation of aluminum trialkyls with oxygen, taken at the rate of 2 mol per 1 mol of the organoaluminum compound, only compounds in which R R can be obtained. The reaction follows the equation:

d) interaction of the compound R2A1OR formed during electrolysis at the anode with aluminum trialkyl and sodium or potassium according to the following equation:

3R, AlR3 + A.

The resulting al / omnium can be reused to produce aluminum trialkyl;

e) addition of an alkali metal hydride to a R2A1OR compound which forms a nanosecond anode, followed by treatment of an adduct with ethylene or another olefin C) H2n-f HC2; and (for ethylene) the following reaction occurs:

MeH + (C2H5) 2AlOR-bC2H4-Me (C2H5bA10R.

This method of obtaining or regenerating electrolyte is the best. The spent electrolyte: or catholyte, in the case when work is performed with a diaphragm, is transferred to a reactor designed for operation, under pressure, sodium and (C2H5) 2A1OR (obtained from the anode space) are also loaded there, conversion of sodium to hydride, and ethylene. The amount of alkali metal released on the cathode during electrolysis is sufficient to regenerate the electrolyte by this method.

Treatment with ethylene is carried out at a temperature of from 130 ° to 220 °, most effectively in the range from 150 to 200 ° and at pressures up to 100 atm, usually in the range from I to 20 atm.

Thus, it is possible to create a circular process for the preparation of a metal alkyl, for example tetraethyl lead, consisting of the following steps:

(C2H5) ЗOR + V4Pb + electropower Me + Al (C2H5) 20R + / 4Pb (C2H5) 4;

Al (C2H5) 20R + MeH + C2H4 Me Al (C2H5) 3OR. This process is reduced to the electrolysis of an alkali metal ethyl compound dissolved in Al (C2H5) 2OR compound using a lead anode.

Potassium aluminum tetraalkyl, which is the main constituent part of some electrolytes, is obtained by the exchange reaction between sodium aluminum tetraalkyl and potassium chloride by the reaction of Na.A. NaCI-H AIR4.

For this, the molten sodium compound is mixed with powdered potassium chloride at 120 ° and the liquid is drained from its insoluble sodium chloride. When potassium chloride is used in an amount of less than 1 mole per mole of sodium compound, it is possible to.

R 3AH- / 202 R 2A10R;

.Me- - / 2H2 MeH;

No. 132136-8 -beam electrolyte with any ratio between sodium and potassium complexes.

Even with a high potassium content in the electrolyte, only sodium is released at the cathode.

The electrolysis conditions are chosen so that liquid metallic sodium is released at the cathode. This can be achieved by maintaining the temperature at the cathode not lower than 100 °, since the sodium melts at 96 °.

Isolation of metallic sodium from an electrolyte containing sodium and potassium is possible only if the content of potassium compound in the electrolyte does not exceed 80%. Sodium electrolyte loss is compensated by the addition of sodium complex compounds. When using a cathode made of copper or iron, liquid sodium released on the cathode in the form of a thin film flows down the electrode. The liquid metal layer formed at the bottom of the cell can be easily deflated.

It is preferable to work with anolyte and catholyte of the same composition. For this, the electrolyte is pre-saturated with R2A1OR, so that during electrolysis, the first small amounts of the resulting metal alkyl and R2A1OR compounds are released as a separate liquid layer.

The following electrolyte compositions are recommended: a) In mole x:

(C2H5) 4l + Na Al (C2H5), (C2H5) (C2H5) (C2H5) 3OR, (C2H5) (C2H5) 30Ra

c) In molar percentages:

Sodium from 100 to 20%; potassium from O to 80% of the total alkali metal content; Mel (C2H5) 4A1, from 95 to 50%; Me (C2H5) 3AlOR -from 5 to 50%.

This method is particularly advantageous when the addition of an alkoxy compound to an electrolyte is not made from the very beginning of the process, but during electrolysis, so that by the time of the beginning of the actual production of tetraethyl lead, the electrolyte consists almost entirely of MeiAl (C2H5) 4l and contains (C2H5) 3AIOR lisch in quantities that are just sufficient to pass the desired reaction; metabolism and correspond to the consumption of alkoxy compounds during electrolysis. With this method, work takes a long time with the greatest conductivity.

