KR20000016125A - Metallocenes and catalysts for polymerization of olefins - Google Patents

Abstract

PURPOSE: A polymerizing method for an olefin is provided to be formed by polymer-reacting more than 1 olefin monomer in the presence of a catalyst system. CONSTITUTION: It is disclosed a new class of bridged metallocene compounds of formula (I) wherein R1 and R2 can be hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radicals; R3 and R4 form a condensed, 5- to 8-membered, aliphatic, aromatic or heterocyclic ring; M is a transition metal of groups 3, 4, 5, lanthanide or actinide; X is hydrogen, halogen, -R, -OR, -OSO2CF3, -OCOR, -SR, -NR2 or PR2, wherein R is a hydrocarbon substituent; and p is 0-3. Furthermore, a catalyst system for olefin polymerization based on the above bridged metallocene compounds and the ligands for their preparation are disclosed.

Description

Catalysts for Metallocene and Olefin Polymerization

Metallocene compounds are known as catalyst components for olefin polymerization with two cyclopentadienyl groups bridged.

For example, European patent application EP 0 129 368 discloses a catalyst system for the polymerization of olefins containing a coordination complex of a potential metal and bis-cyclopentadienyl, wherein the two cyclopentadienyl groups are bridging groups. can be linked by a group). In this kind of metallocene compound, two cyclopentadienyl groups are generally divalent groups having two or more carbon atoms, such as ethylene groups, or divalent groups having elements other than carbon atoms, such as dimethyl-silanediyl groups ( dimethyl-silanediyl group).

Metallocene compounds having two cyclopentadienyl groups bridged by a single carbon atom are also known. In particular, it is known to have two different two cyclopentadienyl groups as this type of metallocene compound.

For example, European patent application EP 0 351 392 can be used for the production of syndiotactic polyolefins and describes a catalyst containing a metallocene compound having two cyclopentadienyl groups connected by a bridge between the two. In this case, one of the two cyclopentadienyl groups is substituted in a form different from the other. Compounds exemplified as being preferred are isopropylidene (fluorenyl) (cyclopentadienyl) hafnium dichloride.

For metallocene compounds having two identically substituted cyclopentadienyl groups bridged by a single carbon atom, European patent application EP 0 416 566 discloses alumoxane and two cycles which are the same or different from one another. The pentadienyl ring is a divalent group -CR ₂ -wherein R is broadly defined, preferably an alkyl or aryl group, in the presence of a catalyst consisting of a metallocene compound bridged by a liquid phase It describes a process for the polymerization of α-olefins carried out in monomers. Two compounds exemplified as being preferred are Ph ₂ C-bis (indenyl) -ZrCl ₂ and (CH ₃ ) ₂ C-bis (indenyl) -ZrCl ₂ , with only the latter compound being substantially effective in the present application. Was used in the polymerization of propylene to produce low molecular weight polypropylene waxes.

International application WO 96/22995 discloses a class of metallocene compounds having two identically substituted cyclopentadienyl groups bridged by -CR ₂ -divalent groups. The definition given for substituent R does not include the case where both R are hydrogen. When propylene is polymerized in the presence of the catalyst based on the metallocene, isotactic polypropylene having a high molecular weight and a high degree of regularity is obtained. However, the molecular weights that can be obtained at industrially useful polymerization temperatures are still too low for various applications, for example by extrusion of thick articles such as pipes.

Therefore, it is desirable to improve the class of single-carbon-bridged metallocenes by providing novel compounds that can extend the range of molecular weights obtainable in the use of catalysts for the polymerization of olefins.

J.A. Ewen et al. (Macromol. Chem .; Macromol. Symp. 48/49, 253-295, 1991) for evaluating the relationship between structure and stereospecificity, particularly in their isotacticity in propylene polymerization. A series of group IV metallocenes with chiral ligand environments was described. Among the metallocenes used here are methylene-bis (indenyl) hafnium dichloride, which provides polypropylene with low isotacticity.

European patent application EP 0 751 143 discloses carbon-bridged by reacting at least one cyclopentadienyl compound with a carbonyl compound in the presence of a base and a phase-transfer catalyst in two or more phase systems. A method for preparing a bis-cyclopentadienyl compound is described. Methylene-bis (4-phenyl-1-indenyl) zirconium dichloride, methylene-bis (4-isopropyl-1-indenyl) zirconium dichloride in a number of bridged metallocenes obtainable by the process And methylene-bis (4,5-benzo-1-indenyl) zirconium dichloride are mentioned as examples of description; There is no report on these uses in their synthesis or olefin polymerization.

Summary of the Invention

Applicants have recently discovered a novel class of metallocenes which surprisingly have two identical cyclopentadienyl groups linked to one another by methylene groups; The metallocene can be advantageously used as a catalyst composition for the polymerization of olefins.

Therefore, according to the first aspect, the present invention provides a bridged metallocene compound having the formula (I)

[Wherein, R ¹ and R ² are the same as or different from each other, a hydrogen atom, a linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ ~C ₂₀ is a group selected from alkyl, aryl and C ₇ ~C ₂₀ aryl group consisting of an alkyl group, which may include Si or Ge atoms;

Substituents R ³ and R ⁴ are condensed, 5- to 8-membered, aliphatic, aromatic or heterocycle rings, optionally substituted, provided that R ¹ and R ² are hydrogen atoms and the condensed ring is benzene In the case of a ring, benzene is substituted at the ortho or meta position relative to the carbon atom of the cyclopentadienyl group linked to R ⁴ ;

M is a transition metal belonging to 3, 4 or 5 in the periodic table of elements (new IUPAC notation) or to the lanthanide or actinide group;

The groups X are the same or different from each other and are a single anionic sigma ligand selected from the group consisting of hydrogen, halogen, -R, -OR, -OSO ₂ CF ₃ , OCOR, -SR, -NR ₂ and PR ₂ groups, where R is C _{1 to} C ₂₀ alkyl, C _{3 to} C ₂₀ cycloalkyl, C _{2 to} C ₂₀ alkenyl, C _{6 to} C ₂₀ aryl, C _{7 to} C ₂₀ alkylaryl and C _{7 to} C ₂₀ arylalkyl groups, which are Si or Ge May contain atoms; And

p is an integer of 0 to 3 and is equal to the value of 2 minus the oxidation state of the metal M.

Another object of the present invention is to provide ligands of formula (II) and their double-bond isomers, except bis (3-t-butyl-indenyl) methane, wherein the ligands are the bridged metals of formula (I) Useful for the preparation of sen compounds:

[Wherein R ¹ , R ² , R ³ and R ⁴ have the meanings reported above]

Furthermore, the present invention provides a process for preparing the metallocene compound of formula (I), as well as contacting (A) at least one bridged metallocene compound of formula (I), and (B) a suitable activating cocatalyst. It relates to a catalyst system for olipine polymerization, containing the product obtained.

Finally, the present invention provides a process for the polymerization of olefins consisting of polymerizing one or more olefinic monomers in the presence of the aforementioned catalyst system.

The present invention relates to a new class of bridged metallocene compounds, to their preparation and to catalysts for the polymerization of olefins containing them. The invention also relates to a novel class of ligands useful as intermediates for the synthesis of the metallocenes.

According to the invention, the characteristics and advantages of the bridged metallocene compounds of formula (I), methods for their preparation, catalyst systems containing them, their use in olefin polymerization and ligands of formula (II) are further described in the detailed description below. Explain in detail.

In the bridged metallocene compound of formula 1 according to the invention, the substituents R ³ and R ⁴ preferably form a condensed benzene ring which may be substituted; The transition metal M is preferably Ti, Zr or Hf; Substituent X is preferably chlorine or methyl; p is preferably 2.

Particularly interesting subclasses of the bridged metallocene compounds in the present invention (subclass (a)) are compounds of formula I wherein the substituents R ³ and R ⁴ form a condensed benzene ring substituted at the position 3 In more detail the compound is a bridged bis-indenyl compound of Formula III:

[Wherein R ² is not hydrogen, R ¹ , R ² , M, X and p have the meanings reported above;

Substituents R ⁵ are the same or different from each other and are linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl and C _7- Selected from the group consisting of C ₂₀ arylalkyl groups, which may include Si or Ge atoms, or the substituent R ⁵ in two vicinal positions, forms a 5 to 8, preferably 6 membered ring; n is an integer of 0 to 4]

Suitable examples of compounds of formula III belonging to subclass (a) are as follows:

Methylene-bis (3-methyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-ethyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-isopropyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-dimethylsilyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-diethylsilyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-phenyl-1-indenyl) zirconium dichloride or dimethyl, and

Methylene-bis (3-phenyl-4,6-dimethyl-1-indenyl) zirconium dichloride or dimethyl.

Particularly interesting metallocene compounds of formula III are those in which R ² is three linear or branched, saturated or unsaturated C ₁ -C ₁₀ alkyl, C ₅ -C ₁₂ cycloalkyl, C ₆ -C ₁₂ aryl, C _7- C ₁₂ alkylaryl and C ₇ ~C is a C, Si or Ge atom is substituted by ₁₂ arylalkyl ^{group, R 1, R 5, M} , X, n and p is a compound having the meaning reported above. Suitable substituents of this kind R ² are tert-butyl, trimethylsilyl, trimethylsilyl, trimethylgeryl, 2,2-dimethyl-propyl and 2-methyl-2-phenyl-ethyl groups, of which tert-butyl is particularly preferred Do. Examples of bridged metallocene compounds belonging to the particularly preferred subclass (a) are as follows:

Methylene-bis (3-t-butyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-trimethylsilyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-trimethylgeryl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-3-t-butyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-3-trimethylsilyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-3-trimethylgeryl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3-t-butyl-5,6-dimethyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3,5-di-t-butyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (3,6-di-t-butyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis [3- (2,2-dimethyl-propyl) -1-indenyl] zirconium dichloride or dimethyl, and

Methylene-bis [3- (2-methyl-2-phenyl-ethyl) -1-indenyl] zirconium dichloride or dimethyl.

