JPH0730104B2 - Ruthenium-phosphine complex - Google Patents

Description

TECHNICAL FIELD The present invention relates to a complex of a specific phosphine compound and ruthenium.

2. Description of the Related Art Among complexes in which a chiral tertiary phosphine is coordinated with a metal element such as rhodium, ruthenium, or palladium, many have excellent performance as a catalyst for asymmetric synthesis.

Chemistry Review 32 “Chemistry of Organometallic Complexes” (edited by the Chemical Society of Japan, published in 1982) As listed on pages 237 to 238, phosphine compounds having a special structure are used to enhance the catalytic performance. Many have been developed so far.

2,2'-Bis (diphenylphosphino) -1,1'-binaphthyl (this may be abbreviated as BINAP) is one of the excellent ones (JP-A-55-61937).
(See the official gazette). In addition, a rhodium complex of 2,2'-bis (di-p-tolylphosphino) -1,1'-binaphthyl (in the following description, this may be abbreviated as p-TBINAP) (JP-A-60) -199898) and ruthenium complex of BINAP and p-TBINAP (see Japanese Patent Laid-Open No. 61-63690), good results for asymmetric hydrogenation, asymmetric isomerization and asymmetric dehydrogenation. Has been reported to have been carried out with.

Problems to be Solved by the Invention As described above, many transition metal-phosphine complexes in which a special phosphine compound is coordinated to enhance the performance as an asymmetric synthesis catalyst have been developed, but the selectivity and the conversion rate However, there is still nothing satisfactory in terms of sustainability and the like, and the development of a new transition metal-phosphine complex that dramatically improves the conventional catalyst performance has been desired.

Means for Solving the Problems The inventors of the present invention conducted extensive research aiming at the development of a transition metal-phosphine complex that imparts excellent catalytic performance, and
As a result of studying BINAP derivatives, ruthenium-phosphine complexes in which a phosphine compound having a methoxy group introduced at the 4,4 ′ position of a phenyl group was coordinated were found to have no substituents such as BINAP, p-TBINAP and 2,2 ′. -Bis [di- (pt-
Butylphenyl) phosphino] -1,1′-binaphthyl (in the following description, this is referred to as pt-butyl BINAP
Sometimes abbreviated. The present invention has been completed by finding that the conversion rate in asymmetric synthesis is remarkably increased as compared with a transition metal-phosphine complex in which a phosphine compound such as) is coordinated.

That is, the present invention is The novel phosphine compound represented by the formula 2,2'-bis [di- (p-methoxyphenyl) phosphino] -1,1'-binaphthyl (in the following description, this is p-methoxy
Sometimes abbreviated as BINAP. ) Coordinated ruthenium-phosphine complex.

(Production Method) The synthesis of the phosphine compound which is the ligand of the complex of the present invention is carried out according to the following formula.

Phosphorus oxychloride (11) and benzene are cooled with ice, and a solution of diethylamine (2) in benzene is added dropwise to react with each other. The produced crystals are filtered and washed with benzene. The obtained filtrate was concentrated and the residue was distilled to obtain N, N-
Diethylamido dichlorophosphate (3) is obtained.

On the other hand, Grignard reagent (5) was prepared from p-bromoanisole (4) in tetrahydrofuran, and N, N-diethylamidodichlorophosphate (3) was added to this.
Tetrahydrofuran solution of
(P-Methoxyphenyl) phosphinic acid (6) is obtained.
Thionyl chloride was added to di- (p-methoxyphenyl) phosphinic acid to react, the excess thionyl chloride was removed, and recrystallized with a mixed solution of benzene-hexane to di- (p-methoxyphenyl) phosphonyl chloride (7). To get

2,2'-Dibromo-1,1'-binaphthyl (8) is
According to the method of Noyori et al. Described in JP-A-61-54036, triphenylphosphine is used as a reaction aid, and bromine and
It is synthesized by reacting 1,1'-bi-2-naphthol.
The 2,2′-dibromo-1,1′-binaphthyl (8) is treated with magnesium to prepare a Grignard reagent (9),
The previously synthesized di- (p-methoxyphenyl) phosphonyl chloride was added to and reacted with 2,2'-bis [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl (10 ) Is synthesized.