In order to separate the resulting metal alkyl from the electrolyte, it is usually used that the anolyte is divided into two layers during electrolysis, one of which contains a significant part of the metal alkyl obtained, along with the compound () 2A1OR. It is also possible to isolate metal alkyl from aiolite by distillation (preferably under vacuum). This, in particular, has to be done when the separation of the layers does not occur at all, that the set takes place when the electrolyte contains a high concentration of complex compounds.

(C2H5) 30R.

Instead of adding a complex alkoxy or aroxy compound to the electrolyte during electrolysis, it is possible to carry out a process by using an electrolyte consisting only of a mixture of aluminum alkyls with a metal alkyl formed at the anode, is withdrawn from the electrolytic cell and treated outside of it with Me / lR3OR complex compounds .

Both described techniques for performing the method provide a liquid alkali metal at the cathode. In the same way, aluminum alkyd or magnonalkyl compounds can be obtained using non-sodium doped cathodes. In the preparation of these metal alkyl compounds, an exchange reaction with complex alkoxy or aroxo compounds is not required, since the magnesium dialkyls are non-volatile compounds, as a result of which no additional measures are necessary and they are necessary for their separation.

An example of a process of this type is the electrolytic method of producing dialkylmagnesium and trialka / talyumini, in accordance with which a complex compound with an obi1 is subjected to electrolysis with the formula (where Li is sodium or a mixture of sodium and potassium, R is alkyl radicals containing, in particular, from 2 to 6 carbon atoms). The anode, in this case, is made, respectively, from magnesium or aluminum.

The material for the cathode can be all electrically conducting materials that, under the reaction conditions, do not fuse with the sodium liberated at the cathode.

During electrolysis at the anode, metal alkyl is formed from the metal of an iodine and an alkyl radical and free aluminum trialkyl as a product of electrolyte decomposition. Undesirable complications in the release of sodium at the cathode and the metal alkyl at the anode are eliminated by using a diaphragm to separate the cathode space from the anode one.

Upon receipt of the aluminum trialkyl, the process of electrolysis is better carried out under vacuum. At the same time, aluminum trialkyl formed on the anode is distilled from the electrolyte immediately after its formation. Another possibility is to use liquid extractants that are not displaced with the electrolyte and remove the organometallic compounds formed on the anode. In this case, the electrolyte is constantly washed during the electrolysis with the extractant.

When working with an aluminum anode, only trialkyl aluminum is formed, and for each equivalent of aluminum trialkyl produced by dissolving the anode, three equivalents are simultaneously obtained due to decomposition of the electrolyte, and a total of four equivalents of aluminum trialkyl are obtained.

To carry out a circular process for the preparation of a trialkylaluminium, a complex compound of the type Me is subjected to electrolysis. The trialkylaluminum formed at the anode is separated from the electrolyte. (4), this amount of trialkylaluminum, together with the sodium liberated at the cathode, is treated with hydrogen and a corresponding olefin outside the electrolyzer to convert them again into a complex compound, which is then periodically or continuously introduced into the electrolyzer. In such an embodiment of the method, the raw materials that are p3 consumed to produce aluminum trialkyl are: aluminum, hydrogen and olefin. Other materials used in electrolysis are in circulation (they are used only to compensate for losses). Similarly, the circular process for producing dialkyl magnets is carried out.

Example 1. An electrolyzer (Fig. 1) is used to produce tetraethyl, which is a steel cylindrical vessel / with a cap 2, to the lid of which (not shown) massive lead anodes are suspended 3. Mercury is used as a cathode enamelled plate 4, located under the anodes. Mercury: and the spray enters the plate from one side and is discharged from the other. The tetraethyl lead formed during electrolysis is collected in the lower constricted part of the vessel / and is periodically lowered with the help of cranes 5-9 -K 132136

A stirrer b is installed in the center of the electrolyzer, which ensures the circulation of the electrolyte and the entrainment of droplets of tetraethyl lead formed from the space between the cathode and the anode to the lower part of the electrolyzer.

