DE1070384B - Process for the production of high molecular weight boron-carbon compounds - Google Patents

Description

GERMAN

Of the conceivable compounds that contain boron-carbon bonds, the boron alkyls and the Boraryle known for a long time. They are used e.g. B .-. 'As polymerization catalysts and as fuels. A number of methods for obtaining them are also known.

■ Recently there have also been representatives of a second Class of boron-carbon compounds described, namely boron trivinyl and boron tripropenyl, i.e. substances in which the boron atom is linked to unsaturated hydrocarbon radicals. You put them by reacting halogen-boron or alkylboron compounds with sodium vinyl or propenyl. Because of the C = C bond adjacent to your boron atom caused, some of these substances show properties that differ considerably from those of the boron alkyls.

The great interest, which today is technically Experienced easily accessible boron alkyls is based on two characteristic properties: They have as a result of the electron gap at the boron atom, it has a clear radical character, which determines its value as polymerization catalysts; on the other hand, the high heat of combustion is also based on the relatively high boron content. These two characteristic properties of the boron alkyls are naturally the strongest pronounced in compounds with a low carbon content. On the other hand, it takes a mostly undesirable one -, property of boron alkyls, their self-inflammability, with decreasing carbon content.

So there was an obvious desire to obtain substances that had the first properties mentioned have a high boron-carbon ratio, but no longer spontaneously ignitable, so easier are manageable.

The invention relates to a process for the production of a third class of boron-carbon compounds, namely high-molecular boron-carbon compounds, which is characterized in that boron-hydrogen compounds are reacted with carbon compounds which contain at least one carbon-carbon in the molecule -Triple bond or at least two olefinic double bonds or acetylenic and olefinic multiple bonds mixed. It has been found that unsaturated carbon compounds of the type mentioned, acetylene is mentioned as an example below, can be reacted with boron-hydrogen compounds even under mild conditions. The implementation proceeds particularly smoothly with substances that _{contain BH 3} groups, such as borazanes or boroxanes, which the latter z. B. arise in the implementation of boranates in ethers with boron halides or when introducing boron hydrogen in ether.

Procedure _; ;

for the production of high molecular weight ^; _; Boron-carbon compounds ^{7 ]} "^;;

Applicant:

Farbenfabriken Bayer Aktiengesellschaft ,,; Leverkusen-Bayerwerk?; · .: «

Dr. Friedrich Schubert, Dr. Konrad Lang. ; _f
and Dr. Karl Usefulel, Leverkusen,.,. _: , _r
have been named as inventors. ib; ·.)

For example, if one passes 'through' a suspension, of sodium boranate in tetrahydrofuran, one; vigorous stream of acetylene and drips under vigorous If borofluoride diethyl etherate: is stirred in, it is initially replicated

3 Na BH ₄ + 4 BF ₃ ■ · O (C ₀ H ₅ )., +, 4. C ₄ H ₈ .0. - * .. ·.

- ^, 3 NaBF ₄ + 4 C ₄ HgQ-BH ₃ + _: 4 (C ₂ H ₅ ) 2D _r

C ₄ H ₀ O

BH ₃ , Teträmethylenböroxan, ' a ^: loose

Adduct of hydrogen boride to; Tetrahydrofuran./ Acetylene is added to this, with the formation of boron ¹ 'trivinyl. If the reaction mixture is then filtered, an initially clear solution is obtained, which, however, soon becomes cloudy and finally white flakes separate out. After the solvent has evaporated, a solid, wax-like or rubber-like body with a boron content of 11.5 percent by weight remains. The reaction product is thus formed by polymerizing the intermediate boron trivinyl and has the composition [B (C ₂ Hj) ₃ ] is only slowly oxidized when heated in air.

example 1

In a three-necked flask is through a suspension of 3 gram mol of sodium boronate in 2 l of tetrahydrofuran a vigorous stream of acetylene passed. Now one drips with vigorous stirring and with cooling slowly add 4 grams of boron trifmoride ether with ice water. The internal temperature should not be 40 ° C exceed. After the addition of the boron fluoride ether is complete, another half an hour is passed Acetylene, filtered and distilled after a day

909 687/442

Stand the solvent in a vacuum. It remains behind a white, solid, rubbery to waxy body formed in quantitative conversion a boron content of 11.5 percent by weight.

i> ^ 6 '\; · ".J Example 2

In a three-necked flask with gas inlet tube, dropping funnel, stirrer, reflux condenser, one puts in 2 liters of ether, or better. Tetrahydrofuran 3 gramol sodium: triumboranat with 4 gramol boron fluoride etherate with formation of diborane and passes this with the help of an inert gas stream through the reflux condenser into a second flask which is filled with tetrahydrofuran and into which a vigorous stream of acetylene is introduced at the same time. When heated, which is mitigated by external cooling, a high-polymer product is formed very soon, which after completion of the reaction by evaporation of the tetrahydrofuran. is won purely. Its composition again corresponds to the formula [B (C ₂ H _g ) ₃ ] _ _v . The yield is quantitative.

Example, 3

As described in Example 2, diborane is produced in a glass flask and, with the aid of an inert gas stream (argon), is pressed into a second flask, where it is reacted with acetylene in tetrahydrofuran. In a modification of the procedure described in Example 2, the diborane is metered in in excess, so that some hydrogen boride always escapes from the reaction mixture. The reaction takes place again with heating and the formation of an insoluble, high molecular weight compound which can swell in tetrahydrofuran. This is obtained in pure form by heating the tetrahydrofuran in a boiling water bath under 10 Torr. The analysis shows a boron content of 17 percent by weight. There is therefore a copolymer of B (C ₂ Hj) ₃ and B ₂ (C ₂ HJ ₃₎ .

Example 4

_{115 g of N-triethylborazane (C 2} Hg) ₃ N-BH _{3 are placed} in a three-necked flask equipped with a stirrer, inlet tube and descending condenser. At 110 to 115 ^° C., acetylene is introduced, which is absorbed with an increase in temperature. The acetylene is expediently diluted with nitrogen. After 2 hours the clear liquid becomes cloudy and viscous. Triethylamine and the remaining borazane are distilled off in vacuo. The residue is a hard to semi-plastic 5 'mass that liquefies when heated in air. The boron content is 10.1 percent by weight.

Example 5

In a three-necked flask with a stirrer and dropping funnel 35.5 g of N-triethylborazane are kept at 115.degree. 74.5 g of propargyl chloride are obtained within 1 hour dripped in. The temperature rises slightly. The resulting triethylamine is distilled off. A reddish-brown colored, translucent plastic mass remains, which attaches to the Air liquefies when heated. The boron content is 3.4% boron.

Example 6

In a glass autoclave, N-triethylborazane is diluted with the same volume of toluene and 2 atmospheres Acetylene pressed on. Significant absorption only takes place above 100 ° C. Toluene and triethylamine formed are distilled off after releasing the pressure from the autoclave. It remains a yellowish color Residue as in Example 4 back.

Example 7

In tetrahydrofuran, diborane and butadiene are conducted in a volume ratio of diborane to butadiene, for example 2: 3 a. After the reaction has ended, the mixture is refluxed for a further 1 to 2 hours and distilled then the solvent off. A mixture of oily and solid products of various molecular weights is obtained.

Claims (1)

Claim: Process for the production of high molecular weight boron-carbon compounds, characterized in that that boron-hydrogen compounds are reacted with carbon compounds that at least one carbon triple bond or at least two carbon double bonds or contain carbon double and triple bonds mixed.