Particularly preferred metallocenes are rac-methylene-bis (3-t-butyl-indenyl) zirconium dichloride.

An advantageous property for this particular class of metallocenes of formula III with bulky R ² substituents is that the isomers, when present in the meso isomeric form, are generally not active in the polymerization of olefins and need to be separated from the racemic form. It is not. Furthermore, the metallocenes have surprisingly advantageous results in the polymerization of propylene as described below.

Another useful subclass of the bridged metallocene compounds in the present invention (subclass (b)) is represented by the aforementioned bis-indenyl metallocene compounds of formula III, wherein R ² is hydrogen And R ¹ , R ⁵ , M, X, p and n have the meanings reported above. Suitable examples of metallocene compounds belonging to subclass (b) are as follows:

Methylene-bis (2-methyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-ethyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-4-phenyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-ethyl-4-phenyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis [2-ethyl-4- (1-naphthyl) -1-indenyl] zirconium dichloride or dimethyl,

Methylene-bis (2,5,6-trimethyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (6-t-butyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis [2-methyl-4- (1-naphthyl) -1-indenyl] zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-acenaphthyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-ethyl-acenaphthyl-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-methyl-4,5-benzo-1-indenyl) zirconium dichloride or dimethyl,

Methylene-bis (2-ethyl-4,5-benzo-1-indenyl) zirconium dichloride or dimethyl.

A particularly preferred subclass (b) is characterized in that R ² is hydrogen and the R ⁵ groups at positions 4 and 7 of the indenyl residue are not hydrogen. Examples of R ⁵ groups at the 4 and 7 positions of indenyl are methyl, ethyl or phenyl groups. Suitable examples of such metallocene compounds are methylene-bis (2,4,7-trimethyl-1-indenyl) zirconium dichloride or dimethyl, methylene-bis (4,7-dimethyl-1-indenyl) zirconium dichloride Or dimethyl.

A further object of the present invention is a method for manufacturing a metallocene compound bridging the metal of formula Ⅰ which service of formula Ⅳ - described in the formula MX _{p + 2} (equation a cyclopentadienyl ligand, M, X and P are as defined above And the same).

[Wherein R ¹ , R ² , R ³ and R ⁴ have the meanings reported above and A is a suitable leaving group]

The two double bonds in each of the cyclopentadienyl rings of the ligand of formula IV may be at any acceptable position. Leaving group A is a cation of an alkali metal or alkaline earth metal or -SiR ₃ , or -SnR ₃ , wherein R is C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₂ -C ₂₀ alkenyl, C _6- C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl and C ₇ -C ₂₀ arylalkyl group.

If at least X group 1 of the bridged metallocene compound (I) is not halogen, at least one halogen of the metallocene dihalide obtained as described above should be replaced with at least a non-halogen substituent X 1. . The substitution reaction can be carried out by standard procedures, for example, if X is an alkyl group, the metallocene dihalide is reacted with an alkylmagnesium halide (Grignard reagent) or an alkyl lithium compound.

Due to the special bridging groups of the metallocenes of the invention, α-substituents, i.e., C ₁ -C ₁₀ alkyl, C ₅ -C, wherein two or three linear or branched, saturated or unsaturated, R ¹ and / or R ⁴ are _A bulky group, such as a trimethyl-silyl group, such as a C, Si or Ge atom substituted with ₁₂ cycloalkyl, C ₆ -C ₁₂ aryl, C ₇ -C ₁₂ alkylaryl and C ₇ -C ₁₂ arylalkyl group The spatial arrangement of the metallocene compound of I does not allow meso isomers. This is a great advantage of the bridged metallocene compounds of the invention, whereby the compounds of the invention are obtainable directly as pure racemic forms and do not require a difficult and cumbersome process to remove meso isomeric forms.

Another object of the present invention is the ligands corresponding to formula (II) and their double bond isomers, except bis (3-t-butyl-indenyl) methane.

[Formula II]

[Wherein R ¹ , R ² , R ³ and R ⁴ have the meanings reported above]

In fact, bis (3-t-butyl-indenyl) methane is mentioned among a number of metallocene ligands of USP 5,459,117. The patent refers to a broad class of metallocene compounds containing various substituted cyclopentadienyl rings, wherein the substituents are C _s , C ₂ , pseudo-C _s or pseudo to the ligand. ) -C ₂ Gives symmetry.

Ligands of formula (II) can be prepared in several ways. Particularly suitable methods are the European patent application No. 97200933.6. This method makes it possible to prepare compounds which have been hardly obtained by methods known to the art so far, for example compounds having bulky substituents R ¹ .

The metallocene compound of the present invention can be conveniently used as a catalyst component for olefin polymerization. Thus, according to a further aspect, the present invention provides a catalyst system for olefin polymerization containing a product obtainable by contacting:

(A) at least one bridged metallocene compound of formula (I) or (III) above, and

(B) appropriate activation cocatalyst

The activated cocatalyst is preferably a compound capable of forming alumoxane and / or alkylmetallocene cations.

In the catalyst system of the present invention, both the bridged metallocene compound and the alumoxane are represented by the formula AlR ⁶ ₃ or Al ₂ R ⁶ ₆ , wherein the substituents R ⁶ are the same as or different from each other, and hydrogen, halogen, linear Or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl and C ₇ -C ₂₀ arylalkyl groups May have a Si or Ge atom].

Non-limiting examples of the organometallic aluminum compound of formula AlR ⁶ ₃ or Al ₂ R ⁶ ₆ are as follows:

Al (Me) ₃ , Al (Et) ₃ , AlH (Et) ₂ , Al (iBU) ₃ , AlH (iBU) ₂ , Al (iHex) ₃ , Al (iOCt) ₃ , Al (C ₆ H ₅ ) ₃ , Al (CH ₂ C ₆ H ₅ ) ₃ , Al (CH ₂ CMe ₃ ) ₃ , Al (CH ₂ SiMe ₃ ) ₃ , Al (Me) ₂ iBu, Al (Me) ₂ Et, AlMe (Et) ₂ , AlMe (iBU) ₂ , Al (Me) ₂ iBu, Al (Me) ₂ Cl, Al (Et) ₂ Cl, AlEtCl ₂ and A1 ₂ (Et) ₃ Cl ₃ , wherein Me = methyl, Et = ethyl , iBu = isobutyl, ihex = isohexyl, iOct = 2,4,4-trimethyl-pentyl.

Among the organometallic aluminum compounds, trimethyl aluminum (TMA), triisobutyl aluminum (TIBAL) and tris (2,4,4-trimethyl-pentyl) aluminum (TIOA) are preferable.

When the activating cocatalyst (B) of the catalyst system is alum oxane, it is a linear, branched or cyclic compound containing at least one group of the form:

[Wherein R ⁷ is the same or different and is hydrogen, linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl And a C _{7 to} C ₂₀ arylalkyl group, which may have Si or Ge atoms, or R ⁷ is —O—Al (R ⁷ ) ₂ ];

In particular, linear alum oxane has the formula:

Wherein m is an integer from 0 to 40 and R ⁷ has the same meaning as above; and the cyclic alum oxane has the formula:

[Wherein m is an integer from 2 to 40 and R ⁷ has the same meaning as above]

Among the linear and cyclic alumoxanes mentioned above, R ⁷ is preferably methyl, ethyl, isobutyl or 2,4,4-trimethyl-pentyl.

Examples of alumoxanes suitable as activating cocatalysts in the catalyst system in the present invention include methylalumoxane (MAO), isobutylalumoxane (TIBAO) and 2,4,4-trimethyl-pentylaloxane (TIOAO) and 2-methyl -Pentylalumoxane. Mixtures of different alumoxanes can also be used.

In addition, the activating cocatalyst as component (B) in the catalyst of the present invention is a reaction product between water and the organometallic aluminum compound, preferably of the formula AlR ⁶ ₃ or Al ₂ R ⁶ ₆ , wherein R ⁶ is Has meaning]. Particularly suitable examples include the organometallic aluminum compounds described in EP 0 575 875 (formula (II)) and those described in WO 96/02580 (formula (II)). Non-limiting examples of organometallic aluminum compounds of the formula AlR ⁶ ₃ or Al ₂ R ⁶ ₆ are as follows:

Tris (methyl) aluminum, tris (isobutyl) aluminum, tris (isooctyl) aluminum, bis (isobutyl) aluminum hydride, methyl-bis (isobutyl) aluminum, dimethyl (isobutyl) aluminum, tris (isohexyl) Aluminum, tris (benzyl) aluminum, tris (tolyl) aluminum, tris (2,4,4-trimethyl-pentyl) aluminum, bis (2,4,4-trimethyl-pentyl) aluminum hydride, isobutyl-bis (2 -Phenyl-propyl) aluminum, diisobutyl- (2-phenyl-propyl) aluminum, isobutyl-bis (2,4,4-trimethyl-pentyl) aluminum and diisobutyl (2,4,4-trimethyl-pentyl Aluminum.

Particularly preferred aluminum compounds are tris (2,4,4-trimethylpentyl) aluminum (TIOA) and trisisobutylaluminum (TIBA).

Mixtures of different organometallic aluminum compounds and / or alumoxanes may also be used.

The molar ratio between aluminum and metal M of the bridged metallocene compound is preferably comprised between 10: 1 and 50,000: 1, more preferably between 100: 1 and 4,000: 1.