in the apparatus shown in FIG. 1, electrolyte using a lead anode mixed electrolyte consisting of 50% aluminum caps tetraethyl and 50% sodium aluminum tetraethyl at 100 °, 1 current of 60 A / dm and a voltage of 7.5 volts. As the electrolysis progresses, 66 (C2H5) 4 is added to the electrolyzer for every 26.8 Ah. A mixture of 81 g of tetraethyl lead and 114 g formed on the anode is hardly soluble in the electrolyte. aluminum triethyl is assembled in the lower part of the apparatus and from time to time merges from there. Amalgam-forming atomic cathode with a concentration of approximately.% Is continuously withdrawn through a special tap into the second electrolyte; ep, where sodium is taken from the amalgam to residual content, 2%. Sodium depleted amalgam is continuously returned to the first electrolyser.

For every 26.8 ach, 81 g of tetraethyl lead, 114 g of triethyl Luminea (100% of the theoretical) and 23 g of sodium (in amalgam) are obtained.

The separation of tetraethyl lead from aluminum triethyl is carried out by decomposition of the benzene with sodium alkoxy alkyl triethyl and after distillation.

Example 2. The procedure is as described in Example 1, but a mixture of 90% sodium aluminum tetraethyl and 10% atridecyloxyaluminium triethyl is used as the electrolyte. As the electrolysis proceeded, sodium decyloxy aluminum triethyl was given at the rate of 294 g for each 26.8 Ah. A mixture of tetraethylnon and decyloxyaluminium diethyl is isolated in the form of a sparingly soluble layer that collects at the bottom of the vessel, from where it is occasionally lowered through valve 5. From this mixture at 1 mm Hg. Art. with a bath temperature of 100 °, tetraethyl-wine is distilled; ;. The residue from distillation, which is pure decyloxyaluminium diethyl, is treated with sodium hydride and ethylene at 190 ° and 10 ag for conversion to sodium decylo xyalumin triethyl, which is reused. In electrolysis;

When sodium amalgam is at a level of 1.5% sodium, it is continuously withdrawn from the electrolyzer, leaving a quantity of poor amalgam containing 0.2% sodium.

. In the same way, the following compounds were obtained using anodes from the corresponding metals (better in the form of granules);

) During the preparation of diethylmercury, the anode space of the electrolyzer was supplied with gutters of insulating material (Teflon, polyethylene) for receiving liquid | mercury

Example 3. In the apparatus shown in FIG. 1, the electrolyte of the complex compound NaF 2A1 (C2H5) was conducted using an aluminum anode. As the electrolysis progresses from above, molten sodium aluminum tetraethyl is admitted to the electrolyzer in accordance with the amount of electricity consumed. Electrolysis temperature 150 °; current density of 20 Idm at a voltage of 3.5 V clips. The triethylamine formed on the anode, which is poorly soluble in the electrolyte, floats as an upper layer and is withdrawn from the electrolyzer. At 26.8 Ah, 152 g of aluminum triethyl are recovered, of which 38 g are newly formed.

Sodium amalgam is treated as described in Example 1.

Example 4. Electrolysis is carried out with the same electrolyte as in Example 3, but using a lead anode and at 70 °. An electrolysis passage is fed to the electrolyzer for every 26.8 Ah 156 g of sodium aluminum trifluoride and 166 g of sodium aluminum tetraethyl in molten state. The voltage at the terminals is 5 V, the current density is 10 a1 dm. Pure tetraethyl lead is precipitated from the electrolyte and precipitates at the bottom of the electrolyzer, from where it is removed from time to time. At the same time, 26.8 oh 270 g of NaF 2A (C2H5) 3 are continuously withdrawn from the electrolyzer for removal of BoF JHHoro tetraethyl lead, 24 g sodium hydride is added and heated to 100 ° while moving. The sodium hydride is completely dissolved. The resulting mixture of 156 g of (C2H5) 3F and 138 g of (C2H5) sN is treated at 150 ° and 20 atm with ethylene until the pressure drop stops and a mixture of 156 g of NaiAl (C2H5) 3F and 166 g of sodium tetraethyl is obtained, which is again fed to electrolyzer.

- 11 - Lo 13213B

No. 132136- 12 The solvent is distilled off from the octane solution, and the remaining tetraethvinyls are added to the separated solution directly in the electrolyzer.

Just get for every 26.8 ah 79 g of total lead (98% of theoretical).

