WO1995033776A1

WO1995033776A1 - Novel organo-metallic compounds, methods for preparing same, and a method for the polymerization of unsaturated hydrocarbons using said organo-metallic compounds as catalysts, as well as novel semi-products and catalyst preparations

Info

Publication number: WO1995033776A1
Application number: PCT/NL1995/000202
Authority: WO
Inventors: Michael Franz Lappert; Dimsheng Liu
Original assignee: Specs And Biospecs B.V.
Priority date: 1994-06-07
Filing date: 1995-06-07
Publication date: 1995-12-14
Also published as: AU2579895A

Abstract

The invention relates to organo-metallic compounds according to the formula (1; 1a, 1b, 1c) of the formula sheet, wherein M is Zr, Ti or Hf; Xn represents a group that can be readily isolated, whereby n = 2 or 3 for example a halogen atom; R?1 and R5¿ are preferably Si(CH¿3?)3 or C(CH3)3; R?2¿ is a tertiary alkyl group, for example C(CH¿3)3; R?3 is a hydrogen atom or a low alkyl group; and R4 is a phenyl group. These compounds are suitable for the polymerization of alkenes, such as ethene or propene. They possess a satisfactory catalytic activity and can be prepared in a simple manner.

Description

NOVEL ORGANO-METALLIC COMPOUNDS, METHODS FOR PREPARING SAME, AND A METHOD FOR THE POLYMERIZATION OF UNSATURATED HYDROCARBONS USING SAID ORGANO-METALLIC COMPOUNDS AS CATALYSTS, AS ^"WELL AS NOVEL SEMI-PRODUCTS AND CATALYST PREPARATIONS.

There are numerous catalysts for the polymerization of alkenes. An important group are the metallocenes, as refer¬ red to in Chemistry in Britain, February 1994, namely Cp₂ZrCl₂ (wherein Cp = cyclopentadienyl) and those according to formulas (3) , (4) and (5) . The metallocenes have numerous advantages: they may be used for controlling the stereo- regularity and the distribution of the molecular weight while obtaining polymers which are "tailored" to certain applications, and they are soluble in hydrocarbons, whereby they form homogeneous catalytic systems.

The above compounds are suitable for use as catalysts for the polymerization (both homopolymerization and copolymeri- zation) of alkenes, for example etheen of propene.

What vvas found was a group of new compounds which are also very suitable for polymerizing unsaturated hydrocarbons.

The present novel cyclopentadienyl-free polymerization catalysts possess a usable and distinguishing catalytic activity and can be prepared in a very simple manner.

The compounds have the structure according to the general formula 1 of the formula sheet, and in particular according to formulas la, lb, or lc of the formula sheet, whereby the significance of the symbols used therein is as indicated in the claims.

Preferred are compounds according to formula la, wherein signifies Zr, R represents a phenyl group or a naphtalene group, which groups may both be substituted, R, represents a t. butyl group, X is a halogen atom and Q signifies -N- Si (CH,)₃.

Especially preferred are compounds according to formula 2a of the formula sheet wherein Bu^"- represents a t. butyl group and R represents a phenyl group or a naphtalene group, which groups may both be substituted.

The invention relates in particular to compounds according to formula 3a of the formula sheet, wherein Bu^c represents a t . butyl group and R, may be a hydrogen atom or another substituent. The compounds in which R, represents a hydrogen atom of a p-methyl group are to be preferred thereby.

Another preferred compound is the one according to formula 4a of the formula sheet, wherein Bu^"' represents a t. butyl group.

The invention furthermore relates to methods for the poly- merization of unsaturated hydrocarbons, in particular ethene and propene, using the novel organo-metallic com¬ pounds according to the invention.

Furthermore the invention relates to methods for the prepa- ration of the novel organo-metallic compounds, and also to the novel intermediate products produced during said process .

The novel intermediate products have the structure according to formula 5a of the formula sheet, wherein the significance of R, R_: and Q is as indicated before and wherein Y represents an alkali metal, preferably potassium.

The invention furthermore relates to catalytically active preparations, which contain the novel organo-metallic compounds according to the invention as the active consti¬ tuent, either in the form of a solution or bonded with a fixed carrier.

An advantage of the novel organo-metallic compounds accor¬ ding to the invention is that their catalytic action is better than that of the existing polymerization catalysts.

In another embodiment the invention provides organo-metal¬ lic compounds according to the formula (lb) , wherein Q represents -N-Si(CH₃)₃ or -C (H) -Si (CH₃) ₃; R represents an alkylene group or an arylene group; R' represents a t.butyl group or a t.pentyl group; M represents Zr, Ti or Hf; and A represents a group that can be readily isolated.

Preferably Q is -N-Si (CH₃) ₃; R is an ethylene group or an o- phenylene group, which may or may not be substituted, whereby the possible substituent to the o-phenylene group is preferably present at location 3 or location 4; R' is a t.butyl group; M is Zr; and A is a halogen atom.

In particular the invention provides a compound having the formula (2b) , whose molecular formula is Zr [{N(R)C(Bu^c)CH}₂C₆H. - 1.2] Cl₂. (Bu^c = tert .butyl)

The invention furthermore provides organo-metallic com- pounds according to formula (lc) of the formula sheet, wherein R¹ and R⁵ are identical or different from each other and wherein each of said symbols represents a group C(C₁-C₄ alkyl) ₃ or Si ( C₁-C₁ alkyl) ₃, wherein each of the alkyl groups may be substituted by one or more phenyl groups, or a group C-C₆H₅(C₁-C₄ alkyl) ₂, a group C (C₆H₅)₂ (C₁-C₄ alkyl) or a group C(C_εH₅)₃, wherein C₆H₅ is a phenyl group; R² repre¬ sents a tertiary alkyl group having its tertiary carbon atom bonded with the diketinimato system; R³ represents a hydrogen atom or a C₁-C₃ alkyl group; R⁴ represents a phenyl group or a phenyl group substituted by one or more C_x-C₄ alkyl groups; is Zr, Ti or Hf; and A represents a group that can be readily isolated. Preferably R^: and R⁵ are Si(CH₃)₃ or C(CH₃)₃; R² is C(CH₃)₃ or C (CH₃) ₂C-,H₅; R³ is a hydrogen acorn; R^** is C₆H₅ (phenyl) or C₆H₅CH₃-4 (a 4-tolyl group) ,- and A is halogen.

More preferably R¹ and R⁵ are both Si(CH₃)₃; R² is C(CH₃)₃; R³ is hydrogen; R⁴ is C₆H_E; M is Zr; and A is Cl .