The activating cocatalyst (B) of the catalyst system of the present invention is a compound capable of forming an alkylmetallocene cation; Preferably, the compound has the formula Y ⁺ Z ^- wherein Y ⁺ is Bronsted acid capable of giving protons and irreversibly reacting with the substituent X of the metallocene compound having the formula (I), Z ^- is a compatible non-coordinating (non-cordinatting) anion, which is capable of stabilizing the two compounds derived from the reaction is likely to be of sufficiently replaced by a reactive olefin-based active catalyst species. Preferably, Z ⁻ contains one or more boron atoms. More preferably, the anion Z ⁻ is of the formula BAr ₄ ⁽⁻⁾ wherein the same or different substituents Ar is an aryl group such as phenyl, pentafluorophenyl or bis (trifluoromethyl) phenyl. Tetrakis-pentafluorophenyl borate is particularly preferred. Furthermore, compounds of formula BAr ₃ may be usefully used.

The catalyst of the present invention can be used on an inert support. This may include a bridged metallocene compound (A), or a reaction product of compound (A) with compound (B), or compound (B) followed by metallocene compound (A), with a suitable inert support such as By depositing on silica, alumina, magnesium halide, styrene / divinylbenzene copolymer, polyethylene or polypropylene.

Suitable inert supports consist of porous organic supports functionalized with groups with active hydrogen atoms; Particularly preferred organic supports are the partially crosslinked styrene polymers described in European patent application EP 0 633 272.

Another class of inert supports particularly suitable for the catalyst system according to the invention comprises olefinic porous prepolymers, in particular propylene porous prepolymers described in international patent application WO 95/26369.

A more suitable class for use according to the invention includes the porous magnesium halide support described in international patent application WO 95/32995.

Supported catalyst systems may be usefully employed in the gas phase polymerization process, optionally in the presence of alkylaluminum compounds.

Another advantage of the bridged metallocene compounds of the invention, especially those with bulky substituents such as tert-butyl groups, is that they can be dissolved in aliphatic hydrocarbons such as pentane, isobutane, butane and propane. This property facilitates more intimate contact of the support with the metallocene, especially when the support is a porous material, thus achieving more uniform and stable fixation of the metallocene on the support.

Another object of the present invention is a process for the polymerization of olefins, which consists in the polymerization of one or more olefin monomers in the presence of the above-mentioned catalyst system. The catalyst according to the invention is for example a homopolymerization of ethylene or α-olefins such as propylene and 1-butene; Copolymerization of ethylene with α-olefins such as propylene, 1-butene and 1-hexene; Copolymerization of propylene with ethylene or propylene with a C ₄ to C ₁₀ α-olefin such as 1-butene; It can be conveniently used in the homopolymerization of cyclic olefins or copolymerization thereof with ethylene.

Particularly interesting results are obtained when the catalyst of the invention is used for the polymerization of propylene. According to a particular embodiment of the olefin polymerization process of the present invention, propylene is polymerized in the presence of racemic isomers of the bridged metallocene compound of formula III subclass (a) as mentioned above. In fact, polymerization of propylene in the presence of the metallocene has a high molecular weight, a narrow molecular weight distribution, a high isotacticity (typically a mmmmm pentad content of 90% or more) at an industrially advantageous temperature (ie, 50 ° C. or more), Propylene, which also has a high level of regioregularity, can be produced in high yield. The ¹³ C-NMR analysis performed on the propylene polymer obtained with the bridged metallocene compound belonging to subclass (a) shows no structural units due to Regio irregular insertion (RI). Regarding the above analysis method, reference may be made to "Macromolecules, 1995, vol. 28, page 6667-6676".

The resulting propylene polymer has a small fraction of soluble in xylenes, which is generally less than 5% by weight, preferably less than 3% by weight, more preferably less than 1% by weight. In addition, the polymers are usually free of acetone-soluble fractions (atatic propylene oligomers).

According to another specific embodiment of the process in the present invention, at least one olefin oligomerizes in the presence of racemic isomers of the bridged metallocene compound of subclass (b) of the above-mentioned formula (III). In practice, by polymerizing at least one olefin, in particular propylene, in the presence of said specific metallocene. Low molecular weight propylene wax is obtained with isotacticity significantly higher.

Especially advantageous are the bridged metallocene compounds (III) belonging to the subclass (b), wherein R ² is a hydrogen atom and R ^{5, which} is a substituent at the 4 and 7 positions of the indenyl group, is not a hydrogen atom. Preferably, R ¹ is a hydrogen atom. A particularly preferred metallocene compound is rac-methylene-bis (4,7-dimethyl-1-indenyl) zirconium dichloride, which is very useful for oligomerization of propylene.

When the polymerization of propylene is carried out in the presence of rac-methylene-bis (4,7-dimethyl-1-indenyl) zirconium dichloride, the molecular weight of the propylene wax obtained is rac-methylene known in the art under the same conditions. Than the molecular weights of the waxes obtained using bis (1-indenyl) zirconium dichloride or the corresponding ethylene-bridged analogous compound (ie rac-ethylene-bis (1-indenyl) zirconium dichloride) Lower than expected

Another class of useful bridged metallocene compounds (III) belongs to the subclass (b), wherein R ¹ is not hydrogen, R ² is hydrogen and n is 0. Even such substituted patterns provide very low molecular weight propylene waxes.

Thus, a further advantage of the present invention is evident that the bridged metallocene compounds according to the invention allow to obtain polymers having a very wide range of molecular weights. In particular, the compounds of the present invention further increase the molecular weight if a high molecular weight polymer is required (by using a bridged metallocene compound belonging to subclass (a)) and the target is a low molecular weight polymer. It is possible to further reduce the molecular weight (by using bridged metallocene compounds belonging to subclass (b)).

Another advantage of the properties of the metallocenes of the present invention is that the use of a small amount of hydrogen leads to a significant increase in the polymerization activity without substantially affecting the molecular weight of the obtained polymer.

The process for the polymerization of olefins according to the invention can be carried out in the liquid phase, optionally in the presence of an inert hydrocarbon solvent, or in the gas phase. The hydrocarbon solvent may be aromatic such as toluene or aliphatic such as propane, hexane, heptane, isobutane or cyclohexane.

The polymerization temperature is usually -100 ° C to + 100 ° C, preferably 0 ° C to + 80 ° C. The lower the polymerization temperature, the higher the resulting molecular weight of the obtained polymer.

The molecular weight of the polymer can be changed by varying the type or concentration of the catalyst component or by using a molecular weight regulator such as hydrogen.

The molecular weight distribution can be altered by using a mixture of different metallocene compounds or by carrying out a multistage polymerization with different polymerization temperatures and / or concentrations of molecular weight regulators.

Polymerization yield depends on the purity of the metallocene compound of the catalyst. The metallocene compound obtained by the method of the present invention may be used as it is or may be subjected to purification treatment.

The catalyst components can be contacted before the polymerization step. The pre-contact concentrations for metallocene component (A) to the metal is usually from 1 to 10 ^-8 mol / ℓ, preferably 10 to 10 ^-8 mol / ℓ when the component (B). The preliminary contact is usually carried out in the presence of a hydrocarbon solvent, suitably in the presence of a small amount of monomer. In the preliminary contact, an unpolymerizable olefin such as 2-butene, neohexene, or the like can be used.

The following examples are illustrative only and are not intended to be limiting.

General process and characteristic description

The following abbreviations were used:

THF = tetrahydrofuran, Et ₂ O = diethyl ether, NaOEt = sodium ethoxide, ^t BuOK = potassium tert-butoxide, DMSO = dimethyl sulfoxide, BuLi = butyl lithium, DMF = N, N-dimethylformamide

All manipulations were performed under nitrogen using conventional Schlenk-line methods. The solvent was purified by degassing with (degassing) in N ₂ through the active Al ₂ O ₃ (8 sigan, N ₂ purge, 300 ℃) and stored under nitrogen. MeLi and BuLi (Aldrich) were used as such.

For ¹ H NMR all compound 200.13 MHz, ¹³ C NMR, if the referenced against the peak of residual CHCl ₃ in ¹ H NMR (7.25ppm on a Bruker AC 200 spectrometer operated by 50.323 MHz CDCl _3, residual CHDCl at 5.35ppm reference was analyzed by CD ₂ Cl ₂₎ or ^{13 C NMR (Broad Band decoupling mode} ) ( see against the peak of residual CHCl ₃ in CDCl _3, 77.00ppm hereinafter) with respect to the _second peak. All NMR solvents were dried over LiALH ₄ or CaH ₂ and distilled before use. Sample preparation was carried out under nitrogen using standard inert atmosphere methods. Some zirconocenes had low solubility so the samples were prepared as saturated solutions in 0.5 mL of solvent in a 5 mm NMR tube.

GC-MS analysis used HP MS Engine 5989 B device

The polymers were characterized as follows.

¹ H NMR and ¹³ C NMR analyzes were performed on a Bruker 400 MHz device. Samples were analyzed at 130 ° C. as a solution in tetrachlorodidutroethane. Assuming one double bond per chain, the Mn value was obtained from ¹ H NMR by measuring the ratio between total signal and olefin end group signal.

Intrinsic viscosity (I.V.) was measured at 135 ° C. in THN (for polyethylene) or tetralin (for polypropylene).

Melting point (Tm) was determined by Perkin Elmer Co. Was measured by differential scanning calorimetry (D.S.C.) on a DSC-7 device from Ltd .:

About 10 mg of the sample obtained from the polymerization is cooled to -25 ° C and then heated to 200 ° C to measure the scanning rate at 10 ° C / min. The sample was held at 200 ° C. for 5 minutes and then the scanning rate was cooled to 10 ° C./min. Secondary scanning was then performed in the same fashion as the first. The reported values were those obtained in the first scanning.