Sodium amalgam is treated as described in Example 1.

Example 5. Do so as ogGisano in example 1, but using a magnesium anode. At the anode, a compound of composition Me (C2H5) 2 2A1 (C2H5) 3 is formed, which is released as an upper layer, as it is poorly soluble in the electrolyte. When this compound is heated to 100 ° under vacuum of 0.001 mm Hg. Art. triethyl aluminum is distilled off and pure diethyl magnesium is left in the amount of 39 g for every 26.8 Ah (96.5% of the theoretical).

EXAMPLE 6 An electrolyzer is a heated cylindrical vessel with a layer of mercury at the bottom of 1-2 cm. The space above the mercury is filled with molten sodium aluminum tetraethyl. A package of vertical, closely spaced others-zinc plates is immersed into this electrolyte. The plate thickness is 2-3 mm, the distance between them is 2 mm. Such an arrangement of the plates is advisable, since during electrolysis, gas is formed at the anode in small quantities, which can easily be discharged through the gaps between the vertically arranged plates. The distance from the packet to mercury is several millimeters. The electrolysis is carried out at a voltage across terminals 4 V, current density 15 and temperature 125 °. The zinc plates at the lower edges gradually dissolve, mercury goes into sodium amalgam, and the mixture consisting of diethyl zinc and aluminum triethyl is collected on the surface of the electrolyte, which is continuously withdrawn from the cell.

In the course of electrolysis, molten sodium-aluminum tetraethyl is supplied to the electrolyzer at the rate of 166 g for every 26.8 Ah. When the sodium concentration in mercury reaches 1%, the amalgam is removed from the electrolyzer and replaced with amalgam from the secondary electrolysis. Sodium extraction from the amalgam is carried out in another electrolyzer to a residual content of approximately 0.2%, after which the amalgam can be reused as a cathode.

The resulting mixture of diethylzinc and triethylaluminium is distilled under vacuum at a residual pressure of 20 mm Hg. Art. and a temperature of 50 ° (in liquid). Diethyl zinc is distilled off, and the remaining triethyl aluminum is converted by treatment with sodium hydride and ethylene at 20 atm and 180 ° into sodium aluminum tetraethyl, which can be used for new electrolysis.

The output of Zn (C2H5) 2-59 g 26.8 Ah (97% of theoretical).

Example 7. Do as in example 6, using as an anode plate of cadmium. From the resulting mixture of triethylaluminum and diethylcadmium, the latter is distilled off under vacuum at a residual pressure of 20 mm Hg. Art. and at a temperature of 80 ° (in liquid).

The output of Cd (C2H5) 2-82 g 26.8 Ah (95% of theoretical). H

Example 8. Proceed as in example 6, using as an anode plate of antimony. The resulting mixture of triethyl antimony and triethylaluminum is heated under vacuum at a residual pressure of 15 mm Hg. Art. up to 90 ° in liquid). In this case, the triethyl antimony is completely distilled. Minor amounts of triethylaluminum are contained in the distillate. Triethyl antimony can be purified from this impurity by simple distillation with water vapor, since 5L (C2H5) 3 does not react with water.

Output 3H (C2H5) s-70 g per 26.8 Ah (100% of the theoretical).

Example 9. In the electrolyzer (Fig. 2), preferably in the molten state is loaded with sodium aluminum butoxytriethyl. The cathode is a copper cylinder D at a distance of 1 cm from which the perforated cylinder 2 is made of porcelain or plastics, such as polypropylene, high molecular weight low-density polyethylene or fabric-strengthened tank. A diaphragm made of hardened filter paper, made of thin cloth or glass filter cloth, is pulled onto a cylinder. The anode space 3 is filled with lead balls. As lead dissolves during electrolysis