Each of the above compounds can suitably function as a catalyst for the polymerization (both homopolymerization and copolymerization) of alkenes, for example ethene or propene.

The invention will be explained in more detail below with reference to the following examples:

Example 1

Preparation of H₃C(SiMe₃)C₆H₅.

17.3 g (0.137 mol) PhCH.Cl in 30 ml. Et₂0 was added in drops to a suspension of 4.0 g (0.165 mol) Mg in 150 ml. Et₂0 in a flask provided with a reflux cooler over a period of three hours. The mixture obtained was stirred for twelve hours, after which the remaining Mg was removed by filtration. Then 14.9 g (0.137 mol) SiMe₃Cl at room temperature was added to the filtrate in drops. The mixture was refluxed for eight hours and then treated with water. The organic phase was dried over CaCl₂. Distillation at 40-41°C under 1 mm. mercury pressure resulted in 16.0 g (71%) H₃C (SiMe₃) C₆H₅. ^lH NMR (360 MHz, CDCL₃) : 0.00 (s, 9H) , 2.08 (s, 2H) , 6.99^" (d, 2H) , 7.04 (t, 1H) , 7.19 (d, 2H) .

Example 2

Preparation of [Li/tmeda) ] [CH(Ph)C(Ph)N(SiMe₃) ] ]

73 ml. (1.6 mol) LiBu^r' was slowly added to 19.0 g (0.116 mol) H₂C(SiMe₃) C_fH₅ and 17 ml. tmeda (0.116 mol) in 60 ml. pentane at room temperature. The mixture was stirred for twelve hours and then filtrated. The precipitate of [Li/tmeda) ] [CH (SiMe₃) C₆H₅] was dried. Yield 27.0 g (81%) . 2 ml. PhCN (20.0 mmol) was added, by means of a syringe, to 5.7 g [Li/tmeda)] [CH(SiMe₃) C₆H (19.93 mmol) in 30 ml. pentane at room temperature. The mixture was stirred for six hours and then filtrated, whereby a yellow solid was formed, namely [Li/tmeda) ] [CH(Ph) C (Ph)N(SiMe₃) ] . Yield 7.0 g (90%) .

^XH NMR (360 MHz, C₆D₆) : 0.31 (s, 9H) , 5.53 (s, 1H) , 6.79 (t, 1H) , 7.11 (m, 4H) , 7.23 (m, 1H) , 7.82 (d, 2H) , 8.12 (m, 2H) , (tmeda) 1.41 (s, 4H) , 1.68 (s, 12H) .

Example 3

Preparation of K[CH(Ph)C(Ph)N(SiMe₃) ]

Following the procedure described in example 2 4.1 ml. PhCN (40.58 mmol) was added, by means of a syringe, to 12.0 g

[Li/tmeda)] [CH(SiMe₃) C₆H (41.96 mmol) at room temperature. The mixture was stirred for four hours, after which 5.1 g KOBu"- (41.73 mmol) was added. The mixture was stirred for twelve hours and then filtrated. The precipitate was washed with approx. 30 ml. hexane. Yield 14.3 g (94%) K[CH(Ph)C(Ph)N(SiMe₃) ] , a yellow solid.

^XE NMR (360 MHz, d8-pyridine) : 0.24 (s, 9H) , 5.50 (s, 1H) , 6.81 (t, 1H) , 7.25 (m, 5H) , 7.72 (d, 2H) , 8.50 (b, 2H) .

Example 4

Preparation of tCH(Ph)C(Bu^t)N(SiMe₃) ]

57 ml. LiBu¹¹ (1,6 mol) was slowly added to 14.8 g H₂C(SiMe₃) C₆H₅ (0.090 mol) and 13.6 ml. tmeda (0.090 mol) in

150 ml pentane at room temperature. The mixture was stirred for twelve hours. Subsequently 9.9 ml Bu^cCN (0.090 mol) was added and stirring was continued for four hours. Then 11.0 g KOBu^'- (0.090 mol) was added and the new mixture was stir¬ red for twelve hours. The white precipitate obtained, which consisted of K [CH (Ph) C(Bu^*-)N(SiMe₃) ] , was washed with 50 ml. pentane and then dried in vacuum. Yield 25.5 g (99%) ^λK NMR (360 MHz, d8-pyridine) : 0.53 (s, 9H) , 1.43 (ε, 9H) , 5.63 (s, 1H) , 6.81 (t, 1H) , 7.29 (t, 2H) , 7.82 (d, 2H) .

Example 5

Preparation of [Zr{CH(Ph) C(Bu^'-)N(SiMe₃) }cl₃]

0.70 g ZrCl, (3.00 mmol) was added to a solution of 1.60 g K[CH(Ph)C(Bu^c)N(SiMe₃) ] (5.60 mmol) in 30 ml Et₂0 that was chilled to -78° C. The mixture was stirred for fourteen hours and then filtrated. The Et₂0 was removed from the filtrate in vacuum, after which 30 ml toluene was added to the oily residu. Then 0.9 g ZrCl_< (3.86 mmol) was added to this solution at 25° C. The mixture was heated to 75-80° C. for twelve hours while being stirred. The solvent was removed in vacuum and the residu was extracted with 2x 20 ml. CH-C1-. The filtrate was dried in vacuum, whereby a yellow crystalline K[CH(Ph) C (Bu^c)N(SiMe₃) was formed. Yield 2.50 g(100%) . 'H NMR (360 MHz,) : 0.49 (s, 9H) , 1.35 (s, 9H) , 6.70 (s, 1H) , 7.48 (m, 4H) , 7.61 ( , 1H) .

Example 6

Preparation of Zr[CH(P )C(Ph)N(SiMe₃)Cl₃]

1.20 g ZrCl, (5.15 mmol) was added to 1.30 g

K[CH(Ph) C(Ph)N(SiMe₃) ] ^' in 40 ml. toluene while being chilled to -78° C. The mixture was stirred for fourteen hours and then filtrated. The filtrate was concentrated and then put in a separate place at room temperature for a week, after which Zr [CH(Ph) C(Ph)N(SiMe₃) Cl₃] was formed as yellow crys- tals. Yield 1.17 g (59%) .

^!H NMR (360 MHz, CDCl₃) : 0.33 (s, 9H) , 6.03 (b, IK) , 6.73 (b, 2H) , 7.15 (m, 2H) , 7.41 (m, 2H) , 7.47 (m, 2H) , 7.69 (2H) .

