DE19946475A1 - Binuclear rhodium complexes with bidentate phosphite, arsenite or antimonite ligands, useful as catalysts, especially for the production of aldehyde by hydroformylation of olefin - Google Patents

Abstract

Binuclear rhodium complexes with bidentate phosphite, arsenite or antimonite chelating ligands. Binuclear rhodium complexes of formula (I) with bidentate chelating ligands of formula (II): Q--Q' = a bidentate ligand (2); Q<1>, Q<2> = phosphorus, arsenic or antimony; R<0> = a bivalent organic group; Z<1>-Z<4> = monovalent organic groups, or Z<1> plus Z<2> and/or Z<3> plus Z<4> may combine to form bivalent groups; x, z = 0-2; y = 0-4. Independent claims are also included for: (a) a process for the production of aldehydes by: (i) reaction of olefinic compounds with hydrogen and carbon monoxide in presence of a complex catalyst containing at least Rh and an organic phosphite; (ii) separation of the reaction product into aldehyde and catalyst liquid; and (iii) recycling catalyst liquid to the reaction zone, in which at least one of these stages is carried out in presence of a binuclear Rh complex (I) as defined; and (b) a process for the production of alcohols by direct hydrogenation of aldehydes obtained from process (a) or by dimerization of these aldehydes followed by hydrogenation.

Description

Field of application of the invention

The invention relates to a new binuclear rhodium complex bidentate chelate ligand. The complex according to the invention is special suitable for use in a process in which a rhodium Complex catalyst is used, for example in a hydroformyly tion reaction (oxosynthesis reaction), and it can decompose the ligan suppress and the resulting deactivation of the catalyst.

State of the art

A rhodium compound is known to have a catalytic activity for a hydroformylation reaction, a hydrosilylation reaction, a Hy drocyanation reaction, a hydrogenation reaction or the like. The rhodium Compound is widely used, particularly as a catalyst for a hydroformylation reaction, and it is already known that the activi act and the selectivity of the hydroformylation reaction can be improved  can be modified by a ligand, for example a triva lente phosphorus compound. Accordingly, different Analy sen in a rhodium complex, which is a composition of example wise carbon monoxide, hydrogen and a trivalent phosphorus compound comprises carried out with respect to the hydroformylation reaction. Among the Rhodium complexes are the mononuclear (mononuclear) rhodium Complexes already known which are believed to be active Are complexes for the hydroformylation reaction. In general it is about these complexes are rhodium complexes with the formal oxidati number of monovalence and a rhodium-hydrogen bond. Moreover are already various multinuclear (multinuclear) complexes, for example wise binuclear complexes, trinuclear complexes, tetranuclear complexes and hexanuclear complexes. In general, it is rhodium complexes with the formal oxidation number of 0-valence and ei A rhodium-rhodium bond. Among these are regarding binucleare Complexes already known to be a coordinating binuclear rhodium complex attached monodentate triphenylphosphine as described in "J. Chem. Soc." (A) (1968), pp. 2660-2672, by J. Wilkinson et al. described a binuclear Rhodium complex with coordinated monodentate triisopropyl phosphite as described in "J. Am. Chem. Soc." (1981), pp. 5517-5522, by J.M. Williams et al. described, and a binuclear rhodium complex with coordinativ ange stored bidentate phosphine, as in "Organometallics" (1992), pp. 2767-2774, by M. Cowie et al. described.

In addition, to improve the activity and selectivity of the Hy droformylation reaction already different trivalent phosphorus ligands designed. Such trivalent phosphorus compounds are already ver different phosphite compounds known. In addition to simple toothing Phosphites such as trialkyl phosphites or triaryl phosphites have already been developed Polyphosphites with a large number of coordinating phosphorus atoms in them ren proposed molecules. It has also become a significant verb of a bidentate phosphite compound from bidentate chelate  Type, which has a high activity and a particularly good selectivity, he aims. For example, in JP-A-62-116587 and JP-A-6-166694, one is two toothy phosphite compound described in which one of the two phosphite Groups has a cyclic structure, in JP-A-62-116535, JP-A-6-184036 and JP-A-6-199728 describes a bidentate phosphite compound in both of which have phosphite groups having cyclic structures, and in JP-A-5-178779 describes a bidentate phosphite compound in which none of the is cyclized both phosphite groups.