Brunel's "Angewante Chemie International English Version" (H. Brunner: Angw.Chem.Int.Edt.Engl., 18 , 620, (1
979)), and an optically active substance is obtained by a method of optical resolution using dibenzoyl tartaric acid.
The optically active 2,2'-bis- [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl obtained was obtained by a known method [that is, "Hemische Berichte" Chem. Be.
r., 98 , 171, (1965)], trichlorosilane (HS
reduced with LiCl _3), a phosphine compound of the present invention 2,2'-bis - obtaining [di (p- methoxyphenyl) phosphino] -1,1'-binaphthyl (12).

The p-methoxy BINAP obtained as described above forms a complex with ruthenium.

The ruthenium-phosphine complex of the present invention has the following general formula (1) (Ru) _x (L) _y (J) (Q) _z (1) (where L in the formula is 2,2'-bis (di ( p-methoxyphenyl) phosphino) -1,1′-binaphthyl, J represents a hydrogen atom or NEt _3, and when J is a hydrogen atom, Q represents a halogen atom, ClO ₄ , BPh ₄ , or PF ₆ . , X = 1, y =
2 represents z = 1. When J is NEt ₃ , Q represents a halogen atom and represents x = 2, y = 2, and z = 4. ) Or a ruthenium-phosphine complex represented by the following general formula (2) Ru (L) (A) ₂ (2) (wherein L is 2,2′-bis (di (p-methoxyphenyl)) represents phosphino) -1,1'-binaphthyl, a is _{OCOCH3, OCOBu-t, OCOC 6} H 6, OCOCF 3, ClO 4, PF 6
Or represents BF ₄ . ] It is a ruthenium-phosphine complex represented by these.

[Rh (COD) Cl ₂ ] and COD were dissolved in methylene chloride, AgClO ₄ , AgBF ₄ or AgPF ₆ was added thereto, the mixture was stirred for 1 hour, the silver salt was filtered, and the solution was concentrated. [Rh (COD) ₂ ] X is synthesized. [Rh (NBD) ₂ ] X is similarly synthesized. By adding p-methoxy-BINAP to this complex, stirring in methylene chloride for 1 hour, and concentrating the solution, [Rh (NBD) (p-methoxy BINAP)]
X or [Rh (COD) (p-methoxy BINAP)] X is synthesized.

[Rh (p-methoxy BINAP) ₂ ] X (where X in the formula is the same as above) is synthesized by the method described in JP-A-60-61587.

[Rh (COD) (p-
Methoxy BINAP)] X or [Rh (NBD) (p-methoxy
BINAP)] X, another molecule of p-methoxy BINAP is added, and hydrogenation is carried out in tetrahydrofuran for about 3 hours under normal pressure, and the solution is concentrated to give [Rh (p-methoxy BINAP
NAP) ₂ ] X complex is synthesized.

Ru ₂ Cl ₄ (p-methoxy BINAP) ₂ Et ₃ N (However, Et in the formula
₃ N represents triethylamine) and RuHCl (p-methoxyBINAP) ₂ are synthesized by the method described in JP-A-61-63690.

[Ru (COD) Cl ₂ ] _n , p-methoxy BINAP and triethylamine were refluxed in toluene for 6 to 10 hours, and after completion of the reaction, the solution was concentrated to remove Ru ₂ Cl ₄ (p-methoxy B).
INAP) ₂ NEt ₃ is synthesized.

Further, [Rh (COD) Cl ₂ ] _n , p-methoxy BINAP and triethylamine were refluxed in ethanol for 12 hours, and the precipitated crystals were separated by filtration and dried to obtain RuHCl (p-methoxyBI).
NAP) ₂ is obtained.

[Ru (p-methoxyBINAP)] X ₂ and [RuH (p-methoxyBINAP)]
AP) ₂ ] X (where X is the same as defined above) means the presence of an aqueous solution of triethylbenzylammonium bromide in the presence of each salt in methylene chloride under nitrogen substitution in a Schlenk tube. Under each Ru ₂ Cl ₄ (p-methoxy BIN
AP) ₂ Et ₃ N and RuHCl (p-methoxyBINAP) ₂ can be easily synthesized by the method described in the specification of Japanese Patent Application No. 61-184651.