Molecular weight distribution was determined by GPC performed in orthodichlorobenzene at 135 ° C. on a WATERS 150 instrument.

Synthesis of Metallocenes

Collage 1

rac-methylene-bis (3-t-butyl-1-indenyl) zirconium dichloride

(a) Synthesis of 3-t-butyl-1-indene

15.8 dissolved in 42.0 g of indene (industrial grade, 94% GC, 39.5 g, 340 mmol), 50% by weight aqueous KOH (308 g in 308 mL) and 139.7 g tert-butylbromide (1019.6 mmol) g of adogen (Adogen, Aldrich, 34 mmol) was introduced in this order into a 1 L jacketed glass reactor with a mechanical stirrer (Buchi) at room temperature. The organic phase turns green. The mixture was heated to 60 ° C., maintained for 2 hours under vigorous stirring (build-up of pressure was observed up to 2.5 bar-g) and then cooled to room temperature. Total reaction time was 3 hours. The organic phase was extracted with industrial hexane (3 × 20 mL) and analyzed by GC showed conversion of 74.5 wt.% 3-tert-butyl-indene and 1.8 wt.% 1-tert-butyl-indene. 13.7 weight percent. The solution was evaporated under reduced pressure (rotovac) and the resulting dark brown viscous liquid was distilled at 1 mmHg to collect the boiled fractions at 70-80 ° C. (40 g, 76.8% 3-tert-butyl-indene and 19.5% 1-tert-butyl-indene, no indene).

(b) Synthesis of Bis (1-t-butyl-3-indenyl) methane

Into a three-necked 1 L flask with a stir bar were introduced in this order: 10.32 g of ^t BUOK (92 mmol), 400 mL of DMF, 80.6 g of tert-butyl-indene obtained above (98.2% GC). 460 mmol) and 18.6 mL of aqueous formalin (37%, 6.9 g, 230 mmol); (The reaction was added dropwise for 15 minutes). A slightly exothermic reaction was observed and the solution turned red. The mixture is stirred at room temperature for 2 hours; The mixture was then ice to give the oily product and the orange poured to stop the reaction and the NH ₄ Cl, extracted with Et ₂ O (2x250 mL), concentrated under reduced pressure, and GC has the following composition: l- BuInd ^t, 0.3 %; 3- ^t BuInd, 2.8%; Bis (1-t-butyl-3-indenyl) methane, 78.3%; The rest is a byproduct.

The yield of the crude product was 83.6 g, which corresponds to a yield of 79.9%. The orange oily product crystallized upon standing (about 1 hour). The product obtained was further purified by washing with pentane to give bis (3-tert-butyl-1-indenyl) methane as a light yellow powder. 99.8% purity (by G.C).

(c) (1) Synthesis of methylene-bis (3-t-butyl-1-indenyl) zirconium dichloride (in Et ₂ O / pentane)

I1.0 g of pure bis (1-tert-butyl-3-indenyl) methane (30.9 mmol) obtained above was dissolved in 200 mL Et ₂ O in a 250 mL Schlenk tube and the solution cooled to -15 ° C. It was. 40 mL (63.3 mmol) of 1.6 M BuLi in hexanes were added dropwise over 15 minutes with stirring. The solution was warmed to room temperature and stirred for 4.5 h. Turbidity was increased to finally form a yellow suspension. 7.2 g ZrCl ₄ (30.9 mmol) was slurried in 200 mL pentane. Both mixtures were cooled to −80 ° C. and Li salt solution in Et ₂ O was quickly added to the ZrCl ₄ slurry in pentane. After 20 minutes of cooling bath removal, the color of the slurry changed from yellow to red. The reaction mixture was stirred overnight at room temperature and then dried under reduced pressure. Side arm to slurry the red powder in 200 mL of pentane and to connect the system above and below frit (which allows solvent reflux), bottom receiving flask and Transfer to a filtration device equipped with a top bubble condenser. The red solid was extracted with reflux pentane for about 3.5 hours. The filtrate was evaporated to dryness under reduced pressure to give a red paste containing rac-CH ₂ (3- ^t Bu-1-Ind) ₂ ZrCl ₂ , free of meso isomers but containing polymeric byproducts. The paste was washed twice with Et ₂ O (20+ 10 mL) to give 1 g of pure product. Furthermore, the red solid on frit was extracted with CH ₂ Cl ₂ and dried until the filtrate became bright orange (6 hours). ¹ H-NMR analysis shows the presence of pure rac-CH ₂ (3- ^t Bu-Ind) ₂ ZrCl ₂ (7.25 g).

The total yield (8.25 g of red powder) of rac-CH ₂ (3- ^t Bu-Ind) ₂ ZrCl ₂ was 52%.

¹ H NMR (CDCl ₃ , δ ppm): S, 1.41, ^t Bu, 18H; s, 4.78, CH ₂ , 2H; s, 5.79, 2 H, Cp-H; m, 7.15, 2H, m, 7.36, 2H; m, 7.47, 2 H; m, 7.78, 2 H.

(c) (2) Synthesis of methylene-bis (3-t-butyl-1-indenyl) zirconium dichloride (in Et ₂ O / toluene)

All operations proceeded in the dark with the glass covered with aluminum foil.

3.46 g of bis (1-tert-butyl-3-indenyl) methane (9,6 mmol) obtained above was dissolved in 60 mL of Et ₂ O in a 250 mL Schlenk tube and the solution was cooled to 0 ° C. . 8.8 mL (22.0 mmol) of 2.5 M BuLi in hexanes was added dropwise over 6 minutes with stirring. The resulting solution was warmed to rt and stirred for 24 h. Turbidity was increased to finally form an orange precipitate. 2.46 g ZrCl ₄ (10.6 mmol) was slurried in 60 mL of toluene. Both mixtures were cooled to −20 ° C. and ZrCl ₄ slurry in toluene was quickly added to the Li salt solution in Et ₂ O; At the moment, the slurry changed from orange to red. The cooling bath was maintained at -20 ° C for 25 minutes and then at -17 ° C for 20 minutes. The solution so obtained was warmed up to O ° C. and after 20 minutes the cooling bath was removed. The reaction mixture was kept at room temperature overnight under stirring; Et ₂ O was removed under reduced pressure and the toluene suspension obtained was filtered. The filtrate was dried under reduced pressure to give 3.26 g of red powder.

¹ H-NMR analysis shows the presence of pure rac-CH ₂ (3-t-Bu-Ind) ₂ ZrCl ₂ (yield 65.7%).

¹ H NMR (CD ₂ Cl ₂ , δ ppm): 1.37 (s, 18H, t-Bu); 4.79 (s, CH ₂ , 2H); 5.78 (s, Cp-H, 2H); 7.06-7.79 (m, 8 H).

The solubility of rac-CH ₂ (3-t-Bu-Ind) ₂ ZrCl ₂ in toluene was about 50 g / l.

The residue on the frit (red purple solid) was dried and ¹ H-NMR analysis showed that it contained two isomeric mesos: rac = 93: 7. The residue was washed with tetrahydrofuran and dried again to give the final product (1.2 g of red purple powder) containing pure meso CH ₂ (3-t-Bu-Ind) ₂ ZrCl ₂ (24.2% yield). ).

¹ H NMR (CD ₂ Cl ₂ , δ ppm): 1.48 (s, 18 H, t-Bu); 4.77 (d, J = 14.09, 1 H, CH); 5.09 (d, J = 14.09, 1H, CH); 5.86 (s, 2H, Cp-H); 6.87-7.67 (m, 8 H).

Synthetic 2

rac-methylene-bis (3-t-butyl-l-indenyl) hafnium dichloride

A crude product of 4.14 g bis (1-tert-butyl-3-indenyl) methane (78.3% pure product, 9.1 mmol) obtained as described in Synthesis 1 was added to 80 mL of Et ₂ O in a 100 mL Schlenk tube. Dissolved in and cooled to -20 ° C. 9.8 mL (24.5 mmol) of 2.5 M BuLi in hexane was added dropwise over 5 minutes with stirring. The solution was allowed to warm up to room temperature and stirred for 5 hours. The turbidity increased to form an orange suspension. 3.72 g HfCl ₄ (99.99% Hf, 11.62 mmol) was slurried in 80 mL of pentane. Both mixtures were cooled to −78 ° C. and Li salt solution in Et ₂ O was quickly added to the HfCl ₄ slurry in pentane. Two hours after the cooling bath was removed, the color of the slurry changed from yellow to orange. The reaction mixture was stirred overnight at room temperature and then dried under reduced pressure. Slurry the orange powder in 80 mL of pentane and stir for 15 minutes, the side arm (which allows the reflux of the solvent) to connect the system above and below the frit, the bottom receiving flask and the top bubble condenser Transfer to equipped filtration device. The filtered 80 mL of pentane solution was separated and the pentane dried to remove; The sticky product was obtained, washed with 4 mL of Et ₂ O, and then dried again to yield 0.4 g of orange powder with pure rac-CH ₂ (3- ^t Bu-1-Ind) ₂ HfCl ₂ .

¹ H NMR (CD ₂ Cl ₂ , δ ppm): 1.37 (s, ^t Bu, 18H); 4.78 (s, CH ₂ , 2H); 5.72 (s, 2H, Cp-H); 7.07-7.12 (t, Ar, 2H); 7.25-7.35 (t, Ar, 2H); 7.50-7.57 (d, 2 H); 7.7-7.8 (d, 2 H).

The remaining solid was extracted with refluxing CH ₂ Cl ₂ for about 3 hours. The filtrate was evaporated to dryness under reduced pressure to give a bright orange powder which was then washed with pentane to give 3.4 g of a 75/25 rac / meso mixture containing some polymeric material.