Example 7

Preparation of [Zr{N(SiMe₃) C (Bu^r)C(SiMe₃) } (μ-Cl)₂C1] -

1.20 g ZrCl, (3.73 mmol) was added to 2.41 Zr[N(Si

Me₃)C(Bu^c)C(SiMe₃) }₂C1₂] ^x* (3.73 mmol) in 35 ml. toluene. The mixture was heated to 50° C. for four hours while being stirred, and then filtrated. Concentration resulted in 2.90 g Zr [N(SiMe₃)C(Bu^c)C(SiMe₃) } (μ-Cl)_.Cl], (80%) in the form of white crystals.

Η NMR (360 MHz, CDCl₃) : 0.25 (s, 9H) , 0.56 (s, 9H) , 1.29 (s, 9H) , 5.25 (s, 1H) ; ⁱ³C NMR (250 MHz, CDCl₃) : 0.95, 3.42, 29.50, 41.64, 105.39,

192.01.

Example 8

Preparation of H₂C (SiMe₃) C₆H_sMe-p

A solution of 25 g BrCH₂C₆H_EMe-p (0.132 mol) in 30 ml Et₂0 was slowly added in drops to a suspension of 4.5 g Mg (0.188 mol) in 140 ml Et₂0 in a flask provided with a reflux cooler over a period of 1 hour. The mixture obtained was furthermore stirred for 12 hours and filtrated so as to remove any unconverted Mg. Then 14.4 g SiMe₃Cl (0.133 mol) was added to the filtrate in drops at room temperature. This mixture was refluxed for 8 hours and then treated with water. The organic layer was dried over CaCl₂. Distillation at 56-60°C and 1 mm mercury pressure resulted in 16.2 g

^x* This compound is described in an article by the inventors in J. Chem. Soc. , Chem. Comm. , 1994, 2637 H₂C(SiMe,)C₆H₅Me-p (yield 69%) .

Example 9

Preparation of [K{CH(C₆H₅Me-p) C(Bu^t)N(SiMe₃) }]_a

33 ml LiBu_n (1.6 mol) was slowly added to 9.46 g

H₂C(SiMe₃) C₆H₅Me-p (0.053 mol) and 8 ml tmeda (0.053 mol) in

130 ml hexane at room temperature. The mixture was stirred for 6 hours, after which 5.5 ml Bu^fcCN (0.050 mol) was added and stirring was continued for two hours. After this 6.4 g KOBu^c (0.052 mol) was added and the new mixture was stirred for 12 hours. 13.9 g K{CH(C₆H₅Me-p) C(Bu*^")N(SiMe₃) }_n was obtained by filtration, washed with 40 ml hexane and dried in vacuum (yield 91%) .

Example 10

Preparation of [Zr{CH (C₆H₅Me-p) C (Bu ) N (SiMe₃) }]

An amount of 1.50 g Zr(Cl₄ (6.44 mmol) was added to 2.62 g [K{Ch(C₅H₅Me-p)C(Bu^t)N(SiMe₃) }]_n (9.13 mmol) in 30 ml Et₂0 while being chilled to -78°C. The mixture was stirred for

14 hours and then filtrated. The Et₂0 was removed in vacuum. 30 ml toluene was added to the oily residu (2.70 g) and then 1.20 g ZrCl₄ (5.15 mmol) was added at 25°C. The mixture was heated to 75-80°C for 12 hours while being stirred. The solvent was removed in vacuum and the residu was extracted with 30 ml CH₂C1₂. After the solvent had been removed in vacuum yellow crystals of [Zr{CH(C_εH_EMe-p) C(Bu"^"-) N(SiMe₃) }]^" were formed. Yield 2.80 g (69%) .

Η NMR (360 MHz, CDCl₃) : δ 0.46 (s, 9H) , 1.34 (s, 9H) , 2.46 (s, 3H) , 6.57 (s, 1H) , 7.32 (m, 4H) .

Example 11

Preparation of 1-H-C (SiMe₃) C₁₀H₇ A solution of 25 g 1-H₂C (Cl) C_1CH₇ (0.142 mol) in 30 mi Et₂0 was added in drops to a suspension of 3.5 g Mg (0.146 mol) in 140 ml Et₂0 over a period of 2 hours (in an apparatus provided with a reflux cooler) . Then the mixture was stir- red for 12 hours, whereby a yellow precipitate was formed. The remaining liquid was poured off and 30 ml thf was added. Then 15 g SiMe₃Cl (0.138 mol) was added in drops at 0°C. The mixture was stirred for 12 hours and then treated with water. The organic layer was separated and dried over CaCl₂. Distillation at 104-108°C under 1 mm mercury pressure resulted in 1-H₂C (SiMe₃) C₁₀H₇. Yield 20.4 g (95%) .

Example 12

Preparation of [K{CH(C₁₀H₇) C(Bu⁶)N(SiMe₃) }]_n

An amount of 33 ml LiBuⁿ (1.6 mol) was slowly added to 10.4 g l-H₂C(SiMe₃) C₁₀H₇ (0.049 mol) and 7.4 ml tmeda (0.049 mol) in 80 ml pentane at -10°C. The mixture was stirred for 1 hour, after which 5.3 ml Bu^cCN (0.049 mol) was added and stirring was continued for 2 hours. Then 5.30 g KOBu^c (0.044 mol) was added and the new mixture was stirred for 12 hours. After filtration a yellow crystallyne precipitate consisting of K{Cl (C₁₀H₇) C(Bu^c)N(SiMe₃) } was obtained, which was successively washed with 40 ml pentane and with 30 ml

Et₂0 and which was then dried in vacuum. Yield 11.9 g (67%) .

Example 13

Preparation of [Zr{CH(C₁₀H₇)C (Bu^t)N(SiMe₃) >C1₃]

An amount of 1.00 g ZrCl₄ (4.29 mmol) was added to 2.4 g [K{CH(C₁₀H₇)C(Bu^t)N(SiMe₃) }] _n (7.14 mmol) in 40 ml Et₂0 while being chilled to -78°C. The mixture was stirred for 14 hours and then filtrated. The Et₂0 was removed from the filtrate in vacuum and 30 ml toluene was added to the oily residu. Then 0.9 g ZrCl₄ (3.86 mmol) was added at 25°C. The mixture was heated to 75-80°C for 12 hours while being stirred. The solvent was removed in vacuum and the residu was extracted with 40 ml CH₂C1₂. The filtrate was dried in vacuum, whereby yellow crystals of Zr(CH(C_lcH₇C)C(Bu^c)N(SiMe) }C1₃ were formed. Yield 1.8 g (51%) .