No. 132136-14 -

the lead balls are continuously filled. The heating of the electrolig or the removal of the heat generated by the current is carried out with the help of a liquid with a temperature of about 100 ° circulating inside the cathode. Heat is supplied or removed from the outer cylinder in such a way that the temperature in the anode space is no higher than 70 °. It is advisable to have during the electrolysis temperature in the cathode space of about 100 °, and in the anode one - about 70 °. The current is set to 15 A at a voltage across the terminals of 30 V, which corresponds, for the dimensions indicated above, to the apparatus of anode current density of 4 A / dm and cathode current density of 10 A / dm. The sodium formed on the cathode flows down as a thin film over the cathode surface to the lower part of the cathode space, from where it descends from time to time in molten form. The descent from the anode space is set in such a way that the descendable reaction mixture contains about 10% of tetraethyl lead; it also has a place then, when about 500 cm of liquid descends from the anode space into the hour. The influx into the cathode space should be regulated so that the liquid level in the cathode space is 4-5 cm higher than in the anode space. When distilled under vacuum at a residual pressure of 0.5–0.3 mm Hg. and 40-42 ° (in pairs) first, tetraethyl lead is distilled off, then at 120-150 ° (in liquid) butoxydiethyl aluminum. 2.8 g of tetraethyl lead (yield 93% of the theoretical) and 5.9 g of A1 (C2H5) 2 () are obtained per 1 Ah.

Example. 10. Electrolysis is carried out according to Example 9, using a mixed electrolyte consisting of 5 moles (830 g) (C2H5) 4 and 5 moles (1050 g) (C2H5) 3 (OC4H9).

The conductivity of the electrolyte is 0.01 o.i.cm- at 100 °.

With a voltage across the terminals of 9 volts, the force of the passage of a current of 20 a, which corresponds to an anode current density of 5.3 A / dm and a cathode current density of 13 a1 dm, is obtained. The liquid products formed at the cathode are periodically withdrawn from the electrolyzer, and the runoff from the anode space is set so that the descent of the reaction mixture contains 20% of tetraethyl lead. To regulate the cathode space, set the difference between the levels of the cathode and the anode liquid at 4 cm. For 5 hours, 1880 g of electrolyte is passed through the installation and after stopping (switching off the current) the rest of the electrolyte is released. All liquid is divided into 2 layers, which are separated from each other. The bottom layer is a mixture of tetraethyl lead and diethylbutoxyalkyl aluminum, the top layer is molten sodium aluminum tetraethyl with some sodium aluminum butoxytriethyl content. The bottom layer is distilled under vacuum. Corresponding to a residual pressure of 0.5 mm Hg. at the same time, tetraethyl lead in the amount of 286 g (95% of the theoretical) is first distilled at 40 °. The residue from distillation consists of diethylbutoxyaluminium, which is again converted to the complex sodium aluminum butoxytriethyl. Before removing the regenerate with the rest of the electrolyte, the latter should be again heated to 100-120 ° under vacuum at a residual pressure of 0.5 mm Hg. to completely release it from tetraethyl lead, and only then the regenerated complex salt is added, after which a new electrolysis operation can be started.

Example L1. In this example, an electrolyzer is used, which consists of a strong steel cylinder designed for vacuum, with a copper sheet cathode located in the middle, on either side of which anodes of thick lead plates are located on a distance of 1-2 cm. The anodes are passed through the cylinder head and insulated from it. The cathode has electrical contact with the steel vessel body and reaches its bottom. Between the bottom and the lower end of the anode, a free space of about 20 cm is left. An electrolyte consisting of 80% potassium metal and 20: sodium aluminum tetraethyl is introduced into the electrolyzer under nitrogen atmosphere. The electrolyzer is connected through a descending cooler with a cooling receiver and a vacuum pump, heated to 130-140 ° C and created in non-contraction as low as possible a residual pressure of 0.1 mm Hg. Art. Then molten sodium aluminum ethoxytriethyl is slowly fed and the current is switched on when about 5% oobejMa of the electrolyzer is occupied by this substance. A current strength corresponding to a density of 10–30 A / dm is established and the second electrolyte starts to be supplied continuously at a rate corresponding to the current density, i.e. 6.78 g per 1 ampere hour. During electrolysis, a continuous distillation of the mixture consisting of tetraethyl lead and ethoxydiethyl aluminum in the amount of 3 g of tetraethyl lead and 4.85 g of ethoxydiethyl aluminum per 1 ampere hour occurs. With such a process, the complex electrolyte containing sodium and potassium remains almost unchanged in the electrolyzer, but only the added sodium aluminum ethoxytriethyl decomposes. Molten sodium is collected in the lower part of the electrolyzer in the amount of 0.86 g per 1 Ah. The electrolysis can be continued until the sodium level in the electrolyzer rises so much that it can lead to a short closure with the anode. Sodium is drained in a liquid state after a temporary descent of the vacuum and switching off the current. Distillate was distilled under vacuum in a column into tetraethyl lead (boiling point 38 ° / 1 mm) and ethoxydiethyl aluminum (boiling point 72 ° / 1 mm). The sodium obtained by electrolysis is converted by a known method into sodium hydride and then used to regenerate the electrolyte.