Synthetic 3

rac-methylene-bis (3-t-butyl-l-indenyl) titanium dichloride

6.1 g of pure bis (1-tert-butyl-3-indenyl) methane (16.0 mmol) obtained as described in Synthesis 1 is dissolved in 120 mL of Et ₂ O in a 250 mL Schlenk tube and the solution is- Cool to 20 ° C. 14.4 mL (36.0 mmol) of 2.5 M BuLi in hexanes was added dropwise over 10 minutes with stirring. The solution was allowed to warm up to room temperature and stirred for 5 hours. The turbidity increased to form an orange suspension. 1.88 mL of TiCl ₄ (17.0 mmol) was dissolved in 120 mL of pentane. Both mixtures were cooled to −80 ° C. and Li salt solution in Et ₂ O was quickly added to TiCl ₄ in pentane. The cooling bath was removed and the reaction mixture was kept stirring at room temperature overnight to give a dark brown mixture which was dried under reduced pressure. The dark brown powder is slurried in 100 mL of pentane and filtered with side arms (allowing reflux of the solvent) connecting the system above and below frit, bottom receiving flask and top bubble condenser Transferred to the device. The filtered 100 mL of pentane solution was separated and the pentane was dried to remove to give 3 g of a thick solid which was washed with 20 mL of Et ₂ O and then dried again to give 0.52 g of pure rac-CH ₂ ( 3- ^t Bu-1-Ind) ₂ TiCl ₂ was obtained.

¹ H NMR (CD ₂ Cl ₂ , δ ppm): 1.38 (s, ^t Bu, 18H); 4.91 (s, CH ₂ , 2H); 5.25 (s, 2 H, Cp-H); 7.02-7.12 (t, Ar, 2H); 7.3-7.5 (d + t, Ar, 4H); 7.70-7.75 (d, 2 H).

The remaining solid was extracted with refluxing CH ₂ Cl ₂ for about 3 hours. The filtrate was evaporated to dryness under reduced pressure to give 5.0 g of a thick powder, but because of the low purity, it was further washed with Et ₂ O (25 mL) to give 0.54 g of pure product. The collected yield was 14%.

Synthetic 4

rac-methylene-bis (3-t-butyl-l-indenyl) zirconium dimethyl

Et _{2-methyl-lithium} 1.6 M solution 3.06mL (4.9 mmoles) at a temperature of -78 ℃, 10 minutes 50 mL of Et ₂ of 1.2 g obtained in Synthesis 1 in the O rac-CH ₂ (3 throughout in the O -tert-butyl-1-indenyl) ₂ ZrCl ₂ (9.23 mmoles) was added to the solution containing. The reaction mixture was stirred at room temperature for 24 hours and finally a dark brown solution was obtained. The reaction mixture was then dried under reduced pressure to separate the brown solid which was extracted with pentane; Evaporation and drying under reduced pressure of the filtrate gave 0.56 g (51% yield) of a pale yellow solid, which was chemically pure rac -CH ₂ (3-tert-butyl-1-indenyl) ₂ in ¹ H-NMR analysis. Identified as ZrMe ₂

¹ H NMR (d, ppm, C ₆ D ₆ ): CH ₃ , s, -0.82, 6H; ^t Bu, s, 1.39, 18 ^H ; -CH _2- , s, 3.84, 2H; Cp-H, s, 5.49, 2H; Ar, t, d, t, 6.7-7.2, 6H; d, 7.7-7.8, 2 H.

Synthetic 5

rac-methylene-bis (4,7-dimethylindenyl) zirconium dichloride

(a) Synthesis of Bis (4,7-dimethylindenyl) methane

Paraformaldehyde (2.08 g, 69.4 mmol) was added at 25 ° C. to a mixture of 4,7-dimethylindene (25.0 g, 174 mmol) and EtONa (5.9 g, 87 mmol) in DMSO (200 mL). After stirring at room temperature for 12 hours, the reaction mixture was heated at 65 ° C. for 8 hours. Then it was cooled to room temperature and a solution of HCl (1 M, 400 mL) was added. The mixture is extracted with CH ₂ Cl ₂ (400 mL); The organic phases were combined, washed with saturated NaCl solution and then washed with water, dried over MgSO ₄ , filtered and finally concentrated to give a brown viscous liquid. GC analysis shows only the final product and starting material, no fulvene derivatives were found. Precipitation occurred when the brown liquid was placed in pentane (100 mL). After filtration and washing with pentane and EtOH bis (4,7-dimethylindenyl) methane was obtained as a yellow solid. Yield 33% (6.8 g).

¹ H NMR (CDCl ₃ , δ ppm): 6.85-7.05 (m, 4 H), 6.35 (s, 2 H), 4.20 (s, 2 H), 3.2 (s, 4 H), 2.55 (s, 6 H ), 2.35 (s, 6 H).

(b) Synthesis of methylene-bis (4,7-dimethylindenyl) zirconium dichloride

A suspension in THF (30 mL) of bis (4,7-dimethyl-indenyl) methane (2 g, 6.7 mmol) obtained above was added to a stirred suspension of KH (0.6 g, 15 mmol) in THF (35 mL). Add via cannula. After the hydrogen evolution ceased (2 hours), the resulting brown solution was separated from excess KH. Both the solution and ZrCl ₄ (THF) ₂ (2.5 g, 6.7 mmol) solution in THF (65 mL) were added dropwise to a flask containing THF (30 mL) under vigorous stirring over 4 hours through a dropping funnel. . After addition, the mixture was stirred overnight. Brick-red solutions and precipitates formed. After concentration to about 4 mL in vacuo, 10 mL of Et ₂ O was added; The suspension was filtered and the residue was dried in vacuo to give a brown powder. The powder was washed with refluxing CH ₂ Cl ₂ until the wash was colorless. The CH ₂ Cl ₂ solution was concentrated to 7 mL and cooled to −20 ° C. overnight. Filtration separated 0.715 g of methylene-bis (4,7-dimethylindenyl) zirconium dichloride as a red solid. Formation of pure racemic isomers was confirmed by ¹ H NMR analysis.

¹ H NMR (CDCl ₃ , δ ppm): 7.00, 6.97 (d, 2H), 6.78, 6.74 (d, 2H), 6.66, 6.64 (d, 2H), 5.89, 5.87 (d, 2H), 5.09 (s , 2H), 2.76 (s, 6H), 2.30 (s, 6H).

Synthetic 6

rac-methylene-bis (l-phenyl-5,7-dimethyl-indenyl) zirconium dichloride

(a) Synthesis of 5,7-dimethylindan-l-one

A mixture of 3-chloropropionyl chloride (118.9 g, 0.94 mol) and p-xylene (100 g, 0.94 mol) in CH ₂ Cl ₂ (200 mL) was dissolved in AlC1 ₃ (283 g, 2.12 mol) at 0 ° C. Added dropwise. The reaction mixture was then stirred at room temperature for 12 hours. The resulting slurry was poured into a flask containing 1.5 kg of ice. The product was extracted with Et ₂ O (2 × 800 mL); The combined organic layers were washed with a saturated solution of NaHCO ₃ (800 mL) and then with water (800 mL), dried over MgSO ₄ , filtered and concentrated to give 175 g of viscous liquid. The product was used in the next step without further purification.

400 mL of concentrated sulfuric acid was added dropwise to the product obtained above. The solution was heated at 65 ° C. for 5 hours. The reaction mixture was then cooled to room temperature and poured slowly into a flask containing 2 kg of ice. The mixture is extracted with CH ₂ Cl ₂ (2 × 1000 mL); The combined organic phases were washed with saturated NaHCO ₃ solution and then washed with water, dried over MgSO ₄ , filtered and finally concentrated. 5,7-Dimethylindan-l-one was isolated by crystallization from hexanes (71.4 g, 47% yield).

¹ H NMR (CDCl ₃ , δ ppm): 7.1 (s, 1H), 6.9 (s, 1H), 2.9-3.1 (m, 2 H), 2.6-2.7 (m, 2 H), 2.55 (s, 3 H), 2.4 (s, 3H).

(b) Synthesis of 3-phenyl-4,6-dimethylindene

5,7-Dimethylindan-1-one (13.5 g, 84.4 mmol) obtained above in THF (20 mL) was added dropwise to a solution of PhMgBr (3.0 M, 63 mL, 188 mmol) in Et ₂ O at 0 ° C. The reaction mixture was stirred at room temperature overnight and then the reaction was stopped with saturated ammonium chloride solution (600 mL). The mixture was extracted with Et ₂ O ( ₂ × 500 mL); The organic phases were combined, dried over MgSO ₄ and concentrated to give a viscous liquid. The product was used in the next step without further purification.

A mixture of this product (16 g) and p-toluenesulfonic acid monohydrate (2.6 g) in benzene was heated at reflux for 3 hours. The mixture was cooled to rt and then treated with saturated NaHCO ₃ solution. The organic layer was washed with water, dried over MgSO ₄ , concentrated and vacuum distilled to give 3-phenyl-4,6-dimethylindene (11.6 g, 78% at bp 120 ° C. 0.5 mmHg).

(c) Synthesis of Bis (1-phenyl-5,7-dimethyl-indenyl) methane

Paraformaldehyde (68 mg, 2.27 mmol) was obtained above at 25 ° C. in DMSO (15 mL) 3-phenyl-4,6-dimethylindene (1.0 g, 4.55 mmol) and EtONa (0.15 g, 2.27 mmol). After stirring for 4 hours at room temperature, the reaction mixture was treated with HCl (1 M, 100 mL) solution. The mixture was extracted with CH ₂ Cl ₂ (2 × 100 mL); The organic layers were combined, washed with saturated NaCl solution and then washed with water, dried over MgSO ₄ , filtered and finally concentrated to give a brown viscous liquid. Precipitation and filtration in MeOH gave 0.45 g of bis (l-phenyl-5,7-dimethyl-indenyl) methane as a solid. (Yield 44%)

¹ H NMR (CDCl ₃ , δ ppm): 7.7 (m, 14 H), 6.25 (s, 2 H), 4.5 (s, 2 H), 3.8 (s, 2 H), 2.35 (s, 6 H) , 2.0 (s, 6 H).