'H NMR (360 MHz, CDC1₃) : δ 0.39 (s, 9H) , 1.49 (s, 9H) , 7.10 (s, 1H) , 7.58 (m, 3H) , 7.80 (d, 1H) , 7.91 (d, 1H) , 7.96 (d, 1H) , 8.15 (d, 1H) .

The catalytic action of the novel compounds according to the invention was examined on the basis of the polymeri¬ zation of ethene. For that purpose the compounds to be examined were dissolved in 50 ml. toluene and contacted with ethene under a pressure of 0.56 bar. The results are summarized in table 1.

TABLE 1

Test results of the polymerization of C₂H₄

Catalyst* time temp. MAO AlMe₃ Polymer (mg) (g) (g) (g)

PI (22) 50 min ~ 60°C 0,54 18,6

P2 (22) 4 uur 25-30°C 0,54 0,78

P3 (20) 4 uur 25-30°C 0,54 1,1

P4 (17) 4 uur 25-30°C 0,52 1,6

P5 (22! 70 min 0,54 13,1

*

PI [Zr{CH(Ph)C(Bu^c)N(SiMe₃) }C1,] P2 [Zr{CH(Ph)C(Ph)N(SiMe₃) }Cl₃] P3 [Zr{N(SiMe₃)C(Bu^t)N(SiMe₃) }Cl₃] P4 [Zr{N(SiMe,)C(Bu^t)CH}-C_«H,-o}Cl-] P5 [ZrCp.Cl-] The action of one of the novel compounds (Pl) was also examined on the basis of the polymerization of C₆H₁₂. The results are summarized in table 2.

TABLE 2

Test results for the polymerization of C_SH_1:

Catalyst* time temp. toluene C₆H₁₂ MAO oily (mg) hrs ml ml (g) product (g)

PI (2.3: 1 25 ° C 47 4 0 . 24 0 . 50 PI (22) 2 50 ° C 47 4 0 . 24 0 . 36

A few compounds according to the invention were tested for their action in the polymerization of propene. To this end said compounds were dissolved in toluene and contacted with the C₃H₆ under a pressure of 0,56 bar. The polymerization reaction was initially exothermic and produced so much heat at P_x en P₆, that cooling to 60°C was necessary. The results of this test are shown in table 3.

TABLE 3

Results of the polymerization of C₃H_e

Catalyst* time temperature MAO Polymer (mg) hrs (g) (g)

Pi (20) ^' 1 25~60°C 0,5 6, 0 p₆ (16) 1 25~60°C 0,5 5,1 p₇ (16) 1 25~40°C 0,5 1,6

P₆ = [Zr{CH(C₆H₅Me-ρ)C(Bu^c)N(SiMe₃) }] P₇ = [Zr{CH(C₁₀H₇)C(Bu^t)N(SiMe₃) }C1₃]

The structure of a few of the novel compounds according to the invention was determined via X-ray analysis. The struc¬ ture of [Zr{CH(Ph)C(Bu^c)N(SiMe₃) }C1₃] is shown in Figure lb, and the structure of the corresponding naphtalene compound is shown in Figure 2b.

The intramolecular distances (in Angstrom) and the angles (in degrees) of the latter compound are included in the table below.

Table 4

Intramolecular distances (A) and angles (°) of [Zr{CH(C₁₀H₇)C(Bu^c)N(SiMe₃) }C1₃] ; the estimated standard 5 deviations are mentioned between brackets.

Zr -N 2 050 3) Zr-Cl (3) .371 (1) Zr -Cl 2 374 1) Zr-Cl (2) .379 (1)

Zr-C(l) 2 499 3) Zr-C(2) .621 (3) Zr-C(3) 2 779 3) Si-N .755(3) Si-C(19) 1 848 4) Si-C(18) .853 (5) Si-C(17) 1.864 4) N-C(l) 1 401 (3) C(l) -C(2) 1, 361 4) C(l) -C(13) 1 538 (4) C(2)-C(3) 1.473 4) C(3) -C(4) 390 (4) C(3) -C(12) 1.446 (5) C(4) -C(5) 408 (5) C(5) -C(6) 1.362 (6) C(6) -C(7) 397(6) C(7) -C(12) 1.421 (5) C(7) -C(8) 431 (6) C(8) -CO) 1.339 (7) C(9) -C(10) 388 (7) C(10) -C(ll) 1.365 (5) C(ll) -C(12i 416 (5) C(13) -C(15) 1.527 (5) C(13) -C(16! 529 (5) C(13) -C(14) 1.535 (5)

N- -Zr- CK3) 119 32 (7) N-Zr- Cl(l) 95 .35(7)

Cl (3) -Zr-Cl (1) 95 65 (4) N-Zr- Cl(2) 127.49 (7)

Cl(3) -Zr-Cl (2) 110 01(5) Cl(l) -Zr-Cl (2) 96.73 (4)

N- -Zr-C(l) 34 11(9) Cl(3) -Zr-C( 1) 137.04 (7)

Cl (l) -Zr-C (1) 115 16(7) Cl(2) -Zr-C( 1) 95.94 (8)

N- -Zr-C(2) 59 30 (10) Cl(3) -Zr-C( 2) 117.89 (7)

Cl (1) -Zr-C (2) 144 50 (7) Cl(2) -Zr-C( 2) 83.10(8) c ⁽D-Zr-C(2) 30 71(9) N-Zr- C(3) 73.94 (10)

^ 1 - (3) -Zr-C(3) 86 40 (7) Cl(l) -Zr-C( 168.55(7)

Cl(2) -Zr-C(3) 93 12 (7) C(D- Zr-C(3 57.74 (9)

C(2) -Zr-C(3) 31 50(9) N-Si- C(19) 105.0(2)

K- -Si-C(18) 113 7(2) C(19) -Si-C( 18) 108.3(2)

N- ^■Si-C(17) 109 7(2) C(19) -Si-C(17) 109.1(2)

C I :i8) -Si-C(17) 110 8 (2) C(l) - N-Si 136.7(2)

C ι :i) -N-Zr 90 8(2) Si-N- Zr 132.47 (13)

C(2) -C(l) -N 117 6(3) C(2)- C(l) -C (13) 121.6(3)

N- ^■C (l) -C(13) 120 1(3) C(2)- C(l) -Zr 79.6(2)

N- ^■C (l) -Zr 55 10 (14) C(13) -C(l) Zr 128.7(2)