Ru ₂ Cl ₄ (p-methoxy BINAP) ₂ NEt ₃ or RuHCl (p-methoxy BINAP) ₂ and NaClO ₄ , NaBF ₄ or KPF ₆ in the presence of a phase transfer catalyst such as triethylbenzylammonium bromide and methylene chloride-H. Stir for 12 hours with ₂ O system,
After completion of the reaction, an extraction operation is performed and the organic layer is concentrated,
[Ru (p-methoxy BINAP)] X ₂ or [RuH (p-methoxy BINAP) ₂ ] X is synthesized.

(However, R in the formula represents a methyl group, a t-butyl group, a phenyl group or a trifluoromethyl group.)
According to the method described in the specification of No. 8888, R is a methyl group,
In the case of t-butyl group or phenyl group, carboxylic acid salts corresponding to Ru ₂ Cl ₄ (p-methoxyBINAP) ₂ Et ₃ N, that is, sodium acetate, sodium 2,2-dimethylpropionate and sodium benzoate are used. Each was placed in a Schlenk tube, and after performing nitrogen substitution, t-butanol was added and the mixture was heated under reflux to cause a reaction. After completion of the reaction, t-butanol was distilled off under reduced pressure of 20 mmHg to dryness, followed by extraction with ethyl ether, evaporation of ethyl ether to dryness, and further extraction of the obtained solid with ethanol, It is obtained by concentrating and drying this extract.

When R is a trifluoromethyl group, Ru (p-methoxyBINAP) (O ₂ CCH ₃ ) ₂ obtained above is put into a Schlenk tube, nitrogen substitution is performed, and deoxygenated methylene chloride is added. Melt. Trifluoroacetic acid is added to this to react, and the mixture is concentrated to dryness to obtain a crude complex. This complex is dissolved in toluene, hexane is added, the mixture is allowed to stand at room temperature overnight, the precipitated solid is collected by filtration, and dried under reduced pressure for 10 hours to obtain the complex.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, Use Examples, Reference Examples and Comparative Examples.

The melting point was measured using a micro melting point measuring device manufactured by Yanagimoto Seisakusho. Nuclear magnetic resonance spectra of ¹ H NMR using tetramethylcitane as an internal standard and ³¹ P NMR using 85% phosphoric acid as an internal standard were manufactured by Bruker AM-400 type instrument (4
00 MHz). DIP-4 made by JASCO
It measured using the mold device.

Reference Example 1 Synthesis of N, N-diethylamide dichlorophosphate (3) Phosphorus oxychloride 365 g (2.4 mol) and benzene 650 ml were cooled in an ice bath, and diethylamine 359 g (4.9 mol) was added thereto.
Was added dropwise to a solution of 350 ml of benzene over 70 minutes,
Then, stirring was continued for 20 minutes at room temperature. The crystals formed were filtered off, washed with 600 ml of benzene and the filtrate was concentrated,
The residue was distilled to obtain 392 g of N, N-diethylamide dichlorophosphate (87% of theoretical yield). The boiling point of this substance is
It was 105-108 ° C / 22 mmHg.

Reference Example 2 Synthesis of di- (p-methoxyphenyl) phosphinic acid (6) 66 g (2.7 mol) of magnesium, 500 ml of tetrahydrofuran and 1 g of iodine were placed in a 5-liter 4-necked flask, and p-bromoanisole (manufactured by Junsei Kagaku Co., Ltd.). 504g (2.7mol)
700 ml of tetrahydrofuran solution of was added dropwise over 3.5 hours under reflux. After the dropping was completed, the reflux was continued for 1.5 hours. Next, diethylamido dichlorophosphate obtained in Example 1
A solution of 255 g (1.3 mol) of 200 ml of tetrahydrofuran was added dropwise under reflux over 1 hour. After the dropping, reflux was continued for 2 hours to complete the reaction. The reaction solution was cooled, and 200 g of ammonium chloride, water 1 and 0.5 kg of ice were added thereto, and the mixture was stirred to separate the layers. 300 ml of tetrahydrofuran was added to the aqueous layer for extraction. Combine the tetrahydrofuran in the oil layer and add it to concentrated hydrochloric acid.
2 l was added, and the mixture was heated with stirring at 80 ° C. for 3 to 4 hours. Ice water 1 was added and cooled, and the precipitated crystals were filtered and washed with 500 ml of water to obtain 493 g of crude phosphinic acid. A solution of 70 g of caustic soda dissolved in 2.8 l of water and 7 g of activated carbon were added to the obtained crude phosphinic acid, and the mixture was dissolved and the insoluble matter was filtered off. The filtrate was extracted twice with 500 ml of benzene to remove soluble substances. The remaining aqueous layer was neutralized by adding a solution of 35% hydrochloric acid 185 g in 200 ml of water to pH 1.
And The crystals formed were filtered off, washed with 2 l of water and dried to obtain 261 g of di- (p-methoxyphenyl) phosphinic acid. The yield is 70% of the theoretical yield, and the melting point is 181-1.
It was 83 ° C.