(d) Synthesis of methylene-bis (3-phenyl-4,6-dimethyl-indenyl) zirconium dichloride

2.5 g of bis (1-phenyl-5,7-dimethyl-indenyl) methane (5.53 mmol) obtained above were dissolved in 25 mL of THF and 0.5 g KH in 10 mL THF in 50 mL of Schlenk tubes ( 12.5 mmol) was added slowly to the suspension. After 2 hours the evolution of H ₂ ceased and the resulting brown solution was separated from excess KH. Both the solution and the ZrCl ₄ (THF) ₂ (2.08 g, 5.53 mmol) solution in THF (35 mL) were added dropwise through a dropping funnel to a 250 mL flask with THF (35 mL) over 6 hours under heavy stirring. do. After the addition was complete, the mixture was stirred at room temperature overnight. A red cloudy solution was obtained. After drying under reduced pressure, the residue was extracted with refluxing CH ₂ Cl ₂ until the wash was colorless. The CH ₂ Cl ₂ solution was dried and extracted with pentane refluxing the residue for 10 hours. The pentane solution was concentrated to 10 mL. The precipitated product was filtered and dried in vacuo to yield 0.4 g of red rac-CH ₂ (3-phenyl-4,6-dimethyl-1-ind) ₂ ZnCl ₂ free of meso isomers. ¹ H NMR (CDCl ₃ , δ ppm): 2.09 (s, CH ₃ ); 2.64 (s, CH ₃ ); 4.78 (s, 2H, CH ₂ ); 5.80 (s, 2 H, Cp-H); 6.85 (s, 2 H); 7.04 (s, 2 H); 7.30 (m, 6 H); 7.44 (m, 4 H).

Synthesis 7

rac-methylene-bis (2-methyl-1 -indenyl) zirconium dichloride

(a) Synthesis of Bis (2-methyl-indenyl) methane

3.06 g of NaOEt (45.0 mmol) and 30.00 g of 2-methylindene (224.9 mmol) dissolved in 600 mL of DMF were introduced into a 1000 mL flask with a stir bar in this order at room temperature. 9.10 mL of aqueous formalin (37%, 112.1 mmol) was added dropwise: A slight exothermic reaction was observed and the solution turned dark brown. At the end of the addition, the reaction mixture was stirred at room temperature for 2 hours. The reaction was then stopped by pouring the mixture into ice and NH ₄ Cl. The organic product was extracted with Et ₂ O (3 × 20 ml) and the aqueous layer was washed with Et ₂ O; The combined organic layers were washed with water to remove remaining DMF, then dried over MgSO ₄ , filtered and finally concentrated to give 30.54 g of orange-brown oil. The oil was washed with 100 ml of pentane and dried again. GC analysis showed that the final product (12.02 g of white powder) was a crude product of bis (2-methyl-indenyl) methane, more specifically: 85.3% bis (2-methyl-indenyl) methane and 12.1% trimer Shows.

¹ H NMR (CDCl ₃ , δ ppm): 2.15 (s, 6H, CH ₃ ); 3.31 (s, CH ₂ , 4H); 3.74 (s, 2H, CH ₂ bridge); 7.10-7.36 (m, 8H).

GC-MS: m / z (%) = 272 (M ⁺ ), 143 (M ⁺ -C ₁₀ H ₉ ), 128 (M ⁺ -C ₁₁ H ₁₂ ), 115 (C ₉ H ₇ ⁺ ).

(b) Synthesis of rac-methylene-bis (2-methyl-1-indenyl) ZrCl ₂ .

2.11 g of bis (2-methyl-indenyl) methane (by 90.6% GC, 7.8 mmol) crude product is dissolved in 50 ml of Et ₂ O in a 100 ml Schlenk tube and the solution is cooled to -70 ° C. I was. 10.2 ml (16.3 mmol) of 1.6 M BuLi in hexanes were added dropwise under stirring. The resulting solution was allowed to warm up to room temperature and stirred for 3 hours. Turbidity increased to form a pale yellow suspension. 1.80 g ZrCl ₄ (7.7 mmol) was slurried in 30 ml of pentane. The two mixtures were cooled to −70 ° C. and Li salt solution in Et ₂ O was quickly added to the ZrCl ₄ slurry in pentane: at the moment the slurry changed from yellow to orange-red. The cooling bath was removed. The reaction mixture was kept at room temperature overnight under stirring and the color of the suspension changed from yellow to orange. After filtration (the filtrate was removed), the residue was extracted with toluene and the filtrate obtained was evaporated to dryness under reduced pressure to yield 1.30 g of orange powder. ¹ H-NMR analysis shows the presence of rac / meso CH ₂ (2-Me-1-Ind) ₂ ZrCl ₂ = 75/25. (Yield 38.5%).

Synthesis 8

rac-methylene-bis (3-trimethylsilyl-l-indenyl) zirconium dichloride

(a) Synthesis of Bis (1-trimethylsilyl-3-indenyl) methane

9.56 g bis (1-indenyl) methane (39.1 mmol) obtained in Synthesis 10 was dissolved in 70 ml Et ₂ O in 250 ml Schlenk tubes and the solution was cooled to -78 ° C.

33.0 ml (82.5 mmol) of 2.5M BuLi in hexanes were added dropwise over 30 minutes with stirring. The resulting solution was brought to room temperature and then stirred for 3 hours to give a brown thick, slightly turbid solution. 10.5 ml of chlorotrimethylsilane (82.7 mmol) was dissolved in 50 ml of Et ₂ O. 2 The mixture is cooled to -78 ℃, the Li salt solution in Et ₂ O was added to the chlorotrimethylsilane solution in Et ₂ O over 20 min; The color of the solution changed from brown to brown. The cooling bath was removed and the reaction mixture was stirred overnight at room temperature. After 20 hours, the slightly cleared solution was quenched with several ml of MeOH, filtered and concentrated to give 11.28 g of bis (l-trimethylsilyl-3-indenyl) methane as a brown thick oil. (Yield 74.2%, meso / rac = 1/1).

¹ H NMR (CDCl ₃ , δ, ppm): -0.04 to -0.03 (s, 18H, CH ₃ ); 3.35-3.45 (m, 2H, CH or CH ₂ bridge); 3.93-4.00 (bs, 2H, CH ₂ bridge or CH); 6.30-6.40 (m, 2H, Cp-H); 7.10-7.50 (m, 8 H).

(b) Synthesis of CH ₂ (3-Me ₃ Si-Ind) ₂ ZnCl ₂

4.90 g of bis (1-trimethylsilyl-3-indenyl) methane (12.6 mmol) obtained above was dissolved in 70 ml of Et ₂ O in a 250 ml Schienk tube and the solution was cooled to -70 ° C. 10.6 ml (26.5 mmol) of 2.5 M BuLi in hexanes were added dropwise under stirring. The solution was allowed to come to room temperature and stirred for 3 hours. Turbidity increased to form a brown thick suspension. 2.94 g ZrCl ₄ (12.6 mmol) was slurried in 50 ml of pentane. Both mixtures were cooled to −70 ° C. and Li salt solution in Et ₂ O was quickly added to the ZrCl ₄ slurry in pentane; The cooling bath was then removed. The reaction mixture was kept at room temperature overnight under stirring and the color of the suspension turned brown. After filtration, the residue was concentrated and then extracted with toluene to give a pink-red powder. ¹ H-NMR analysis shows the presence of meso / rac CH ₂ (3-Me ₃ Si-1-Ind) ₂ ZrCl ₂ = 75/25.

The filtrate was dried to give a thick sticky solid and pentane was added; The resulting mixture was stirred at room temperature for 1 hour and then filtered. The residue was finally dried to give 1.87 g of orange powder. ¹ H-NMR analysis shows the presence of rac / meso CH ₂ (3-Me ₃ Si-1-Ind) ₂ ZrCl ₂ = 81/19. (Yield 27.0%)

¹ H NMR (CD ₂ Cl ₂ , δ, ppm): 0.22 (s, 6H, CH ₃ ); 0.34 (s, 6H, CH ₃ ); 4.79 (s, CH ₂ bridge, 2H); 4.93 (q, CH ₂ bridge, 2H); 6.47 (s, Cp-H, 2H); 6.57 (s, Cp-H, 2H); 7.06-7.72 (m, 16 H).

Synthesis 9

rac-methylene-bis (2-methyl-3-trimethylsilyl-l-indenyl) zirconium dichloride

(a) Synthesis of Bis (2-methyl-3-trimethylsilyl-l-indenyl) methane

6.32 g of bis (2-methyl-1-indenyl) methane (23.2 mmol) was dissolved in 70 ml of Et ₂ O in 250 ml of Schlenk tubes and the white suspension was cooled to -50 ° C. 19.5 ml of 2.5 M BuLi (48.8 mmol) in hexane was added dropwise over 20 minutes with stirring. The suspension was brought to room temperature and stirred for 3 hours. The final suspension was slightly yellow. 6.2 ml of chlorotrimethylsilane (48.8 mmol) were dissolved in 50 ml of Et ₂ O. Cooling the mixture to -50 ℃ 2 and was added to the Li salt suspension in Et ₂ O to the chlorotrimethylsilane solution in Et ₂ O. The cooling bath was removed and the reaction mixture was stirred overnight at room temperature. The reaction mixture, then colored yellow, was quenched with several ml of MeOH, filtered and concentrated to yield 9.36 g of a brown viscous liquid (yield 96.8%).