C ( :D - C(2) -C(3) 129 1(3) C(l) - C(2) -Zr 69.7(2)

C! :3)-C(2) -Zr 80 (2) C(4)- C(3) -C (12) 119.1(3)

Cl ;4) -C(3) -C(2) 121 (3) C(12) -C(3) C(2) 119 .3 (3) C(3) -Zr 95 (2) C(12) -C(3) Zr 111 6 (2) C(3) -Zr 68 (2) C(3)- C(4) -C (5) 120 7 (4) C(5) -C(4) 120 (4) C(5)- C(6) -C (7) 121 9 (4) C(7) -C(12) 119 (4) C(6)- C(7) -C (8) 122 2 (4)

-2) -C(7) -C(8) 118 (4) C(9)- C(8) -C (7) 121 514) C(9) -C(10) 120 (4) C(ll) -C(10) -C(9) 120 8 :5)

10) -C(ll) -C(12) 121 4) C(ll) -C(12) -C(7) 117.7(3) 11) -C(12) -C(3) 123 3) C(7)- C(12) - C(3) 118.8(3) C(15) -C(13) -C(16) 108 3) C(15) -C(13) -C(14! 110.1(3) C(16) -C(13) -C(14) 108 3) C(15) -C(13) -C(l) 109.4(3) C(16) -C(13) -C(l) 112 .2(3) C(14) -C(13) -C(l) 108.6(3) 1 A

Example 14

Preparation of the Zr-co pound according to formula (2b) .

The starting material for this synthesis was Li₂ (TMEDA) ₂{l.2-C₆H₄(CHSi(CH₃)₃)₂}, wherein TMEDA=tetramethyl ethylenediamine, Me₂NCH₂CH₂NMe₂. This compound was prepared in the manner described in an article by M.F. Lappert c.s., Inorg. Syth. , 1989, 26, 144. The compound was converted with Bu^cCN, providing [Li₂ (TMEDA)₂{l .2-C₆H₄ (CHCBu^tNSi- (CH₃)₃)₂}] , which latter compound was in turn converted with potassium t.butoxide into the corresponding potassium deri¬ vative; reacting the potassium compound with ZrCl₄ resulted in the compound having the formula (2) , Zr[{N(Si(CH₃)₃)C(Bu^t)CH}₂C₆H₄-1.2]Cl₂.

Example 15

Preparation of Li- (TMEDA)₂{o.C₆H₄CHCBu^cNSi (CH₃)-}

Bu^tCN (1.39 ml, 12.6 mmol) was added in drops to a solution of [Li₂ (TMEDA)₂{l.2-C₆H₄(CHSi(CH₃),)₂}] (3.1g. 6.28 mmol) in Et₂0 (approx. 40 ml) at approx. 25°C while stirring. The orange solution obtained was stirred for 12 hours. Volatile material was removed at 90°C/10^"2 Torr and the residu was incorporated in hexane by extraction (approx. 50 ml) . The filtrated extract was concentrated, providing yellow crys¬ tals of the title compound (3.1 g, 75%) .

Example 16^'

Preparation of K₂ (TMEDA) ₂{ l . 2 -C₆H₄ (CHCBu^fcNSi (CH₃ ) ₃ ) - }

Hexane (approx. 30 ml) was added to a mixture of the above- obtained lithium compound (1.86 g, 2.82 mmol) and KOBu^t (0.80 g, 6.55 mmol) at 25°C while stirring. The mixture was heated at 60°C for half an hour and then stirred at 25°C for 12 hours, which resulted in the formation of a bright yellow precipitate, which was separated by filtration and dried in vacuum. The residu consisted of the desired potas- sium compound (1.60 g, 93%) .

Example 17

Preparation of Zr ( {N ( Si (CH₃) ₃ ) C (Bu^fc) CH>₂C₆H₄- 1 . 2 ) Cl₂

Zirconium(IV) chloride (0.37 g, 1.59 mmol) was added to a solution of the above-prepared potassium compound (0.86 g, 1.42 mmol) in toluene (approx. 25 ml) accompanied by stir¬ ring and chilling (-78°C) . The mixture was slowly heated to room temperature, then heated at 70°C for 2 hours and furthermore stirred for another 12 hours. The white preci¬ pitate was separated by filtration. Concentration of the filtrate resulted in pale yellow crystals of the final zirconium compound Zr{N(R) C (Bu^c) CH}₂C₆H₄-1.2) Cl₂ (0.76 g, 93%) . The molecular structure became apparent from the X- ray diffraction pattern of a single crystal, see table 5 and the structural formula (6b) below.

Table 5

Intramolecular distances (A) and angles (°) _; estimated standard deviations are mentioned between brackets. a) Bonds

Zr-Cl (1) 2.443 (1) Zr-Cl (2) 2.385(1)

Zr-N(l) 2.175 (3) Zr-N(2) 2.167 (3)

Zr-C(l) 2.561(4) Zr-C(2) 2.470 (3)

Zr-C(3) 2.632 (3) Zr-C(8) 2.674 (3)

Zr-C(9) 2.509(3) Zr-C(lO) 2.560 (3)

Si(l)-N(l) 1.753 (3) Si(l) -C(ll) 1.862 (5)

Si(l) -N(12) 1.860(4) Si(l) -C(13) 1.851(5)

Si (2) -N(2) 1.755 (3) Si (2) -C(14) 1.859(5)

Si (2) -C(15) 1.849(5) Si (2) -C(1G) 1.858 (4)

N(l)-C(l) 1.359(4) N(2) -C(10) 1.362 (4)

C(l) -C(2) 1.387(5) C(l) -C(17) 1.539(5)

C(2) -C(3) 1.488 (5) C(3) -C(4) 1.403 (6)

C(3)-C(8) 1.399(5) C(4)-C(5) 1.370(6)

C(5)-C(6) 1.377(7) C(6) -C(7) 1.370(6)

C(7)-C(8) 1.403 (5) C(8) -C(9) 1.487(5)

CO) -C(10) 1.384(5) C(10) -C(21) 1.528 (5)

C(17) -C(18) 1.525(7) C(17) -C(19) 1.509(6)

C(17) -C(20) 1.519(6) C(21) -C(22) 1.525(6)

C(21) -C(23) 1.523 (6) C(21) -C(24) 1.536 (6) b) Angles

Cl(l) -Zr-Cl (2) 93.77(4) Cl(l) -Zr-N(l) 84.75 (7)

