&pgr;-complex compounds

Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...

Reexamination Certificate

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C502S117000, C502S120000, C502S152000, C526S133000, C526S134000, C526S160000, C526S161000, C526S348200, C526S352000, C526S943000, C534S011000, C534S015000, C556S007000, C556S008000, C556S014000, C556S020000, C556S027000, C568S001000, C568S008000, C568S012000

Reexamination Certificate

active

06423659

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to compounds in which a transition metal is complexed with two &pgr; systems. particularly with aromatic &pgr; systems (metallocenes), and the two systems are reversibly joined to each other by at least one bridge comprising a donor and an acceptor, wherein at least one of the donor or acceptor atoms is part of the associated &pgr; system in each case. The coordinate bond which is formed between the donor atom and the acceptor atom produces a positive (partial) charge on the donor group and produces a negative (partial) charge on the acceptor group:
The present invention further relates to the use of these new &pgr;-complex compounds, particularly of new metallocenes. as polymerisation catalysts.
BACKGROUND OF THE INVENTION
Metallocenes have long been known as &pgr;-complex compounds, as has their use in the polymerisation of olefines (EP-A 129 368 and the literature cited therein). Furthermore, it is known from EP-A 129 368 that metallocenes, in combination with aluminium alkyl/water systems as co-catalysts, constitute effective systems for the polymerisation of ethylene (thus, for example, methylaluminoxane=MAO is formed from about 1 mole of trimethylaluminium and 1 mole of water. Other stoichiometric ratios have also been successfully used (WO 94/20506)). Moreover, metallocenes are already known which comprise cyclopentadienyl skeletons which are covalently linked to each other by a bridge. As an example of the numerous patents and patent applications in this field, EP-A 704 461 should be mentioned, wherein the linking group cited therein constitutes a (substituted) methylene group or ethylene group, a silylene group, a substituted silylene group, a substituted germylene group or a substituted phosphine group. In EP-A 704 461, bridged metallocenes are also provided as polymerisation catalysts for olefines. Despite the numerous patents and patent applications in the field, there is a continuing desire for improved catalysts which are distinguished by a high activity, so that the amount of catalyst remaining in the polymer is small, and which at the same time are suitable for the polymerisation and copolymerisation of olefines to form thermoplastics and to form elastomeric products, and which are also suitable for the polymerisation and copolymerisation of diolefines optionally with olefines.
SUMMARY OF THE INVENTION
It has now been found that particularly advantageous catalysts can be produced which comprise bridged &pgr;-complex compounds. particularly metallocene compounds, in which the bridge between the two &pgr; systems is produced by one, two or three reversible donor-acceptor bonds, and in which a coordinate bond or what is termed a dative bond is formed in each case between the donor atom and the acceptor atom, on which coordinate bond an ionic bond is superimposed, at least formally, and in which at least one of the donor or acceptor atoms is part of the associated &pgr; system in each case. In addition to the bridged state denoted by the arrow between D and A, the reversibility of the donor-acceptor bond also permits the unbridged state, in which, as a result of the rotational energy inherent in them, the two &pgr; systems can rotate in relation to each other, by 360 degrees of angle for example, without the integrity of the metal complex being lost. After a complete rotation, the donor-acceptor bond “snaps in” again. In the presence of a plurality of donors and/or acceptors, a “snapping-in” process such as this can even occur after less than 360 degrees of angle have been traversed. Metallocenes according to the present invention can therefore only be represented by a double arrow, and partial formulae (Ia) and (Ib) represent the inclusion of both these states.
Accordingly, the present invention relates to &pgr; complex compounds. and particularly metallocene compounds of formula
wherein
&pgr;I and &pgr;II represent &pgr; systems which bear charges which are different from each other or which are electrically neutral, and which can be singly- or doubly-condensed with unsaturated or saturated five- or six-membered rings,
D denotes a donor atom which is a substituent of &pgr;I or is part of the &pgr; system of &pgr;I, and which has at least one free electron pair available in its respective bonding state,
A denotes an acceptor atom which is a substituent of &pgr;II or is part of the &pgr; system of &pgr;II, and which has an electron pair vacancy in its respective bonding state,
wherein D and A are linked by a reversible coordinate bond in such a way that the donor group assumes a positive (partial) charge and the acceptor group assumes a negative (partial) charge, and wherein at least one of D and A is part of the associated &pgr; system in each case,
wherein D and A themselves may comprise substituents,
wherein each &pgr; system or each condensed-on ring system can contain one or more D or A entities, or D and A entities, and
wherein in &pgr;I and &pgr;II, in the non-condensed or in the condensed form, one to all of the H atoms of the &pgr; system, independently of each other, can be substituted by identical or different radicals from the group comprising a linear or branched C
1
-C
20
alkyl which can be substituted singly to completely by halogens, can be substituted singly to three-fold by phenyl or can be substituted singly to three-fold by vinyl; a C
6
-C
12
aryl, and a halogenoaryl comprising 6 to 12 C atoms; and said H atoms can also be singly- or doubly-substituted by D and A, so that the reversible coordinate D→A bond is formed (i) between D and A, which both constitute parts of the respective &pgr; system, or (ii) from the D or A part of the &pgr; system and the other substituent of the non-condensed &pgr; system or of the condensed-on ring system in each case, or (iii) both D and A are such substituents, wherein in the case of (iii) at least one additional D or A entity or both is (are) part of the &pgr; system or of the condensed-on ring system,
M represents a transition metal of subgroups III, IV, V or VI of the periodic table of the elements (Mendeleev), including the lanthanides and actinides,
X denotes an anion equivalent, and
n denotes the numbers zero, one, two, three or four depending on the charge of M and on those of &pgr; and &pgr;II.
DETAILED DESCRIPTION OF THE INVENTION
In
FIG. 1
, the structure of dimethylboranyl-cyclopentadienyl-tetramethylphospholyl-titanium tetrachloride is illustrated as an example (see the Examples).
&pgr; systems according to the invention comprise substituted and unsubstituted ethylene, allyl, pentadienyl, benzyl, butadiene, benzene, the cyclopentadienyl anion, and species which are formed by the replacement of at least one C atom by a hetero atom. Of the aforementioned species, cyclic species are preferred. The type of coordination of ligands (&pgr; systems) such as these to the metal can be of the &sgr; type or of the &pgr; type.
&pgr;-complex compounds of formula (I) in which the &pgr; systems are cyclic and aromatic (metallocenes), can be prepared, for example, either by the reaction of a compound each of formulae (II) and (III)
or by the reaction of a compound each of formulae (IV) and (V)
or by the reaction of a compound each of formulae (VI) and (VII)
with the separation of M′X in the presence or absence of an aprotic solvent, or by the reaction of a compound each of formulae (VIII) and (III)
or by the reaction of a compound each of formulae (IV) and (IX)
or by the reaction of a compound each of formulae (X) and (VII)
with the separation of E(R
1
R
2
R
3
)X and F(R
4
R
5
R
6
)X in the absence or presence of an aprotic solvent, wherein
&pgr;I, &pgr;II, D, A M, X and n have the meanings given above,
&pgr;III and &pgr;IV represent two different uncharged &pgr; systems with a structure corresponding to &pgr;I or &pgr;II,
M′ denotes a cation equivalent of an alkali or alkaline earth metal or Tl,
E and F, independently of each other, denote one of the elements Si, Ge or Sn, and
R
1
, R
2
, R
3
, R
4
, R
5
and R
6
, independently

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