CS212828B1 - Chromic acid bis (2-butyldiphenylsilyl) ester and its preparation - Google Patents

Abstract

The invention relates to the field of chemistry, especially the chemistry of organometallic compounds. It solves the preparation of one of the components for the production of highly active catalysts for the low-pressure polymerization of 4-olefins, especially ethylene. The invention describes the existence of a previously unknown chemical compound bis (2-butyldiphenylsilyl) ester of chromic acid of the general formula ξΡ-Ο^Ηθ) (CgH^gSiOjgUi^ and a method and conditions for its preparation by conversion of 2-butyldiphenylchlorosilane with silver chromate or esterification of 2-butyldiphenylsilanol with chromium trioxide. The new chemical individual is identified and characterized by chemical analysis and analysis of electronic, infrared and NMR spectra. Its basic physicochemical quantities are determined.

Description

The invention relates to a previously undescribed compound of bis (2-butyldiphenylsilyl) chromic acid ester of the general formula [(2-C^H^) (CgH^jgSiO^CrOg) and a method for preparing this compound.

Chromic acid esters have not been of importance in recent years as active components of industrially used catalysts for olefin polymerization, especially for the production of low-pressure polyethylene. Purely organic chromic acid esters are not substitutes for organometallic esters, e.g. variously substituted silyl or stannyl derivatives, or organometalloid esters, e.g. substituted phosphonium esters of chromic acid. Of all the esters of this group, bis (triphenylsilyl) chromic acid ester and bis (triphenylstannous) chromic acid ester are of greatest practical importance. Similar catalytic properties can be expected from the alkyldiphenylsilyl derivative, bis (2-butyldiphenylsilyl) chromic acid ester. This compound has not yet been described in the literature.

The subject of the invention is the compound bis (2-butyldiphenylsilyl) chromic acid ester

The invention also provides a method for preparing bis(2-butyldiphenylsilyl) chromic acid ester, the essence of which consists in preparing 2-butyldiphenylchlorosilane of the structural formula

CHjCHCfigCHj where X represents chlorine, is reacted with silver chromate, or 2-butyldiphenylsilanol of the same structural formula, where X represents OH, is reacted with chromium oxide in an organic solvent environment.

In the preparation method according to the invention, the reaction is carried out in an environment of benzene, an aliphatic hydrocarbon - Οθ, preferably hexane, or a chlorinated hydrocarbon, preferably carbon tetrachloride, with which both 2-butyldiphenylsilyl components are well miscible, while the hexavalent chromium compounds form a solid phase.

The actual conversion takes place under mild conditions, i.e. at room temperature and atmospheric pressure, by shaking the reaction mixture for several hours. The product is isolated by vacuum evaporation of the solvent. The yields exceed 90% of theory.

The synthesis of the preparation is illustrated by the following examples.

Example 1

Preparation of bis(3-butyldiphenylsilyl)chromic acid ester from 2-butyldiphenylchlorosi2

212 828 lan and silver slag. The compound is formed by the reaction (2-0 ₄ Hg) (PgH ₅ ) ₂ SiCl + Ag ₂ 0r0 ₄ - [(2-0^) (CgHg) ₂ SiO] ₂ CrO ₂ + 2 AgCl

A mixture of 11 g of 2-butyldiphenylchlorosilane and 8 g of AgCrO ₄ in 100 ml of benzene was shaken intensively without access to light. The suspension formed by the reaction was filtered to remove insoluble silver salts. After vacuum evaporation of the solvent, 11.3 g of an orange oily product (94% of theory) was obtained. This substance can be prepared in dichloromethane with a yield of 92%. Example 2

Preparation of bis(2-butyldiphenylsilyl) ester of chromic acid from 2-butyldiphenyleilanol and chromium trioxide. The compound is formed by the reaction (2-C ₄ H ₉ ) (C ₆ H ₅ ) ₂ SiOH + CrO ₃ -t(2-C ₄ H ₉ ) (CgHg) ₂ Sio] ₂ CrO ₂ + H ₂ 0

A mixture of 6 g of 2-butyldiphenylethanol, 4 g of chromium trioxide and 5 g of anhydrous magnesium perchlorate in 80 ml of dry hexane was shaken vigorously for 1 hour in the absence of light. The resulting mixture was filtered and the orange-red filtrate was left overnight at 0 °C.

After further filtration, the clear solution was freed from solvent by vacuum evaporation. The product was obtained

6.8 g of an orange oily product (98% of theory).

The substance was prepared with a yield of 92, 96 and 98%, respectively, using tetrachloromethane, benzene and a-pentane as solvents.

Properties of bis(2-butyldiphenylsilyl) ester of ochromic acid and its identification.

Appearance and stability of the product: The prepared chromic acid ester is a pure orange oil stable in the dark below 0 °C. In light and on prolonged standing at room temperature, it decomposes into semi-solid dark brown products.

Specific gravity: 1128 kgm (at 20 °C)

Refractive index * 1.6097

Table I

Elemental analysis results for ^C 32 ^H 38 ^Si 2 ^CrO 4

Element content, % C I You Cr calculated 64.62 6.44 9.44 8.74 found 64.84 6.56 9.43 8.72

Electron spectrum

In agreement with the theory, three absorption bands were found in the region of 700 - 240 t in the spectrum of bis (2-butyldiphenylsilyl) ester of ochromic acid (hexane solution), the characteristics of which are given in Table II.