¹ H NMR (CDCl ₃ , δ, ppm): -0.06, -O.04 (s, 9H, Si (CH ₃ ) ₃ ); 2.21,2.23 (s, 3H, CH ₃ ); 3.32 (s, 2H, CH or CH ₂ bridges); 3.83 (s, 2H, CH ₂ bridge or CH); 7.05-7.36 (m, 8 H).

(b) Synthesis of rac-methylene-bis (2-methyl-3-trimethylsilyl-1-indenyl) ZrCl ₂

9.36 g of bis (2-methyl-3-trimethylsilyl-l-indenyl) methane (22.5 mmol) prepared above was dissolved in 80 ml of Et ₂ O in 250 ml of Schlenk tubes and the solution- Cool to 20 ° C. 18.9 ml (47.2 mmol) of 2.5 M BuLi in hexanes were added dropwise under stirring. The solution was brought to room temperature and kept stirring for 3 hours. The color of the solution changed from brown to orange. 5.24 g ZrCl ₄ (22.5 mmol) was slurried in 50 ml pentane. The two mixtures were cooled to −70 ° C. and Li salt solution in Et ₂ O was quickly added to the ZrCl ₄ slurry in pentane; The cooling bath was then removed.

The reaction mixture was stirred overnight at room temperature resulting in a brick-red suspension. After filtration, the filtrate was dried to give a brown sticky solid (removed); The residue was concentrated and extracted with toluene to yield 9.18 g of brown powder. ¹ H-NMR analysis shows the presence of rac / meso CH ₂ (2-Me-3-Me ₃ Si-1-Ind) ₂ ZrCl ₂ = 95/5. (Yield 70.7%)

¹ H NMR (CD ₂ Cl ₂ , δ, ppm): 0.32, 0.42 (s, 9H, Si (CH ₃ ) ₃ ); 2.24,2.49 (s, 6H, CH ₃ ); 4.93 (s, CH ₂ bridge, 2H); 5.10 (d, 2H, CH ₂ bridge); 7.04-7.72 (m, 16 H).

Synthesis 10

rac-methylene-bis (l-indenyl) zirconium dichloride

(a) Synthesis of Bis (1-indenyl) methane

3.5 g of formalin (37% solution, 43.1 mmol) was added to a mixture of 10.0 g of indene (86.2 mmol) and 2.9 g of EtONa (43.1 mmol) in 100 mL of DMF. The reaction mixture was stirred at room temperature for 12 hours. HCl solution (1 M, 50 mL) was added. The mixture was extracted with CH ₂ Cl ₂ (2 × 100 mL) and the organic phases were combined, washed with saturated NaCl solution and then washed with water, dried over MgSO ₄ , filtered and finally concentrated to give bis (1-indenyl) methane Obtained as a viscous brown liquid. (Yield 89% by GC). Vacuum distillation gave the pure product as an oil with a yellow viscosity (bp 160-180 ° C., at 1.2 mmHg, 3.65 g, 35% yield). It was recrystallized from pentane.

¹ H NMR (CDCl ₃ ,, ppm): 7.10-7.60 (m, 8H), 6.25 (s, 2H), 3.85 (s, 2H), 3.40 (s, 4H).

(b) Synthesis of methylene-bis (1-indenyl) zirconium dichloride

2.135 g of bis (1-indenyl) methane (8.75 mmol) obtained above were dissolved in 30 mL of THF and 0.8 g of KH (19.5 mmol) in 50 mL of THF with stirring in 100 mL Schlenk tube. It was added slowly to the suspension. After about 1 hour and 30 minutes the evolution of H ₂ ceased and the resulting brownish solution was separated from excess KH. The solution and a solution of ZrCl ₄ (THF) ₂ (3.3 g, 8.75 mmol) in THF (80 mL) were added dropwise through a dropping funnel into a 250 mL flask containing THF (20 mL) over 5.5 hours with vigorous stirring. After the addition was completed, the mixture was stirred at room temperature overnight. A yellow-orange solution and a precipitate formed. The suspension was concentrated to about 10 mL under reduced pressure, then 10 mL of Et ₂ O was added; The suspension was filtered and the residue was dried in vacuo and extracted with refluxing CH ₂ Cl ₂ until the wash was colorless (2 hours). The CH ₂ Cl ₂ solution (some of the product precipitated during the extraction) was concentrated to yield 2.135 g of a red solid product. The product was washed with Et ₂ O (3 × 5 mL), 2 mL CH ₂ Cl ₂ , again Et ₂ O to afford 1.06 g of methylene-bis (1-indenyl) zirconium dichloride with some organic impurities. Crystallization with toluene gave 0.32 g of red-orange rac-CH ₂ (1-Ind) ₂ ZrCl ₂ free of meso isomers. ¹ H NMR (CD ₂ Cl ₂ , δ, ppm): 4.87 (s, 2H, CH ₂ ); 6.02-6.04 (d, 2 H); 6.59-6.61 (d, 2 H); 7.1-7.7 (3 m, 8 H).

Polymerization test

Methyl Alumoxane (MAO)

Commercially available (Witco) 10% toluene solution was dried until a solid glassy material was obtained, then crushed finely, and then processed in vacuo again to remove all volatiles (4-6 hours, 0.1 mmHg, 50 ° C). Free flowing powder was obtained.

Tris (2,4,4-trimethyl-pentyl) aluminum (TIOA)

Commercial (Witco) samples were diluted in 1 M solution and used in the solvents indicated.

Tris (2-methyl-propyl) aluminum (TIBA)

A commercial product was purchased from Witco and used as a 1M solution in hexanes.

PhNMe ₂ H / B (C ₆ F ₅ ) ₄

A commercial product was purchased from Asahi Glass Co.

Example 1-6

Ethylene polymerization

The 200 ml glass autoclave provided with magnetic stirrer, temperature sensor and feed line for ethylene feed was cleaned and ethylene flowed at 35 ° C. 90 ml of hexane were introduced at room temperature. The catalyst system continuously introduces the cocatalysts reported in Table 1 in 10 ml of hexane and stirred for 5 minutes followed by the introduction of a bridged metallocene compound dissolved in the smallest possible amount of toluene reported in Table 1 Made individually. After stirring for 5 minutes, the solution was introduced into the autoclave under ethylene flow; Close the reactor; The temperature was raised to 80 ° C. and pressurized to 4.6 barg. The total pressure was kept constant by feeding ethylene. After the polymerization time shown in Table 1, the reactor was cooled and degassed, and the polymerization was stopped by introducing 1 ml of methanol. The product is washed with acidic methanol, then with methanol and finally dried under vacuum at 60 ° C. The yield of the polymerization reaction and the properties of the polymer obtained are shown in Table 1.

Example 7

Ethylene / 1-hexene Copolymerization

Introducing 80 ml of heptane and 10 ml of 1-hexene into the autoclave instead of 90 ml of hexane; The catalyst system was prepared in 10 ml of heptane instead of hexane, the polymerization was carried out at 70 ° C. and 45 barg; Example 1 was repeated except stopping after 10 minutes. 1.0 g corresponding to an activity of 339.9 kg / mmol _zr · h was obtained. The intrinsic viscosity of the copolymer was 2.59 dL / g. The unit of 1-hexene in the copolymer was 13.7 wt%.

Example 8

Ethylene / Propylene Copolymerization

The copolymerization was carried out by continuously feeding the monomer mixture at steady flow in a 250 ml glass reactor equipped with a stirrer and thermometer. A cocatalyst was prepared by dissolving in 3.45 mL of TIOA (1M in hexane) in 5 ml of toluene and then stirring for 10 minutes with addition of 0.031 mL of water. The cocatalyst was then introduced to a nitrogen purged reactor containing 95 mL of toluene. When the reactor was placed in a thermostat bath and a reaction temperature of 50 ° C. was reached, an ethylene propylene mixture containing 60% by weight of ethylene was continuously fed to reach a total pressure of 80 mm Hg and a flow rate of 80 L / h. 1.8 mg (3.45 μmol) of rac-methylene-bis (3-t-butyl-indenyl) zirconium dichloride was dissolved in 5 ml of toluene and added at the start of the polymerization. After 15 minutes, the polymerization reaction was stopped by addition of 1 ml of methanol, the copolymer was coagulated in acidified methanol and then filtered and dried under vacuum. Yield was 2.42 g. The intrinsic viscosity of the copolymer was 2.9 dL / g. The amount of propylene units in the copolymer was 18.3 wt%.

Examples 9-10, 15-23 and 29-33 and Comparative Examples 11-14 and 24-28

Propylene polymerization

200 g of propylene were charged into a jacketed stainless steel autoclave and 35-mL stainless steel vial equipped with a 1-L stirrer and connected to a thermostat for temperature control; The autoclave was first rinsed thoroughly with a TIBA solution in hexane, dried at 50 ° C. in an air stream of propylene, and finally cooled to room temperature (Examples 16-23 and 29-33, using a 4.25-L autoclave and propylene It was filled in so that at the polymerization temperature, the volume of liquid propylene was 2 L). In use, hydrogen was charged to the reactor before imposing liquid propylene at room temperature. The autoclave was adjusted to the polymerization temperature shown in Table 2. A certain amount of racemic zirconocene dichloride shown in Table 2 was added to the MOA solution in toluene to prepare a catalyst mixture, and the solution thus obtained was stirred at room temperature for 10 minutes, and the stainless-steel vial by nitrogen pressure at the polymerization temperature. Was injected into the autoclave through. The polymerization was carried out at constant temperature for 1 hour and stopped with carbon monoxide. The unreacted monomer was taken out and then the reactor was cooled to room temperature and the polymer was dried at 60 ° C. under reduced pressure. Polymerization data are as shown in Table 2. Data relating to the properties of the polymers obtained are shown in Table 3.