Reference Example 3 Synthesis of di- (p-methoxyphenyl) phosphonyl chloride (7) To 119 g (428 mmol) of di- (p-methoxyphenyl) phosphinic acid obtained in Example 2 was added 1.2 l of thionyl chloride (16.
45 mol) was added, and the mixture was heated and stirred at 80 to 90 ° C. for 30 minutes to cause a reaction. Thionyl chloride was distilled off under reduced pressure, and the residue was recrystallized from a benzene-hexane mixture to obtain 122.8 g (97% of theoretical yield) of white crystals of di- (p-methoxyphenyl) phosphonyl chloride. ¹ HNMR δppm 3.92 (S, 6H) 7.03 (d, 2H, J = 9Hz) 7.06 (d, 2H, J = 9Hz) 7.78 (d, 2H, J = 9Hz) 7.95 (d, 2H, J = 9Hz) Reference example 4 Synthesis of 2,2′-bis- [di- (p-methoxyphenyl) phosphoryl] -1,1′-binaphthyl (10) Magnesium 6.30 g (0.26 mol), tetrahydrofuran 100 ml, toluene 100 ml, dibromo in flask 1 Add 0.1 ml of ethane and 0.1 g of iodine, bring to 70-80 ° C in an oil bath, and then 41.2 g of 2,2'-dibromo-1,1'-binaphthyl (8)
(0.1 mol) and 200 ml of toluene were added dropwise over 5 hours. After the completion of dropping, 74.10 g (0.25 mol) of di- (p-methoxyphenyl) phosphoryl chloride (7) and toluene
50 ml was added dropwise at 40 to 45 ° C over 1 hour, and stirring was continued for 1 hour. After the reaction, 200 ml of water was added and the mixture was extracted 3 times with 100 ml of dichloroethane. The solvent was concentrated to obtain 71 g of a crude product. Purified by silica gel column chromatography using Kieselgel 60 (70-230 mesh) manufactured by Merck (eluting solvent was benzene) and recrystallized from carbon tetrachloride to obtain 2,2'-bis- [di-]. (P-Methoxyphenyl) phosphoryl] -1,1′-bunaphtyl 35.0 g
(37.7% of theoretical yield) was obtained. ¹ HNMR (CDCl ₃ ) δppm 3.73 (S.6H) 3.77 (S.6H) 6.60-7.80 (m.28H) Reference Example 5 (+)-2,2'-bis [di- (p-methoxyphenyl)]
Synthesis of phosphoryl] -1,1'-binaphthyl (10) 17.0 g (18.3 mmol) of 2,2'-bis [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl (10) −) 6.9 g of dibenzoyl tartaric acid (Tokyo Kasei)
(18.3 mmol) was added to chloroform 65 ml and ethyl acetate 45
The crystals were dissolved in a mixed solution with 0 ml and recrystallized to obtain 7.4 g of primary crystals. Add 30 ml of chloroform and 200 ml of ethyl acetate.
The crystals were recrystallized with a mixed solution of and to obtain 5.2 g of secondary crystals.

Primary crystal ▲ [α] ²⁵ _D ▼ = + 24.0 ° (C3.25, CHCl ₃ ) Secondary crystal ▲ [α] ²⁵ _D ▼ = + 25.98 ° (C3.03, CHCl ₃ ) Secondary crystal 5.2 Hydrolyze g with 10% caustic soda solution,
The reaction mixture was extracted with 20 ml of chloroform three times to obtain optically active 2,
3.6 g of 2'-bis [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl was obtained.