Cl(l) -Zr-N(2) 84.74 (6) Cl(l) -Zr-C(l) 113.92 (7)

Cl(l) -Zr-C(2) 143.95(9) Cl(l) -Zr-C(3) 136.02 (7)

Cl(l) -Zr-C(8) 136.56(7) Cl(l) -Zr-C(9) 143.43 (9)

Cl (1) -Zr-C(lO) 113.62 (7) Cl(2) -Zr-N(l) 105.07 (8)

Cl (2) -Zr-N(2) 106.10(8) Cl(2) -Zr-C(l) 89.54 (8)

Cl(2) -Zr-C(2) 96.08(9) Cl(2) -Zr-C(3) 126.53 (7)

Cl (2) -Zr-C(8) 125.78(7) Cl(2) -Zr-C(9) 96.10(9)

Cl (2) -Zr-C(lO) 89.76(8) N(l) -Zr-N(2) 147.6(1)

N(l) -Zr-C(l) 32.06(9) N(l) -Zr-C(2) 59.2 (1)

N(l) -Zr-C(3) 69.6 (1) N(l) -Zr-C(8) 99.3 (1)

N(l) -Zr-C(9) 125.8 (1) N(l) -Zr-C(lO) 155.9(1)

N(2) -Zr-C(l) 155.2 (1) N(2) -Zr-C(2) 125.0(1)

N(2) -Zr-C(3) 98.1(1) N(2) -Zr-C(8) 68.8 (1)

N(2) -Zr-C(9) 58.7(1) N(2) -Zr-C(lO) 32.24 (9)

C(l) -Zr-C(2) 31.9(1) C(l) -Zr-C(3) 57.2 (1)

C(l) -Zr-C(8) 86.4 (1) C(l) -Zr-C(9) 101.3 (1)

C(l) -Zr-C(lO) 132.4 (1) C(2) -Zr-C(3) 33.7(1)

Ethene was polymerized, using the above-prepared zirconium compound in an amount of 15 mg and methyl aluminium oxane

(MAO) as a co-catalyst in an amount of 400 mg. The reaction was started at room temperature, and the maximum temperatu¬ re caused by the exothermioc reaction was 70°C. Furthermore a test was carried out with ZrCp₂Cl₂ as a reference cata- lyst. The test conditions and the result are included in table 6 below .

Table 6

Weight of Weight Molec . Pressure Weight compound MAO ratio ethene polymer

(mg) (mg ) Zr : Al (bar ) (gram)

Compound

formula ( 2b ) 15 400 1 : 265 init . press 10 9 . 8 end press . 6

ZrCp₂Cl₂ 20 2000 1:503'' init. press. 3.6 end press . 6

^*' the amount of Al is optimized.

Both tests lasted 1 hour and were started at room tempe¬ rature.

It is apparent from the above table that the catalyst according to the formula (2b) of the invention provides a better polymerization result than does the catalyst accor¬ ding to reference catalyst [ZrCp₂Cl₂] .

Example 18

Preparation of [Zr{N(R) C(Bu²)CHC(Ph)N(R) }C1₃] wherein R = Si(CH₃)₃ (trimethyl silyl) and the corresponding hafnium compound

The above Zr compound may be prepared by converting a compound according to formula (7) , wherein M' represents Li or K (D.S. Liu, D. Phil. Thesis, University of Sussex) , with an equimolecular amount of C₆H₅CN. This reaction may be carried out in diethyl ether (Et₂0) : [M{N(R)C(Bu')CHR}]₂ + ₂P CN

wherein Ph = C₆H₅

The product obtained is converted into Et₂0 with ZrCl₄, thus obtaining the desired compound.

Et_jO

[K{N(R)C(Ph)C(H)C(Bu^t)NR}]₂ + 2 ZrCI₄ 2[Zr{N(R)C(Bu^*)C(H)C(Ph)N(R)}Cg + 2KCI

Instead of this the desired compound may be obtained from [Zr{N(R)C(Bu^c)CHR}Cl₃] , prepared from ZrCl₄ + 1/2 [K{N(R)C(Bu^t)CHR}]₂ (D.S. Liu, D. Phil. Thesis, University of Sussex) and an equimolecular amount of C₆H₅CN.

The analogous hafnium compound was prepared according to a similar process.

Example 19

Preparation of [Zr{N(R) C(Ph)C(H)C(Bu^t)NR}Cl₃, wherein R is a trimethyl silyl group

Benzonitrile (0.35 cm³, 3.56 mmol) was slowly added to a solution of [K{N(R)C(Bu^t)CHR}]₂ (1.00 g, 3.56 mmol) in Et₂0 (ca. 30 cm³) at approx. 25°C. The yellow solution obtained was stirred for approx. 4 hours, followed by chilling to - 78°C and the addition of zirconium(IV) chloride (0.80 g, 3.43 mmol) . The mixture was slowly heated to approx. 25°C and stirred for another 12 hours. Volatile material was removed at 25°C/10^"2 torr. The residu was washed with hexane I S

(approx. 10 cm³) and then incorporated in CH₂C1-, by extrac¬ tion (approx. 40 cm³) . The concentrated filtrate from said extract provided yellow crystals of the title compound

(1.82 g, 94%) , melting point: >170°C (decomposition) (C 42.0; H 6.14; N 5.09. C₁₉H₃₃Cl₃N₂Zr requires C 42.0; H 6.14; N 5.16%) ; ^XH NMR (bij 360.1 MHz in CDC1₃) : δ -0.29 and 0.14

(SiMe₃, s, 9H) , 1.03 (Bu^ε, d, 9H) , 5.80 (CH, s, 1H) , 7.05

(phenyl, m, 4H) and 7.14 (phenyl, m, 1H) (abbreviations: s = singulet, d = doublet, m = ultiplet) .

The X-ray data of a single crystal of the title compound is included in table lc. The structure may be represented by formula (9c) .