212 82S

Table 11

Characteristics of the bands of the electron spectrum. [(2-C ₄ H ₉ ) (CgH ₅ ) ₂ SiÓJ ₂ CrO ₂

Wavenumber (cm ) Wavelength 3(nm) molar absorption coefficient ÉClmol^cm“ ³ ) note l.belt 29,200 343 5.0.10 ³ 2nd belt 35,400 311 6,7.10 ³ fold 3rd belt 38,200 262 8,6.10 ³ the belt has a fine structure

The positions of the bands and their intensities correspond to the results found for known triphenyl, trialkyl, and alkyldiphenylsilyl esters of chromic acid.

Infrared spectrum

In the infrared spectrum of the ester, absorption bands were found in the region of 400 - 4,000 ^cm3 , the wavenumbers and assignments of which are given in Table III.

In the infrared spectrum, bands belonging to the vibrations of the phenyl group, 2-butyl group, Si-0 bond vibration and CrO^ group vibration were clearly identified. Their assignment resulted from vibrational analysis and comparison with the spectra of (2-C^Hg) (CgH-g) ₂ SiCl, (2^0^11^) < ^c eH^) ₂ SiOH,|^(GgH^)^Sio| 2 ^C;rO 4 and other organometallic esters of chromic acid.

Table III

Infrared spectrum of bis(2-butyldiphenylsily) chromic acid ester

abs.waist (cm' ³ ) assignment abs.waist (cm ^-3 ) 470 m X-senz 1450 vs. 502 vs. X-senz 1477 m 541 m 6(C-C) 1581 m 593 m V(Si-O-Cr) 1760 vw Sy 616 in á»(0CC)Ph 1810 W 640 sh X-senz 1875 * ř 694 vs. breathing circle 1950 » J 703 vs. K(C-H)Ph 2867 Θ 731 m V(Si-C) 2900 sh 768 w J (CH ₂ ) 2927 with > 842 sh (C-H)Ph 2958 vs , 870 vs-b V(Si-O) 2996 m Ί 968 vs. Y(Cr-O) 3010 m [

assignment <Í(CH ₃ ) v(CC)Ph

V(C-C)Ph comb.

harm and

ý(C-H)Ph

Y(C-H)Bu

212 82»

980 in Y(Cr-0) 3020 circle def. Y(C-H)Ph 991 m Ph 3044 with * 1024 m a(c-H)Ph 3062 8 1062 m ft(C-H)Ph 3080 sh > 1114 in X-senz Ph Ph - renyl 1150 sh (3 (C-H)Ph Bu - 2-butyl 1184 m (3 (C-H)Ph X-senz - band sensitive to substitution 1200 w X (CH ₃ ) 1255 w β (C-H)Ph Band intensities 1298 w (3(C-H)Ph VW - very weak 1325 w Y(C-C)Ph w - weak m - medium 1371 m <$ (ch ₃ ) with - strong 1421 in <(C-C)Ph vs. - very strong b - wide sh - fold ¹³ c V-hInmr and ? ³ Si 1¼ 1 NMR spectrum

The C H NMR spectrum of the compound was measured at a frequency of 25.047 MHz, and the Si Ti NMR spectrum at a frequency of 19.738 MHz. A 25% solution of the compound in deuteriochloroform and tetramethylsilane as an internal standard were used for the measurement ^. The measurement was performed at a temperature of 25 °C. The chemical shift values are expressed in ppm (positive values indicate a shift to a lower field).

CHjCHg-CH-CHj 7 6 5 8

^cP-hJnmR spectrum <í (σ,ρ « 133.3 <f (C ₂ ) . 134.7 <qo ₃ ) « 127.9 J (C ₄ ) . 130.2

J (C ₅ ) - 21.8 Λθ ₆ ) - 24.u <f(C _? ) - 13.3 or 13.2 <Γ(0 ₈ ) - 13.3 or 13.2

212,828 ^SSi^H^NMR spectrum -S(Si) = 9.6

Claims (3)

SUBJECT OF THE INVENTION 1. Compound chromic acid bis (2-butyldiphenylsilyl) ester of structural formula 2. A process for the preparation of a compound according to claim 1, which comprises 2-butyldiphenylchlorosilane of the structural formula Ό O> - Siš- X Wherein X is chlorine is reacted with silver chromate, or 2-butyldiphenylsilanol of the same structural formula wherein X is OH is reacted with chromium trioxide in an organic solvent environment. 3. Process according to claim 2, characterized in that the medium used is benzene or an aliphatic hydrocarbon, preferably hexane or an optionally chlorinated hydrocarbon, preferably carbon tetrachloride. FIXED DESCRIPTION OF THE INVENTION TO AUTHORIZATION CERTIFICATE No. 212 828 Int.Cl? OJ C 07 K 11/00 In the description of the invention for the author's certificate No. 212 628, the name of the fourth author is improperly printed. Place: ..KLIKORA JIŘÍ prof.ing., Correct: KLIKORKA JIŘÍ prof.ing.,