▲ [α] ²⁵ _D ▼ = + 108.95 ° (C3.43, CHCl ₃ ) Reference Example 6 (+)-2,2′-bis [di- (p-methoxyphenyl)
Synthesis of phosphino] -1,1'-binaphthyl (I) The optically active (+)-2,2'-bis [di- (p-methoxyphenyl) obtained in Example 5 was placed in a 500 ml flask.
Phosphoryl] -1,1'-bunaphthyl (3.6 g, 4.65 mmol), xylene (200 ml), and triethylamine (9.4 g, 93 mmol) were added and stirred to dissolve.

12.6 g (93 mmol) of trichlorosilane was added to the solution.
Add dropwise over -30 minutes, react at 100 ℃ for 1 hour, 120 ℃ for 1 hour, 140 ℃ for 1 hour, then cool to room temperature and add 30 ml of 30% caustic soda solution at 50-60 ℃. 30
Stir for minutes. The aqueous layer was separated and removed from the mixture, and the xylene layer was concentrated.

Degassed methanol was added to the obtained residue and recrystallized to give (+)-2,2'bis [di- (p-methoxyphenyl) phosphino] -1,1'-binaphthyl 2.8 g (theoretical yield). 81.2
%) Was obtained.

▲ [α] ²⁵ _D ▼ ＝ ＋ 115.75 ° (C3.67, benzene) ¹ HNMR (CDCl ₃ ) δppm 3.716 (S, 6H) 3.719 (S, 6H) 6.60-7.85 (n.28H) Elemental analysis C _{48 31} P NMR (CDCl ₃ ) δppm −17.45 (S) as H ₄₀ O ₄ P ₂ Reference Example 7 (−)-2,2′-bis [di- (p-methoxyphenyl)
Synthesis of phosphoryl] -1,1'-binaphthyl 2,2'-bis [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl 20 g (2
(+)-Dibenzoyltartaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) (9.71 g, 25.8 mmol) was added to (5.8 mmol) and recrystallized to 10.2 g.
Was obtained. The resulting crystals were hydrolyzed with a 10% aqueous sodium hydroxide solution to give (-)-2,2'-bis [di- (p-methoxyphenyl) phosphoryl] -1,1'-binaphthyl (6.2 g).
(84% of theoretical yield) was obtained.

▲ [α] ²⁵ _D ▼ = + 169.6 ° (C 0.5, tetrahydrofuran) Reference Example 8 (−)-2,2′-bis [di- (p-methoxyphenyl)
Synthesis of Phosphino] -1,1'-binaphthyl (-)-2,2'-bis [di- (p-
Methoxyphenyl) phosphoryl] -1,1'-binaphthyl
6.2 g was reduced in the same manner as in Example 6 to give (−)-2,2′-bis [di- (p-methoxyphenyl) phosphino] -1,
4.8 g (81% of theoretical yield) of 1'-binaphthyl was obtained.

▲ [α] ²⁵ _D ▼ = -109.2 ° (C0.5, benzene) Example 1 Preparation of Ru ₂ Cl ₄ ((-)-p-methoxyBINAP) ₂ Et ₃ N Ruthenium cyclooctadiene chloride ([RuCl ₂ (CO
D)] _n ) 0.36 g (1.3 mmol) and (-)-2,2'-bis [di- (p-methoxyphenyl) obtained in Reference Example 8
Phosphino] -1,1'-binaphthyl ((-)-p-methoxy BINAP) 1 g (1.35 mmol) and triethylamine
0.8 ml was added to the reactor under a stream of nitrogen in 35 ml toluene. After heating and refluxing for 10 hours, the solvent was distilled off under reduced pressure after the reaction. Methylene chloride was added to the remaining crystals to dissolve them, and the crystals were filtered over Celite, and the filtrate was concentrated to dryness to give di {2,
2'-bis [di (p-methoxyphenyl) phosphino]
-1,1'-Binaphtyl} tetrachlorodilthenium triethylamine (Ru ₂ Cl ₄ ((-)-p-methoxy BINAP) ₂ Et ₃ N) 1.20 g
A dark brown solid (95% of theoretical yield) was obtained.