Example 20

Preparation of [Hf{N(R) C(Ph)C(Bu^t)NR}Cl₃] wherein R = tri e- thyl silyl

Hafniu (IV) chloride (1.12 g, 3.52 mmol) was added to a solution of [Li{N(R)C(Ph)C(H)C(Bu )NR}]₂ (1.24 g, 1.76 mmol) in Et₂0 (approx. 25 cm³) at approx. -78°C while stirring took place. The mixture was slowly heated to approx. 25°C and stirred for another 12 hours. Volatile material was removed at 25°C/10^"2 torr. The residu was washed with hexane (approx. 10 cm³) and then incorporated in CH₂C1₂ by extrac¬ tion (approx. 40 cm³) . The concentrated filtrate from said extract provided pale yellow crystals of the title compound (1.36 g, 61%) (C 36.1; H 5.25; N 4.34%. C₁₉H₃₃Cl₃HfN₂ requires C 38.5; H 5.08; N, 4.28%) ; ^XH NMR (bij 360.1 MHz in CDC1₃) : δ 0.14 and 0.57 (SiMe₃, s, 9H) , 1.47 (Bu d, 9H) , 6.15 (CH, s, 1H) , 7.49 (phenyl, m, 4H) and 7.53 (phenyl, m, 1H) . Table 7 .

Intramolecular distances (A) and angles (°) ; estimated standard deviations are mentioned between brackets, a) Bonds

Zr-Cl (1) 2 .394 (2) Zr-Cl (2) 2 .449 (2)

Zr-Cl (3) 2 .406 (2) Zr-N(l) 2 .138 (5)

Zr-N(2) 2 .187 (5) Zr..C(l) 2 .602 (7)

Zr..C(2) 2 .535 (7) Zr..C(3) 2 .608 (7)

Si (1) - il) 1 .773 (6) Si (1) -C(14) 1 .847 (8)

Si(l) -C(15) 1 .856 (9) Si (1) -C(16) _i_ .852 (8)

Si (2) -N(2) 1 .795 (6) Si (2) -C(17) 1 .834 (8)

Si (2) -C(18) 1 .839 (10) Si (2) -C(19) 1 .853 (8)

N(l) -C(l) 1 .339 (10) N(2) -C(3) 1 .331 (9)

C(l) -C(2) 1 .409 (10) C(l) -C(4) .554 (10

C(2) -C(3) 1. .419 (10) C(3) -C(8) 1 .489 (10

C(4) -C(5) 1. .521 (12) C(4) -C(6) 1. .514 (10

C(4) -C(7) 1. .522 (10) C(8) -C(9) 1. .381 (9)

C(8) -C(13) 1. .399 (10) C(9) -C(10) 1. .390 (10

C(10) -C(ll) .379 (11) C(ll) -C(12) 1. .368 (10

C(12) -C(13) , .379 (11) b) Angles

Cl ) -Zr-Cl (2) 92 .15(7; Cl (1) -Zr-Cl (3) 101 • 51(71

Cl ) -Zr-N- (1) 131.8(2) Cl (1) -Zr-N(2) 101.6(2)

Cl ) -Zr-Cl (3) 91.76 (71 Cl (2) -Zr-N(l) 87.5(1)

Cl ) -Zr-N(2) 166..3 (2) Cl (3) -Zr-N(l) 126 • 7(2)

Cl ) -Zr-N(2) 85..5(2) N(l)-Zr-N(2) 83.4 (2)

N(l) -Si (1) -C(14) 108..7(3) N(l)-Si(l) -C(15) 116.3(4)

N(l) -Si(l) -C(16) 104..3(3) C(14) -Si (1) -C(15) 112.1(4)

C(14 ) -Si(l) -C(16) 107..8 (4) C(15) -Si (1) -C(16) 106.9(4)

N(2) -Si (2) -C(17) 111..1 (3) N(2) -Si (2) -C(18) 105.3(4)

N(2) -Si (2) -C(19) 111..7(3) C(17) -Si (2) -C(18) 107.7(4)

C(17) -Si(2) -C(19) 110..6 (4) C(18) -Si (2) -C(19) 110.3 (4)

Zr-N (l)-Si(l) 124..9(3) Zr-N(l)-C(l) 94 • 1(4)

Si (1) -N(l) -C(l) 140..5(5) Zr-N(2) -Si (2) 139.8(3)

Zr-N (2) -C(3) 92. 4) Si(2) -N(2) -C(3) 126 4 (5)

N(l) -C(l) -C(2) 117. 6) N(l) -C(l) -C(4) 122 6 (6)

C(2) -C(l I -C(4) 119. (7) C(l) -C(2) -C(3) 128 9 (7)

N 2) -C(3 I -C(2) 121. 6) N(2) -C(3) -C(8) 121 9 (6)

C 2) -C l -C(8) 116. (6) C(l) -C(4) -C(5) 112 5 (6)

C 1) -C l -C(6) 107. 6) C(l) -C(4) -C(7) 109 3 6)

C 5) -C ι -C(6) 108. 6) C(5) -C(4) -C(7) 107 8(6)

C 6) -C i -C(7) 111. 6) C(3) -C(8) -C(9) 120 9(6)

Cι 3) -C ' -C(13) 119. 6) C(9) -C(8) -C(13) 119 8(6)

Cι 8) -C -C(10) 119. 7) C(9) -C(10) -C(ll) 119 3(6)

Cι 10) -C(ll) -C(12) 121. 7) C(ll) -C(12) -C(13) 119 1(7)

Ci 8) -C(13) -C(12) 120 .3 6) Ethene and propene were polymerized by using two different catalysts, namely the above-prepared zirconium compound and a zirconium compound according to the formula (8c) descri¬ bed in Dutch Patent Application 9400919 (not pre-publis- hed) , which was filed on 7th June 1994, which catalysts are herein referred to as catalysts A and B respectively. The polymerization activity was tested at 40 bar and room temperature for ethene and at 1 bar and room temperature for propene. The results are indicated below.

Tests with ethene at high pressure (40 bar) : 100 ml tolue¬ ne, 5 ml of a 30% (wt. %) solution of MAO (methyl aluminium oxane; witco) in toluene acting as a co-catalyst and 5 ml of a 0.011 M solution of catalyst A or B in toluene were charged to an autoclave. The autoclave was closed, heated to 50°C and pressurized with ethene of 40 bar, while quick stirring took place. The pressure was maintained at a constant 40 bar during the test. Immediately after the addition of ethene the internal temperature of the reaction mixture rose (to 115°C for B and to 85°C for A) . After 1 hour the temperature had sunk to 70°C (for A as well as for B) and the monomer was discharged. In order to terminate the reaction a solution of 10% concentrated HCl (aqueous) in methanol was added to the reaction mixture. The polymer was collected and washed with HCl/methanol, water and methanol. After 16 drying for 16 hours at 50°C the yield (in g) was determined.

