JPH09309887A - Samarium complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new samarium complex useful for a production of another samarium complex useful as a catalyst for an olefin polymerization. SOLUTION: This samarium complex is a divalent samarium complex of the formula (ArO)SmI(THF)3 (ArO is a aryloxide ligand; THF is a tetrahydrofuran ligand). A complex having 2,6-di-tert-butyl-4-methylphenoxide anion as a ligand is a preferable one of the samarium complex. The samarium complex is obtained by reacting a well-known divalent samarium aryloxide complex (ArO)2 Sm(THF)3 with an equivalent amount of SmI2 . The complex is useful for a production of another samarium complex having the aryloxide ligand because of generating no disproportionation caused by a ligand rearrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel divalent samarium complex useful for producing a samarium complex useful as a catalyst for olefin polymerization.

[0002]

2. Description of the Related Art Divalent samarium which is a divalent lanthanoid
The complex of (Sm), conventionally, Cp ^{* -} (pentamethylcyclopentadienyl anion) or I ^- Studies about the complex having a plurality of identical ligand such has been promoted. Recently, as a lanthanoid complex having a novel ligand, a divalent lanthanoid complex (ArO) ₂ Ln having a bisaryloxide anion (ArO ⁻ ) as a ligand (Ln represents Sm or Yb,
O represents 2,6-di-tert-butyl-4-methylphenoxide anion), indicating that aryl oxide ligands are useful ligands for lanthanoid complexes. (Hou, Z., et al.,
J. Am. Chem. Soc., 117, pp.4421-4422, 1995; Yoshimu
ra, T., et al., Organometallics, 14, pp.4858-4864,
1995; Hou, Z., et al., J. Am. Chem. Soc., 116, p.
p.11169-11170, 1994). However, samarium complexes having two or more different ligands are difficult to synthesize due to ligand rearrangement and the like, and there are few reports so far.

For example, a divalent samarium amide complex Sm [N (S
iMe ₃ ) ₂ ] ₂ (THF) ₂ (Me: methyl group; THF: tetrahydrofuran ligand) is reacted with two equivalents of a hydroxyaryl compound such as 2,6-di-tert-butyl-4-methylphenol. , The corresponding divalent samarium aryl oxide complex (Ar
O) ₂ Sm (THF) ₃ is obtained, and when this complex is reacted with I ₂ , trivalent samarium iodide having an aryl oxide ligand: (ArO) ₂ Sm (THF) ₂ I It is known that it can be obtained (Chemical Society of Japan 1995 Spring Meeting, Abstract No. 3H5 / 43, Kyoto City).

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel samarium complex useful as an intermediate for producing a samarium complex useful for polymerization of olefins. More specifically, it is an object of the present invention to provide a samarium complex having two or more different ligands, which is stable without being disproportionated by rearrangement of the ligand. is there.

[0005]

The present inventors have made intensive efforts to solve the above-mentioned problems, and as a result, one aryloxide ligand and one iodine ligand were used as ligands of the divalent samarium complex. It has been found that the use of a combination of three tetrahydrofuran ligands can provide a stable divalent samarium complex having the above characteristics. The present invention has been completed based on the above findings.

That is, the present invention provides a divalent samarium complex represented by (ArO) SmI (THF) ₃ (where ArO represents an aryloxide ligand and THF represents a tetrahydrofuran ligand. The same applies to the above.). According to a preferred embodiment of the present invention, wherein the aryl oxide ligand is a 2,6-di-tert-butyl-4-methylphenoxide ligand or a 2,6-di-tert-butylphenoxide ligand. A complex is provided. According to another aspect of the present invention, there is provided the above divalent samarium complex used as a production intermediate of a samarium complex having an aryloxide ligand.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The complex of the present invention comprises (ArO) SmI (THF) ₃
Is a divalent samarium complex represented by ArO represents an aryl oxide ligand, and preferably a substituted phenoxide anion can be used. As the substituted phenoxide anion, those obtained by substituting one or more, preferably two or three alkyl groups on a benzene ring can be used. When it has two or more alkyl groups on the benzene ring, these alkyl groups may be the same or different, and two of these alkyl groups are respectively in the 2-position and the 6-position ( (The carbon atom substituted by the oxide group in the benzene ring of phenoxide is replaced with 1-position) to form a 2,6-dialkyl-substituted phenoxide anion.