Example 12. In the anodic space of the electrolyzer described in example 9 and filled with molten sodium pyrylumine tetraethyl, sodium docyloxy alumina triethyl (or sodium isohexyloxynumine triethyl) is continuously fed from the top at a rate corresponding to the passage of current. The current is switched on simultaneously with the start of the supply. In passing through current, 11 g of sodium decyloxy aluminyl triethyl (respectively, 8.9 g of sodium isohexyloxy aluminum) 1 are served hourly. At the bottom of the anode space, a liquid layer of a mixture of decyl sialuminium diethyl (respectively izhexyloxy aluminum diethyl) and tetraethyl lead containing 25 weight percent tetra ethyl lead is collected. This layer is continuously removed in such a way that the main electrolyte — molten sodium, titanium tetraethyl — remains unchanged in the anode space. In the cathode space, the electrolyte level should be approximately 4 cm higher than in the anode one. It is advisable to supply both cathodic and anodic spaces with overflows and to continuously introduce sodium aluminum tetraethyl into each, preferably in molten form, with such a speed that it will overflow a little, and the overflow electrolyte will flow back into the sodium aluminum tetraethyl tank.

A certain amount of sodium aluminum tetraethyl is also poured from the anode space, moreover, the more the lumenche the diaphragm passes. This part of the sodium aluminum tetraethyl cannot be returned directly to the tank, since the lead tetraethyl is contained in the nem; to free it, sodium aluminum tetraethyl is heated to 100 ° under vacuum.

The electrolyzer can operate at a current of 10-30 a, i.e. it is possible to enter into the reaction hourly 110: 330 g sodium decyloxy aluminum tri-15 -L 132136

Lg 132136-16 ztila (respectively, 89-267 g of sodium nitrohexnloxane aluminum triethyl) to obtain 120-360 g of a mixture of tetraethyl lead and decyloxyaluminium diethyl (respectively, 100-300 g of a mixture of tetraethyl lead and ethylenediamine), from which you can use the unit to go to the unit to go to the unit to get the unit, but did not go to the unit to get the unit, but did not go to the unit to get the unit, but did not go to the unit to get the unit, but did not use the device to get the unit to get the unit, but to go out of the unit to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to get the 4, but it was used to put the 4 tetraethyl lead.

To convert decyloxydiethylaluminium into complex sodium aluminum decyloxytriethyl (respectively isohexyloxydiethylaluminium into complex sodium aluminum isohexyloxytriethyl) they are treated with sodium hydride and ethylene.

During long-term electrolysis, it is desirable to conduct the process so that there is some excess of complex oxysilane in the electrolyzer, since otherwise triethylaluminum is released on the anode, which can cause a disruption in the normal course of the process. To avoid this, it is possible to add about 5% of the complex oxo compounds to the initial electrolyte in advance. If in the future, due to the too rapid supply of the complex oxo compound, its content in the anode space increases (which becomes noticeable due to a decrease in electrical conductivity), then the influx of the complex oxo compound temporarily decreases.

Example 13. Electrolysis is carried out according to Example 9, using sodium aluminum phenoxytriethyl and sodium aluminum tetraethyl as electrolyte. With a voltage across the terminals of 10, the current is 20 a. The removal of electrolysis products from the anode space is adjusted so that the mixture is lowered to contain 20% tetraethyl lead. Adjusting the flow of electrolyte into the cathode space establish the level difference in the cathode and anode space in 5 cm.

Within 10 hours, about 3000 g of electrolyte is passed through the unit. The mixture of liquid products that is withdrawn from the electrolysis cell is stratified into two layers, which are separated from each other. Tetra ethyl lead is distilled from both layers at a pressure of 0.5 mm. Hg Art. and a temperature of 120 ° (in liquid). Get 570 g of tetraethyl lead (95% of theoretical amount). The residue from the distillation of the lower layer is phenoxydiethyl aluminum, the residue from the distillation of the upper layer is sodium aluminium tetraethyl.