Tests with propene at low pressure (1 bar) : 20 ml toluene (distilled with Na) , 5 ml of a 30% (wt. %) solution of MAO in toluene and 5 ml of a 0.011 M solution of compound A or B in toluene were successively charged to a three-neck flask. The reaction mixture was stirred for 5 minutes at room temperature and then degased at a reduced pressure. Propene was added from a buffer vessel containing 21 of propene of 1 bar (1500 mol/mol A or B) , while quick stir¬ ring took place. The pressure reduction was monitored by means of a mercury manometer. The polymerization process was terminated by the addition of a solution of 10% concen¬ trated HCl (aqueous) in methanol. The polymer was collected and washed with HCl/methanol, water and methanol. After drying for 16 hours at 50°C the yield (in g) was determi¬ ned.

Catalyst monomer P (bar) T (°C) time yield TOΝ^a (hours!ι (cr) (mol/mol)

B ethene 40 50-115 1 16.7 10.8.10³

A ethene 40 50-85 1 25.0 16.2,10³

B propene 1 20 2 C.79 340

A propene 1 20 0.5 0.38 165

Claims

1. Compounds according to formula (1) of the formula sheet, wherein M signifies Zr, Ti or Hf, R_: repre- 5 sents a ligand, X signifies an atom or group that can be readily isolated, and n = 2 or 3.

2 Compounds according to claim 1, wherein R in the ligand R_x represents an alkylene group, an o-arylene 10 group, or an aryl group, which may be substituted, R, (formula la) or R' (formula lb) represent a phenyl group, a t. butyl group or a . pentyl group, and Q signifies -N-Si(CH₃)₃ or -C(H) -Si (CH,) ,.

15 3. Compounds according to claim 1 of 2, wherein M sig¬ nifies Zr, R represents a phenyl group or a naphtalene group, both of which groups may be sub¬ stituted, R, represents a t. butyl group, X is a halogen atom and Q signifies -N-Si(CH₃)₃.

20

4. Compounds according to formula 2a of the formula sheet, wherein Bu^c is a t . butyl group and R repre¬ sents a phenyl group or a naphtalene group, both of which groups may be substituted.

25

5. Compounds according to formula 3a of the formula sheet, wherein Bu^: represents a t. butyl group and R₂ may be a hydrogen atom or another substituent.

30 6. Compounds according to claim 5, wherein R₂ represents a hydrogen atom or a p-methyl group.

7. Compounds according to formula 4a, wherein B^c repre¬ sents a t. butyl group.

35.

Compounds according to formula 5a of the formula sheet, wherein the novel intermediate products have the structure according to formula 5a of the formula sheet, wherein the significance of R, R, and Q is as indicated before and wherein Y represents an alkali metal, preferably potassium.

9. Compounds according to claim I, wherein: Q represents -N-Si (CH₃) ₃;

R represents a ethylene group or an o-phenylene group, which may or may not be substituted; R' represents a -butyl group;

M represents Zr; A represents a halogen atom.

10. Compounds according to formula (2b) , wherein Bu^c represents a tertiary butyl group.

11. Compounds according to formula (lc) of the formula sheet, wherein:

R¹ and R⁵ are identical or different from each other and each of said symbols represents a group

C (C.- , alkyl) ₃ or Si (C₁-C₄ alkyl) ₃, wherein each of the alkyl groups may be substituted by one or more phenyl groups, or a group C-C₆H₅(C₁-C₄ alkyl) ₂, a group C(C₆H₅)₂ ( _L-C_J alkyl) or a group C(C₆H₅)₃, whe- rein C₆H₅ is a phenyl group;

R² represents a tertiary alkyl group, with the terti¬ ary carbon atom bonded to the diketiminato system; R³ represents a hydrogen atom or a C₁-C₃ alkyl group; and R⁴ represents a phenyl group or phenyl group substi¬ tuted by one or more C,-C₄ alkyl groups.

12. A compound according to claim 11, wherein R¹ and R₅ are Si(CH₃), or C(CH₃)₃; R² is C ( CH₃ ) ₃ or C ( CH₃ ) ₂C₂H₅ ; r > 3 is a hydrogen atom;

R⁴ is C₆H₅ or C₆H₅CH₃ -4 ; and A is halogen .

13. A compound according to claim 12, wherein R¹ and R₅ are both Si (CH₃) ₃; R² is C(CH₃)₃;

R³ is hydrogen ; R⁴ is C₆H_S ; M is Zr ; and A is Cl .

14. A method for polymerizing unsaturated hydrocarbons, characterized in that the catalyst used is the com¬ pound according to any one of the claims 1 - 13.

15. A method according to claim 14, characterized in that also a co-catalyst is used.

16. A method according to claim 15, characterized in that said co-catalyst is methyl aluminium oxane.

17. A method according to any one of the claims 14 - 16, characterized in that said unsaturated hydrocarbon is ethene or propene .

18. Catalyst-preparations, wherein one or more of the compounds according to claims 1 - 17 are contained in said preparations as active constituents, toge¬ ther with a carrier material .

19. A method for the preparation of the compound having the formula (2b) , wherein Li₂ (tetramethyl ethylenedi- amine) ₂{l.2-C₆H₄ (CHSi (CH₃) ₃) ₂} is converted with Bu^ECN, forming Li₂ (tetramethyl ethylenediamine)₂{l.2- C₆H₄ (CHCBu^cNSi (CH₃) ₃) ₂} , wherein the latter compound is converted with potassium t.butylaat, forming K₂ (tetramethyl ethylenediamine) {1.2-C₆H₄ (CHC- Bu^cNSi (CH₃) ₃) ₂} and wherein the compound obtained is converted with ZrCi₄, forming the compound having the formula (2b) .

20. A method for preparing a compound having the formula (lc) , wherein: a) a compound (5c) of the formula sheet, wherein M' represents Li or K and wherein the signifi¬ cance of R¹, R², R³ and R⁵ is as indicated in claim 10, is converted with a phenylcyanide, and wherein the reaction product obtained is converted with MA₄, wherein the significance of A and M is as indicated in claim 10; or b) a compound according to the formula (5c) of the formula sheet is converted with MA₄, and the complex obtained is converted with a phenyl cyanide.

21. A method according to claim 20, wherein: a) a compound according to the formula (7c) , whe- rein M' is Li or K and R is a trimethyl silyl group, is converted phenyl cyanide, and the reaction product obtained is ZrX₄ or HfX₄, whe¬ rein X is a halogen, preferably chlorine; or b) a compound according to formula (7c) , wherein the significance of M' and R is as indicated above under a) , is converted with ZrX₄ or HfX₄, wherein X is a halogen, preferably chlorine, and the complex obtained is converted with phenyl cyanide.