The alkyl group to be substituted at the 2- and 6-positions on the benzene ring is preferably a sterically bulky C ₃ group such as an isopropyl group, a tert-butyl group or a neopentyl group from the viewpoint of the stability of the complex. it is preferred to use -C ₆ alkyl group. For example, 2,6-di-tert-butylphenoxide anion, 2,6-diisopropylphenoxide anion, 2,6-dineopentylphenoxide anion, 2-tert-butyl-6
-Isopropylphenoxide anion, 2-tert-butyl
-6-neopentylphenoxide anion or 2-isopropyl-6-neopentylphenoxide anion can be used. Of these, a phenoxide anion in which both the 2- and 6-positions of the benzene ring are substituted with a tert-butyl group (2,6-di-tert-butylphenoxide anion) is particularly preferred.

When the benzene ring of these 2,6-dialkyl-substituted phenoxide anions further has one or more, preferably one, alkyl group, the alkyl group may be C ₁ -C ₄ An alkyl group is preferable, and the substitution position of the alkyl group is preferably the 4-position. For example, C ₁ -C ₄ such as a methyl group or an ethyl group at the 4-position of the benzene ring of a 2,6-dialkyl-substituted phenoxide anion
A complex having a phenoxide anion into which an alkyl group has been introduced as a ligand is preferable from the viewpoint of solubility and the like.
More specifically, the ligand is 2,6-di-tert-butyl-4-
Complexes having a methylphenoxide anion are a particularly preferred embodiment of the present invention.

[0010] The complex of the present invention is a known divalent samarium aryl oxide complex (ArO) ₂ Sm (THF) ₃ (wherein ArO and TH
F is as described above) with an equivalent amount of SmI ₂ to produce the compound in good yield. (ArO) ₂ Sm (THF) ₃ used as a raw material can be obtained by a known method (for example,
rka, A. et al., The Chemical Society of Japan 1995 Annual Meeting, Abstract No. 3H
5/43, Kyoto, 1995) by reacting a divalent samarium amide complex Sm [N (SiMe ₃ ) ₂ ] ₂ (THF) ₂ (SiMe ₃ : trimethylsilyl group) with two equivalents of a hydroxyaryl compound. It can be easily manufactured. As the hydroxyaryl compound, a compound corresponding to a desired aryl oxide ligand may be used, for example, 2,6-di-ter
When the t-butyl-4-methylphenoxide anion is introduced as a ligand,
2,6-di-tert-butyl-4-methylphenol may be used.

The divalent samarium complex of the present invention can be stably isolated as a monomer type complex or a dimer type complex, generally a monomer type complex, and causes disproportionation due to rearrangement of ligands. There is no feature.
The complex of the present invention is expected to be usable as a catalyst for various organic reactions, and can also be used as a raw material for producing another divalent samarium complex having an aryloxide ligand. For example, by reacting the complex of the present invention with Cp ^* -K (potassium pentamethylcyclopentadienide) in the presence of HMPA (hexamethylphosphoramide), a Cp ^* ligand and an aryloxide ligand are formed. (For example, Cp ^* (ArO) Sm (HMP
A) ₂ ) can be manufactured.

[0012]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but the scope of the present invention is not limited to these Examples. Example 1 Preparation of the Complex of the Invention Sm [N (SiMe ₃ ) ₂ ] ₂ (THF) ₂ (4.44 g, 7.21 mmol) was dissolved in tetrahydrofuran (50 ml) and 2,6 dissolved in 20 ml of tetrahydrofuran. -Ditertiary butyl-4-methylphenol (3.18 g, 14.42 mmol) was added, and the mixture was stirred at room temperature for 2 hours. The residue obtained by distilling off the solvent under reduced pressure was washed with hexane, and recrystallized from tetrahydrofuran / toluene to form a phenoxide-samarium complex (ArO) ₂ Sm (THF) ₃ (A
rO: 2,6-di-tert-butyl-4-methylphenoxide ligand) was obtained as dark brown crystals (4.81 g, 5.97 mmol, yield)
83%). ¹ H-NMR (C ₆ D ₆ , 22 ° C) δ: 9.15 (brs, 12H, THF), 4.20
(brs, 12H, THF), -0.10 (brs, 36H, tert-Bu), -0.95 (b
rs, 4H, C ₆ H ₂ ), -1.90 (brs, 6H, Me) Anal.Calcd. for C ₄₂ H ₇₀ O ₅ Sm: C, 62.67%; H, 8.76%.
Found: C, 62.30%, H, 8.81%.

