CS238214B1 - Trans-dichloro-tetrakis(tetrahydrofurane)magnesium complex and method of its preparation - Google Patents

Abstract

The invention relates to inorganic chemistry and chemistry of high molecular weight compounds and solves the preparation of one of the components for production Highly Active Low Pressure Catalysts polymerization and copolymerization olefins. The present invention is not described complex compounds of trans-dichlorotetrakis (tetrahydrofuran) magnesium complex of the general formula [UgCC] the preparation of this compound by reaction of bu3 elemental magnesium with allyl chloride, or hydrogen chloride or Grignard reagents with hydrogen chloride generally in tetrahydrofuran environment and the method of isolation compounds by crystallization from rostok. The compounds can be used to synthesize precursors or various organic catalysts Synthesis.

Description

The present invention relates to a chemical compound of the trans-dichlorotetrakis (tetrahydrofuran) magnesium complex of the formula [Mg (C ₄ H ₆ O) ₄ d ₂ ] hitherto not described and processes for its preparation.

Very often various mixtures containing magnesium and titanium compounds together with electron donor compounds such as various organic acid esters, ethers, amines, alcohols and the like are used as components of catalytically active systems for the industrial production of various types of polyolefins by polymerization and copolymerization of 1-olefins or mixtures thereof. . Precursors of highly active catalyst systems with excellent stereospecific performance were obtained using mixtures of magnesium chloride, titanium tetrachloride and tetrahydrofuran in a wide range of component ratios and with various methods of working and treating the reaction mixture. Particularly good results are obtained in the preparation of precursors from a homogeneous phase, i.e. tetrahydrofuran solutions of magnesium chloride and titanium dioxide. The difficulties caused by the low solubility of anhydrous magnesium chloride in tetrahydrofuran can be avoided by using in place of tetrahydrofuran-soluble, but not yet described in the literature, and completely unidentified and uncharacterized solvates of Mgdg.nC ^HgO where n is 1.5 or 2 Pure chemical individual, trans-dichloro-tetrakis (tetrahydrofuran) magnesium complex [MgCO4HgO3] d], which is formed in the Mgdg-tetrahydrofuran system and which is highly soluble in trahydrofuran, has not been used for similar purposes. There was only one case in the literature about the probable existence of a compound of the formula Mgdg · C ^H HO

- 2 _of CH ₉ - CH ₉ ⁰ I '''''CHg ~ ®2 preparation of this compound,

238 214 warned (Zeil W., Winter J .: Tagungsber.Chem.Ges. DDK 1954, p. 77; Chem. Zentralblatt 1962, 9270), but an attempt at its isolation, analysis, physical and chemical characterization and the method of its synthesis has not been described.

The present invention provides the chemical compound trans-dichlorotetrakis (tetrahydrofuran) magnesium complex of the general formula [kg / Cl2HgO] + Clg] 1 structural formula

i) i)

CL-Mg-Cl, where D is

OF \

The object of the present invention is a process which further comprises reacting either elemental magnesium with allyl chloride in tetrahydrofuran according to the equation

Mg + 2 C ₃ H ₅ CL-4 C ₄ H _q O -> [MgtC ^ HgO) ₄ C1 ^ + CGH ^ or magnesium Grignard of formula RMgd wherein R is an aliphatic, cyclic or aromatic substituent having up to 8 carbon atoms , preferably 1-butyl, with dry hydrogen chloride in tetrahydrofuran medium according to the equation

RMgd f HCl + 4 C ₄ H _q O -> [MgCl 2 gO ₄ dg] + RH or elemental magnesium with dry hydrogen chloride also in tetrahydrofuran environment according to the equation Mg + 2 Hd + 4 C ₄ H _q O - [Mg (C ₄ H _g O ₄ d ₂ ] + Hg

In the process according to the invention, the syntheses are carried out with a starting amount of magnesium of 0.1 to 3.5 moles per liter of tetrahydrofuran (or equivalent amount of Grignard reagent), preferably 2 to 3 moles per liter of tetrahydrofuran and stoichiometric.

Or a slightly above-stoichiometric amount (up to 10%) of allyl chloride at temperatures of 0 to 60 ° C, preferably 25 to 30 ° C and atmospheric pressure, with efficient stirring under a protective atmosphere of dry inert gas (nitrogen or argon). After reaction, the product is isolated by crystallization at temperatures up to 28 ° C. Purification of the product may be accomplished by recrystallization from tetrahydrofuran solutions under the same conditions. The yields are between 50 and 90% of theory.

The preparation of the compound is demonstrated by the following examples.