Elemental analysis As C ₁₀₂ H ₉₅ Cl ₄ N ₁ O ₈ P ₄ Ru ₂ , ³¹ PNMR δppm 48.43 (S) 48.67 (S) Example 2 Preparation of Ru ((−)-p-methoxy BINAP) (OAC) ₂ Ru ₂ Cl ₄ ((−)-p-methoxy BINA) prepared in Example 1.
P) ₂ Et ₃ N 1 g (0.5 mmol) and sodium acetate 0.8 g (10 mmol) were put into a 100 ml Schlenk tube, and after sufficiently replacing the nitrogen, 50 ml of t-butanol was added, and the mixture was heated under reflux for 12 hours for reaction. Let

After completion of the reaction, t-butanol was distilled off to dryness, the residue was dissolved in 20 ml of methylene chloride, and the mixture was filtered on Celite. The methylene chloride in the filtrate was evaporated to dryness, the obtained solid was further dissolved in 20 ml of ethanol, and the insoluble matter was filtered off on Celite.

The filtrate was concentrated to dryness to give 2,2'-bis [di- (p-methoxyphenyl) phosphino] -1,1'-binaphthyl ruthenium diacetate. 0.8 g (83% of theoretical yield) of yellow solid was obtained.

Elemental analysis is as C ₅₂ H ₄₆ O ₈ P ₂ Ru Met. ³¹ PNMR δppm: 62.07 (s) Application example Synthesis of (+)-6-methoxy-α-methyl-2-naphthaleneacetic acid (naproxen) 6-methoxy-α-methylene-2-naphthaleneacetic acid was added to an argon-substituted 100 ml autoclave. (JP-A-54-16
262 mg (1.16 mmol) (synthesized according to the description of Japanese Patent No. 3561) and 20 ml of methanol were added, and prepared in Use Example 2. Add 4.3 mg (0.0045 mmol) of hydrogen, hydrogen pressure 95 kg / cm ² , 1
Hydrogenated at 8 ° C for 12 hours. After the reaction, the solvent methanol was distilled off to obtain (+)-6-methoxy-α'-methyl-
239 mg of 2-naphthalene acetic acid (87.4% of theoretical yield) was obtained. The optical rotation of the material thus obtained was.

▲ [α] ²⁵ _D ▼ = + 47.6 ° (C 1.01, CHCl ₃ ) The optical purity of this substance is 72% calculated from the optical rotation of the pure substance ▲ [α] ²⁵ _D ▼ = + 66.1 °. And the melting point was 154-155 ° C., ¹ HNMR: δppm: 1.57 (d, 3H) 3.68 (q, 1H) 3.90 (s, 3H) 7.07-7.87 (m, 6H) 10.83 (s, 1H).

EFFECTS OF THE INVENTION The ruthenium-phosphine complex of the present invention is a very excellent asymmetric hydrogenation catalyst, and an optically active compound can be industrially produced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidenori Unbayashi 1-4-39 Nakakaigan, Chigasaki City, Kanagawa Prefecture (72) Inventor Susumu Akutagawa 1081-22 Shinohara-cho, Kohoku-ku, Yokohama City, Kanagawa Prefecture (72) Inventor Kitamura Masato 2-4 Harusato-cho, Chikusa-ku, Nagoya-shi, Aichi (72) Inventor Katsunori Nagai 3-6-6 Yasui, Kita-ku, Nagoya-shi, Aichi (56) References Japanese Patent Laid-Open No. 64-9952 (JP, A)

Claims (1)

[Claims] 1. The following general formula (1) (Ru) _x (L) _y (J) _w (Q) _z (1) (where L is 2,2'-bis (di (p- Methoxyphenyl) phosphino) -1,1′-binaphthyl, J represents a hydrogen atom or NEt ₃ , w represents 0 or 1, and when w is 1 and J is a hydrogen atom, Q is a halogen atom. ,
Represents ClO ₄ , BPh ₄ or PF ₆ , where x = 1, y = 2, z =
In the case where w is 1 and J is NEt ₃ , Q represents a halogen atom, x = 2, y = 2, z = 4, and when w is 0, Q is OCOCH ₃ , OCOBu- t, OCOC ₆ H ₅ , OCOCF ₃ , ClO ₄ , PF ₆ or BF ₄ , where x = 1 and y =
1 and z = 2. ) A ruthenium-phosphine complex represented by