The above complex (ArO) ₂ Sm (THF) ₃ (0.81 g, 1 m
mol) was dissolved in 5 ml of tetrahydrofuran, and SmI ₂
(10 ml, 1 mmol) in 0.1 M tetrahydrofuran solution and stirred at room temperature for 4 hours. Ether was added to the concentrated solution from which the solvent was partially distilled off under reduced pressure, and the complex (ArO) SmI (T
HF) ₃ (ArO: 2,6-di-tert-butyl-4-methylphenoxide ligand) was precipitated as black crystals (0.91 g). When the crystals were dried under reduced pressure, it was confirmed that two tetrahydrofuran molecules were lost per complex molecule.
(80% yield with missing THF molecules). ¹ H-NMR (C ₆ D ₆ , 22 ° C) δ: 4.40 (brs), 1.53 (brs), -3.5
~ 0.5 (very broad) Anal. Calcd. For C ₁₉ H ₃₁ O ₂ ISm [ ₂ per molecule of complex
Of THF molecules lost: (ArO) Sm (μ-I) (THF)]:
C, 40.12%; H, 5.49%. Found: C, 39.50%, H, 5.79%.

Example 2: Reference example (Production of samarium complex using complex of the present invention) The above (ArO) SmI (THF) (0.57 g, 1 mmol) was dissolved in tetrahydrofuran, and pentamethylcyclopentadieno. Potassium (0.18 g, 1 mmol) was added to a solution of tetrahydrofuran. After stirring the dark brown reaction solution overnight, it was filtered and the mother liquor was concentrated under reduced pressure to give a dark brown residue. This residue was washed with toluene, dissolved in tetrahydrofuran, and further added with hexamethylphosphoramide (0.35 ml, 2 mmol). The reaction solution was partially concentrated under reduced pressure, and crystals precipitated by adding ether were collected by filtration, and the samarium complex Cp ^* (Ar
O) Sm (HMPA) ₂ (ArO: 2,6-ditert-butyl-4-methylphenoxide ligand) was obtained as brown columnar crystals. ¹ H-NMR (C ₆ D ₆ , 22 ° C.) δ: 5.26 (s, 15 H, C ₅ Me ₅ ), 4.20
(brs, 36H, NMe), 2.76 (s, 18H, tert-Bu), 2.24 (s, 2
H, C ₆ H ₂ ), 0.42 (S, 3H, Me) Anal.Calcd. For C ₃₇ H ₇₄ N ₆ O ₃ P ₂ Sm: C, 51.47; H, 8.6
4; N, 9.73. Found: C, 51.10; H, 8.73; N, 9.91

[0015]

The samarium complex of the present invention has a feature that disproportionation due to ligand rearrangement is unlikely to occur, and is useful for producing another samarium complex having an aryloxide ligand. .

Continuation of the front page (72) Inventor Kei Yoshimura 10-3, Otohmachi, Kanazawa-ku, Yokohama-shi, Kanagawa

Claims (3)

[Claims] 1. A divalent samarium complex represented by (ArO) SmI (THF) ₃ (where ArO represents an aryloxide ligand and THF represents a tetrahydrofuran ligand). 2. The method according to claim 2, wherein the aryl oxide ligand is 2,6-di-tert-
Butyl-4-methylphenoxide ligand or 2,6-di-tert-
The complex according to claim 1, which is a butylphenoxide ligand. 3. The complex according to claim 1, which is used as an intermediate for producing a samarium complex having an aryloxide ligand.