Example 1

A dry flask (500 ml) equipped with a reflux condenser and an inert gas inlet and outlet was charged with 12.2 g (0.5 mol) of magnesium shavings and 250 ml dry tetrahydrofuran. A total of 80.3 g (1.05 ml) of allyl chloride is added to the suspension while stirring. The feed rate of allyl chloride maintains the temperature of the reaction mixture at 28-30 ° C. After mixing, the reaction mixture is kept under stirring at room temperature until the magnesium present is completely dissolved (3-5 hours). The reaction mixture was cooled to 0 ° C under inert conditions and filtered. The precipitated crystals are drained vigorously and washed with about 50 ml of tetrahydrofuran cooled to 0 ° C. The crude product is dissolved in 600 ml of dry tetrahydrofuran at 25 to 28 ° C, cooled to 0 ° C and left to crystallize at this temperature. The precipitated platelet-like white crystals are suctioned off sharply and washed with 50 ml of cold tetrahydrofuran. The product is dried in an inert stream only briefly to a substantially free-flowing consistency. Yield: 73 g (38% of theory). The mother liquors can be obtained after concentration in vacuo at a temperature of not more than 28 ° C

238 214

- 4 longer product fraction of 30 g (15.5% of theory) · The second fraction is slightly contaminated with traces of the by-product of the reaction, 1,5-hexadiene.

Example 2

A solution of 1-butylmagnesium chloride prepared from 12.2 g (0.5 mol) of magnesium shavings and 46.3 g (0.5 mol) of 1-butyl chloride in 200 ml of tetrahydrofuran is filtered through a glass wool filter into a 3-necked flask (500 ml) ml) fitted with an inert gas inlet and outlet and a separating funnel. To the solution, 100 ml of a 5 mol / l solution of hydrogen chloride in tetrahydrofuran (total 0.5 mol of HCl) was added in small portions over 15 minutes with stirring. During the live reaction, the flask is cooled with water and ice. The resulting crystalline mass of the product is then maintained at 0-5 ° C for 3 hours. The product crystals are then sharply aspirated, washed with 100 ml of tetrahydrofuran cooled to 0 ° C and dried in a stream of inert to a free-flowing state. Yield 150 g (78% of theory). For the purpose of the synthesis of catalytic precursors, the purity of the product thus prepared is sufficient. Further purification can be performed by crystallization as described in Example 1.

The same product was obtained in a yield of 65-75% using Grignard reagents of the formula RMgCL where R is ethyl, 1-octyl, cyclohexyl or phenyl.

Example 3

In a 1000 ml three-necked flask equipped with a reflux condenser and inlet and outlet, 500 ml of a solution of hydrogen chloride in dry tetrahydrofuran (concentration 5 mol per liter) is introduced.

5,238,214, and a total of 30.4 g (1.25 mol) of the sea-buckthorn are gradually introduced upstream of the inert. The rate of dosing is governed by the rate of hydrogen evolution.

As the amount of product increases, the mixture becomes thicker, crystals of the product precipitate and the rate of dissolution decreases. In order to maintain the optimum reaction temperature (28-32 ° C), the reaction space must be cooled at the beginning of the reaction and later heated. The reaction is terminated by complete dissolution of the magnesium. The reaction mixture was then cooled to 0-5 ° C and allowed to crystallize. 324 g of crude product are obtained, which is further purified by recrystallization as in Example 1. Concentration of the mother liquors yields an additional 106 g of product, so that the total yield is 430 g (90%) of the product.

Example 4

A suspension of 30.4 g (1.25 mol) of magnesium shavings in a 500 ml dry tetrahydrofuran in a three-necked (1000 ml) flask equipped with a reflux condenser and an inert gas inlet and outlet was charged with a stream of dry hydrogen chloride gas to control the reaction. The temperature of the mixture was maintained at 30 + 2 ° C. The hydrogen chloride feed is terminated after the magnesium has completely dissolved, which takes 4 to 6 hours depending on the size of the shavings. After the reaction, a slight excess of hydrogen chloride is removed both by purging the reaction mixture with inert gas and by adding a small amount (about 0.5 g) of compact magnesium, which is mechanically removed after reaching the neutral reaction. The reaction mixture was cooled and the precipitated crystals were treated in the same manner as described in Example 3. 440 g (92% of theory) of pure product were obtained.

Product characterization and identification

The appearance and stability of the product 238 214 [MgCl2HgO4Clg] are large, platelet-like, colorless, transparent crystals that are unrestrictedly stable in a closed vessel below 28 ° C.

Ventilates very easily in air and absorbs air humidity.

It easily desolvates under vacuum in dependence on temperature to products containing 1.3 or less tetrahydrofuran in the formula unit.

Desolvation also occurs when the complex is introduced into inert solvents such as hexane, paraffin oil, carbon tetrachloride, benzene and the like.

Chemical analysis

The recrystallized product prepared according to the above-described product has a composition corresponding to the formula [Mg (C? H ₈ 0) Cl ₂ J to affirm the results of chemical analysis shown in Table I.