Example 14. A mixture of equimolar amounts of sodium alumina hexaoxytripropyl and sodium alumina tetrapropyl is subjected to electrolysis according to example 9.

With a current of 10 a, the removal of electrolysis products from the anode pro; 1mstva is regulated so that the descentable mixture contains uC

;: ropilsvintsa For 5 hours through the electrolyzer pass about

,:: electrolyte. The distillation of tetrapropyl lead from the mixture is carried out at

100 ° (when measured in a liquid (spine) and a pressure of 0.1 mm Hg. Art.

The yield of tetrapropyl lead-160 g (90% of theoretical).

Example 15. A mixture of equimolar amounts of sodium aluminum tetrabutyl and sodium aluminum decicycloxytributyl is subjected to electrolysis as indicated in Example 9. From the resulting mixture containing 10% tetrabutyl lead, the latter is distilled under vacuum, corresponding to a residual pressure of 0.001 mm Hg. Art. and 120 ° (in liquid). Output - 80% of theoretical.

Example 16. An equimolar mixture of (C5Hii) 4J and (C5HiB (OSbN5) is subjected to electrolysis at 100 ° in the electrolyzer described in example 1 using a zinc anode. At a current of 10 a and a mixture containing 10% Zn from the anode space (C5Hii) 2 electrolysis is completed after 5 hours. The electrolyte is heated under vacuum (at a pressure of 1 mm Hg) to 70-80 °, while the resulting Zn (CsHn) 2 is distilled off. The yield is 171 g (90% of theoretical ).

With further heating under high vacuum (0.0001 mmHg) at 130-140 °, 480 g (1.84 mol) of A1 (C5Hp) 2 (OSbH5) are distilled off. The distillate is charged into a nitrogen-purged autoclave, together with 44 g of sodium hydride and 250 ml of pentene, and heated to 150 ° for 7 hours while swirling or boiling. Excess pentene is distilled off and the resulting complex compound Nal.Ml.CsHiOaCOCeHo) is combined with the residue from distillation and used for the next electrolysis.

Example 17. 3320 g (20 moles) of sodium aluminum tetraethyl are mixed with 740 g (10 moles) of potassium chloride for 5 hours at 150 °. After precipitating the resulting sodium chloride, the resulting equimolar mixture of sodium aluminum tetraethyl and potassium aluminum tetraethyl is subjected to decomposition in a lead anode and copper cathode electrolyzer in the form of cylinders, between which a perforated cylinder of non-electrically conductive material is formed by the body and a body of body is removed. bakelite, hardened with a cloth, etc.). The diaphragm is attached to the cylinder from reinforced filter paper or from thin filter cloth or glass cloth. The anode space is filled with lead balls, filled as they dissolve.

The heating of the electrolyte or the removal of heat released during electrolysis is produced by means of a heated to 100 ° liquid circulating through the channels inside the cathode. During electrolysis, the temperature in the cathode space is maintained at approximately 100 °, and in the anode space, around 70 °. The electrical conductivity of the mixture used is 4.5 10 ohm-cm at 100 °. Amperage of 20 a with H; I bp 2 b.

The selection of electrolysis products from the anode space is regulated so that in the exhaust reaction mixture contains about 20% of tetraethyl lead. Within 12 hours through the electrolyzer passes at 20. g about 3600 g of electrolyte. The electrolyte released from the anode space consists of two layers. The top layer, containing mostly sodium aluminum tetraethyl, is released under vacuum at a residual pressure of 0.5 mm Hg. Art. and 120 ° from small amounts of dissolved tetraethyl lead and aluminum triethyl and can be recycled again. The distillate is combined with a lower layer consisting of 700 g of tetraethyl lead and 1020 g of aluminum triethyl. The separation of the mixture is carried out in accordance with the indications given in the following examples.