Ethylene Polymerization Example rac-zirconocene dichloride Zr (mg) Cocatalyst Cocatalyst (mmol) Minutes Yield (g) Active (kg / g _zrh ) I.V. (dL / g) 123456 CH ₂ (3-tBuInd) ₂ 〃〃〃CH ₂ (3-TMS-Ind) ₂ CH ₂ (3-TMS-2-Me-Ind) ₂ 0.10.10.30.30.10.1 MAOTIOA / H ₂ O ^* MAOB (C ₆ F ₅ ) ₄ MAOMAO 0.210.970.12 ** 00 8633610 2.121.161.660.842.171.84 900.8657.2629.0317.31088.2698.3 6.57.9n.d.7.12.23.2

* 0.46 mmol of H ₂ O added to 0.97 mmol of TIOA (1M in heptane);

** PhNMe ₂ H / B (C ₆ F ₅ ) ₄ was used with 0.31 mmol in a molar ratio of B / Zr =.

Synthesis of Polypropylene Example rac-zirconocene dichloride Zr (mg) Al / Zr (mol) H ₂ (mL) T (℃) Yield (g) Activity (kg / g _cath ) 910 Compound 11 Compound 12 Compound 13 Compound 1415161718 1920 212 223 Compound 24 Compound 25 Compound 26 Compound 27 Compound 282 930 313 233 CH ₂ (4,7-Me ₂ Ind) ₂ ZrCl ₂ 〃CH ₂ (Ind) ₂ ZrCl ₂ 〃C ₂ H ₄ (4,7-Me ₂ Ind) ₂ ZrCl ₂ 〃CH ₂ (3-Ph-4, 6-Me ₂ Ind) ₂ ZrCl ₂ CH ₂ (3-tBuInd) ₂ ZrCl ₂ 〃〃〃〃〃〃〃Me ₂ C (3-tBuInd) ₂ ZrCl ₂ 〃〃〃〃CH ₂ (3-tBuInd) ₂ ZrCl ₂ 〃CH ₂ (3-tBuInd) ₂ ZrMe ₂ 〃〃 1.10.20.50.21.00.51.02.02.02.01.51.52.02.02.00.20.20.10.20.164444 20005000400010002000200050001000100010001000300050050050080008000800080008000250200200200200 * 00000000000005010000000000700 50705070507050304060706060606030405060706060606060 58.645.876.617.6142.720.877.664.7105.7176.7138.8209.0123.9196.0186.925.341.322.959.020.2300120200208300 512291538814342127325388921396298931262062292952025030505275

Synthesis of propylene Example rac-zirconocene dichloride I.V. (dL / g) Mv Mn mmmm (%) R.I. (%) Tm (℃) 910 Compound 11 Compound 12 Compound 13 Compound 1415161718 1920 212 223 Compound 24 Compound 25 Compound 26 Compound 27 Compound 282 930 313 233 CH ₂ (4,7-Me ₂ Ind) ₂ ZrCl ₂ 〃CH ₂ (Ind) ₂ ZrCl ₂ 〃C ₂ H ₄ (4,7-Me ₂ Ind) ₂ ZrCl ₂ 〃CH ₂ (3-Ph-4, 6-Me ₂ Ind) ₂ ZrCl ₂ CH ₂ (3-tBuInd) ₂ ZrCl ₂ 〃〃〃〃〃〃〃Me ₂ C (3-tBuInd) ₂ ZrCl ₂ 〃〃〃〃CH ₂ (3-tBuInd) ₂ ZrCl ₂ 〃CH ₂ (3-tBuInd) ₂ ZrMe ₂ 〃〃 n.m.n.m.0.110.090.120.140.23.922.321.030.790.841.070.950.901.741.180.890.530.330.871.051.051.061.20 n.d.n.d.n.d.n.d.n.d.n.d.n.d.6626003262001089007610082600114610976009070021010013080089400444002340087000112000112000113000134000 200023503200280034002800n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d.n.d. 85.984.471.4n.d.92.390.7n.d.97.898.296.497.0n.d.n.d.n.d.n.d.91.393.194.895.596.8n.d.96.597.097.0n.d. 0.821.120.47n.d.1.862.4n.d.000000000000000000 122n.d.n.d.n.d.131n.d.n.d.163160156154159159158158157156152148140n.d.157157158n.d.

n.m. = Not measurable

n.d. = Not measured

Claims (21)

Bridged metallocene compounds of formula (I) [Formula I] [Wherein, R ¹ and R ² are the same as or different from each other, a hydrogen atom, a linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ ~C ₂₀ is a group selected from alkyl, aryl and C ₇ ~C ₂₀ aryl group consisting of an alkyl group, which may include Si or Ge atoms; Substituents R ³ and R ⁴ are condensed, 5- to 8-membered, aliphatic, aromatic or heterocyclic rings which may be substituted, provided that R ¹ and R ² are hydrogen atoms and the condensed ring is a benzene ring When benzene is substituted at the ortho or meta position relative to the carbon atom of the cyclopentadienyl group linked to R ⁴ ; M is a transition metal belonging to groups 3, 4, 5 or lanthanide or actinide group in the Periodic Table of Elements (new IUPAC notation); The groups X are the same or different from each other and are a single anionic sigma ligand selected from the group consisting of hydrogen, halogen, -R, -OR, -OSO ₂ CF ₃ , -OCOR, -SR, -NR ₂ and PR ₂ groups, wherein R Is a C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₂ -C ₂₀ alkenyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl or C ₇ -C ₂₀ arylalkyl group, which are Si Or may comprise a Ge atom; And p is an integer of 0 to 3, and is equal to the value of 2 minus the oxidation state of the metal M]. The bridged metallocene compound of claim 1, wherein R ³ and R ⁴ form a condensed benzene ring which may be substituted. 3. The bridged metallocene compound of claim 1 or 2, wherein M is Ti, Zr or Hf. The bridged metallocene compound according to any one of claims 1 to 3, wherein the substituent X is a chlorine atom or a methyl group. A bridged metallocene compound of claim 1 having the formula [Formula III] [Wherein R ² is not hydrogen, R ¹ , R ² , M, X and p have the meaning reported in claim 1; Substituents R ⁵ are the same or different from each other and are linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl and C _7- A group selected from the group consisting of C ₂₀ arylalkyl groups, which may comprise Si or Ge atoms, or the substituent R ⁵ in two bisinal positions may form a 5-8 membered ring; n is an integer of 0 to 4] 6. A compound according to claim 5, wherein R ² is three linear or branched, saturated or unsaturated C ₁ -C ₁₀ alkyl, C ₅ -C ₁₂ cycloalkyl, C ₆ -C ₁₂ aryl, C ₇ -C ₁₂ alkylaryl or C _A bridged metallocene compound characterized by being a C, Si or Ge atom substituted with a ₇ to C ₁₂ arylalkyl group. The bridged metal according to claim 6, wherein R ² is selected from the group consisting of tert-butyl, trimethylsilyl, trimethylgeryl, 2,2-dimethyl-propyl and 2-methyl-2-phenyl-ethyl. Rosen compound. 8. The metallocene compound according to claim 7, which is rac-methylene-bis (3-t-butyl-indenyl) zirconium dichloride. The bridged metallocene compound of claim 1 having the formula III: [Formula III] [Wherein R ² is hydrogen and R ¹ , M, X and p have the meaning reported in claim 1; Substituents R ⁵ are the same or different from each other and are linear or branched, saturated or unsaturated C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ alkylaryl and C _7- A group selected from the group consisting of C ₂₀ arylalkyl groups, which may comprise Si or Ge atoms, or the substituent R ⁵ in two bisinal positions, may form a 5-8 membered ring; n is an integer of 0 to 4] 10. The bridged metallocene compound of claim 9, wherein the R ⁵ groups at positions 4 and 7 of the indenyl moiety are not hydrogen. 11. The bridged metallocene compound of claim 10, wherein the R ⁵ groups at positions 4 and 7 of the indenyl moiety are methyl, ethyl or phenyl. 12. The compound of claim 11, which is rac-methylene-bis (4,7-dimethyl-indenyl) zirconium dichloride. A process for preparing the metallocene compound of formula (I) according to claim 1, comprising reacting a ligand of formula (IV) with a compound of formula MX _{p + 2} , wherein M, X and P are as defined above . [Formula IV] [Wherein R ¹ , R ² , R ³ and R ⁴ have the meanings reported at, A is a suitable leaving group and two double bonds are allowed for each of the cyclopentadienyl rings of the ligand In position]. Ligands of formula (II) and their double bond isomers, except bis (3-t-butyl-indenyl) methane: [Formula II] [Wherein R ¹ , R ² , R ³ and R ⁴ have the meanings reported above] A catalyst system for olefin polymerization containing a product obtainable by contacting: (A) at least one bridged metallocene compound of formula (I) or (III) according to any one of claims 1 to 12; And (B) Proper activation cocatalyst. 16. The catalyst system of claim 15, wherein the activating cocatalyst is a compound capable of forming alum oxane and / or alkylmetallocene cations. A process for polymerizing olefins comprising polymerization of at least one olefin monomer in the presence of a catalyst system as claimed in claim 15. 18. The process of claim 17, wherein the olefin monomer is propylene. 19. The process according to claim 18, wherein propylene is polymerized in the presence of the bridged metallocenes according to any one of claims 5-8. A method for oligomerization of an olefin consisting of oligomerizing one or more olefin monomers in the presence of the bridged metallocene compound according to any one of claims 9 to 12. 21. The method of claim 20, wherein said olefin is propylene.