Table I

Chemical analysis [Lig (Ο ^ ΗθΟ) ^ Clg]

Content of elements and tetrahydrofuran in% Mg Cl c ₄ h ₈ ° Calculated 6,337 18,482 75,181 Found 6.35 18.50 75.15

Powder diffractogram of compound

The compound QdgCl2H2O forms white platelet-shaped well-developed crystals. Powder diffractogram of compound using

238 214

0.154178 nm provides the 2Θ diffraction angles and the inter-plane distances d and the relative intensities of the diffraction lines shown in Table XI.

Table XI

Powder Diffractogram Parameters [MgCl 3

Diffraction angle 2 Θ, ⁰ relative intensity indexes planes mezirovinné distance hkl d, nm

10,2 10

11.4 7

16.7 3

18.9 2

20.4 2

20.8 2

22,2 1

22.9 1

23.3 1

23,6 1

24.3 1

25.4 1

26.3 1

27.4 1

28,2 1

29.9 1

31.0. 2

31.4 1

32,1 1

40.4 1

49,3 1

002 0,867 100 ALIGN! 0,776 111 0.531 112 0.470 004 0.434 0.427 113 0.400 200 0.388 201 0.382 104 0.377 0.367 210 0.351 114 0.339 212,203 0.325 105 0.316 213 0.298 006 0.288 0.285 220 0.279 216,304 0.223 218,403 0.185

The powder diffraction pattern [MgCC ^ HgO ^ Cl ^] is almost identical to the diffractogram and consistent with the full crystal structure

8,238,214 by analyzing the homologous compound of pCO 2 O 2 Br (Perucaud M.C., Ducom J., Vallino M .: Compt.Rend. 264. 571, 1967). Thus, both compounds are crystallographically isomorphic and isostructural.

It is most likely that even the molecular structure is identical. The powder diffractogram shows the following crystallographic parameters (Table III).

Table III

Crystallographic parameters plg (Ο ^ ΗθΟ) ^ Clg]

habit platičky system tetragonal spatial group P 4g2 2 (probably) OF 2 a = b 0.782 nm C 1.734 nm density (calculated) 1206.6 kgm ^

Infrared spectra of compound

The infrared spectrum of a solid state or nujol suspension cannot be reliably measured due to the low thermal stability of the compound and its easy desolvation by the action of an inert hydrocarbon (nujol). The spectrum of saturated solutions in tetrahydrofuran in the region of 1400 to 200 cm @ -1 shows the bands shown in Table IV.

Table IV

238 214

Infrared spectrum of a saturated solution of pIgO (HgO) [O] O] in tetrahydrofuran

Wavelet, • m ” ¹ Intensity Assignment 1340 vw CHg-wagging 1292 vw CH ₂ -wagging 1243 vw CH ₂ -wagging 1180 m expanding circle 1040 vs V _a (00C) in C ₄ H ₈ O ... Mg 887 with V _S (COC) in C ₄ H ₈ O ... Mg 672 m CH ₂ -rocking 590 vw deformation of the circle 445 . sh deformation of the circle 408 m VíblgCl) 348 with V (MgO) 310 sh

vw - very weak, m - medium, s - strong, vs - very strong, sh - shoulder

Electric conductivity

The electrical conductivity of the solutions of [MgCl 2 H 3 O 3] d 4] in tetrahydrofuran is very low. In the concentration range of 0.02 to 0.20 mole ” ¹ , the specific conductivity of the solutions is 0.3 to 9.8.10 x” cm ”at 20 ° C, 0.2 to 6.0.1 θ“ ^ β ^-1 on “ ¹ at 30 ° C and

0.1 to 3.9.10 ^ 52. ^-1 cm ^"1 to 40 ° C. These values are indicative of the molecular nature of the compound tetrahydrofuranových roztocícn and indirectly in the solid state.

Claims (5)

Object of the invention 238 214 trans-Dichlorotetrakis (tetrahydrofuran) magnesium complex in Mg [((Ο ΟθΗ) 4Cl2], structural formula Cl, where (i) means CH _rt / _2V CH _? I ch ₂ 2. A process for the preparation of a compound according to claim 1, characterized in that elemental magnesium is reacted with allyl chloride in a tetrahydrofuran environment. 3. A process for the preparation of the compound according to claim 1, characterized in that the magnesium Grignard reagent of the formula RMgCl, wherein R is an aliphatic, cyclic or aromatic substituent of up to 8 carbon atoms, preferably 1-butyl, is reacted with dry hydrogen chloride in tetrahydrofuran. 4. A process for the preparation of a compound as claimed in claim 1, wherein elemental magnesium is reacted with dry hydrogen chloride in tetrahydrofuran. 5. Process according to claims 2,3 and 4, wherein the product is isolated by crystallization from tetrahydrofuranových solution at 28 ° C _e