Example 18. A mixture of 700 s of tetraethyl lead and 1020 g of aluminum triethyl from 1880 g of sodium aluminum butoxytriethyl is transferred for one hour at 100 °. After stopping the stirring, the mixture is divided into two liquid layers. The upper layer is heated under vacuum at a residual pressure of 0.5 mm Hg. Art. and at 100 ° to release small, dissolved tetraethyl lead. The remaining sodium aluminum tetraethyl is recycled. The bottom layer, which is a mixture of tetraethyl lead and butoxydiethyl aluminum, containing about 30% (by weight) of tetraethyl lead, is distilled under vacuum at d.-. ground pressure of 0.5 mm Hg. Art. and at 70-80 ° (in liquid). Pure tetraethyl lead is distilled off under these conditions. The yield of tetraethyl lead with.) Is 695 g (99% of the theoretical).

Instead of sodium aluminum butoxytriethyl, sodium aluminum hexahoxytriethyl, sodium aluminum isooctyloxytranethyl, sodium aluminum decyloxytriethyl, sodium aluminum phenoxytriethyl, etc. can be used.

No. 132136

# 132136- -.18Pcgearization of the combic sodium alkoxy- or aromaticum-aluminum-alkyl compounds can be carried out as follows.

742 g (4.7 mol) of A1 (C2H5) 2 (OC4H9) are heated with 4.7 g of sodium hydride under stirring under an atmosphere of nitrogen or argon at 120–140 ° for half an hour. During this time, the entire sodium hydride is dissolved and the reaction mixture in a liquid state is lowered into a two-liter autoclave, flushed with nitrogen, and injected with ethylene to 50-60 atm. Autoclave or shake at 140-150 ° until pressure change ceases. This is usually observed after 4-5 hours. The autoclave produces pure (C2Hs) 3 (OC4H9). The output is 990g. (100% of theoretical). This compound can again be used to separate tetraethyl lead from an electrolyte consisting of sodium aluminum tetraethyl and potassium aluminum tetraethyl.

Similarly, you can also get tetrapropyl lead and tetra - "- butyl lead. It is necessary to proceed from the corresponding propyl and butyl compounds.

Example 19. Proceed according to example 17, but aluminum pellets are loaded into the anode space. The current is 15 A at a voltage across the terminals of 3 V, which, for given dimensions of the apparatus, corresponds to a current density at the anode of 4 oidM and a density of the current at the cathode of 10. The sodium formed on the cathode flows down as a thin film over the cathode surface to the lower part of the cathode space, from where its time is diverted from time to time in the opened state.

Aluminum triethyl formed at the anode is poorly soluble in the electrolyte and rises to its surface drop by drop, forming a second liquid layer in the anode space, which is removed from time to time. The flux of sodium aluminum tetraethyl in the cathode space should be adjusted so that the level of the liquid in the cathode space is 4- 5 ot higher than in the anode space.

The yield of newly formed aluminum triethyl is 1.4. "A 1 ick (99% of theoretical). In total, 5.7 g A1 (C2H5) h is released in the anode space. This quantity is obtained from the electrolyte and converted back to sodium aluminum tetraethyl by reaction with NaH and ethylene at 180 °.

Example 20. The procedure is as in Example 19, but sodium aluminum tetrapropyl, preferably in the molten state, with a temperature of about 100 ° is fed to the electrolyzer. The current strength is set to 15 A at a voltage across the terminals of 8 V, which corresponds to a current density at the anode of 4 a / s / g2 and a current density at the cathode of 10 ajdM-. The removal of fluid from the anode space is established so that the descent mixture contains about 20% propyl aluminum. The flow of molten sodium / aluminum tetrapropyl into the cathode space is regulated so that the liquid level in the cathode space is 4–5 cm higher than in the anode space.

The separation of the anode products is carried out by distillation in a film evaporator. Tripropyl aluminum is distilled off (at iOO ° and 1 mmHg). The distillation residue is sodium aluminum tetrapropyl. 4, the amount of tripropyl aluminum produced is converted to sodium aluminum tetrapropyl by treatment with sodium hydride and propylene and is again used for electrolysis. At 1 ach, 1.8 g of newly formed tripropylaluminum is obtained (94% of the theoretical).

Example 21. Proceed as described in example 20, but sodium aluminum tetrabutyl is used as the electrolyte and a mixture of 30% aluminum tributyl and sodium is taken from the anode space.