As indicated above, the meaning of bidentate phosphite is in the Hydroformylation reaction widely recognized. Among the rhodium Complexes that are composed of, for example, carbon monoxide, Have hydrogen and a trivalent phosphorus compound is in be pull on the hydroformylation reaction, however, only a tetranuclear com plex as a multinuclear rhodium complex with the formal oxidation number the 0-valence and with coordinated bidentate phosphite knows. The complex mentioned is a tetranuclear rhodium complex in which bidentate phosphites are coordinated so that they are two rhodium Network atoms with each other, as in "Inorganica Chimica Acta" (1996), pp. 125-136, by W. L. Gladfelter et al. described. On the other hand, there is in relation to a 0-valent binuclear rhodium complex with attached bidentate According to phosphite, no report in which the structure is precisely defined. In "Organometallics" (1995), pp. 3832-3838, and in "Inorganica Chimica Acta" (1996), pp. 125-136, is described by W.L. Gladfelter et al. a binuclear rhodium Complex described with bidentate phosphite. The structure of the complex is not exactly defined, however, and it is stated that the bidentate Phosphite is coordinated so that it crosslinks two rhodium atoms.

On the other hand, in a method in which a rhodium compound is used Carrying out the catalytic reaction and synthesizing a desired one Reaction product is used to separate the reaction product and the like. Pre-treatment of the catalyst liquid  for example, a distillation applied to the catalyst system. It is already known that such heat pretreatment leads to decomposition of the ligand can cause, which affects the catalyst system can be done. Therefore, methods for overcoming the above have been mentioned th problem proposed, for example the addition of an additive or an improvement in the structure of the ligand.

An object of the present invention is to develop a new rhodium complex To provide the appropriate to be used for a reaction in which a rhodium complex is used, for example a hydro formylation reaction (oxosynthesis reaction), and to suppress the Degradation of the ligand can contribute.

The inventors of the present invention have conducted intensive studies to achieve the above goal and they found that Zer setting of the ligand can be suppressed by changing the mode of the complex and the present invention is based thereon.

According to a first aspect, the present invention relates to a binuclear rhodium complex with a bidentate chelate ligandea of the following formula (1):

in which mean:
Q∩Q 'is a bidentate chelate ligand with the following formula (2):

in which Q ¹ and Q ² , which are independent of one another, each represent an element selected from the group consisting of phosphorus, arsenic and antimony, R ⁰ represents a bivalent organic group, Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, in each case represent a monovalent organic group or Z ¹ and Z ² and / or Z ³ and Z ⁴ are bonded to one another to form a divalent organic group,
x and z, which are independent of one another, each have a number from 0 to 2, and
y is a number from 0 to 4.

In addition, in a second aspect, the present invention relates to a process for producing an aldehyde which comprises
a reaction stage in which an olefinic compound is reacted with hydrogen and carbon monoxide in the presence of a rhodium complex catalyst comprising at least rhodium and an organic phosphite in a reaction zone to form an aldehyde,
a separation step in which the aldehyde is separated from the reaction product liquid taken out of the reaction zone to obtain a catalyst liquid containing the rhodium complex catalyst, and
a recycling stage in which the catalyst liquid is recycled into the reaction zone,
wherein at least one of the reaction, separation and recycling steps is carried out in the presence of the binuclear rhodium complex with bidentate chelate ligands defined in the first aspect of the invention above.

The invention is described below with reference to preferred embodiments tion forms described in more detail.

The binuclear rhodium complex with bidentate Che lat ligand is characterized by a structure in which a bidentate Chelate ligand coordinated to each rhodium atom in the binuclear complex is attached, which has a rhodium-rhodium bond, as in the above Formula (1) indicated, and it is clear that the structure is clearly different is of the binuclear rhodium complex, in which bidentate phosphite is coordinated with the networking of two rhodium atoms, such as from W.L. Gladfelter et al. described in the above reference. Moreover the remaining positions to be coordinated on rhodium are occupied by carbon monoxide, the formal oxidation number of which is 0-valent and x and z, each indicating the number of carbon monoxide molecules that are attached to coordinated at the end of each rhodium atom stand for one Number from 0 to 2 and y is the number of carbon monoxide molecules which is coordinated to link the rhodium atoms, stands for a number from 0 to 4, preferably from 0 to 2.

In addition, in the bidentate chelate ligand of formula (2), each of Q ¹ and Q ² , which are the same or different, represents an element selected from the group consisting of phosphorus, arsenic and antimony, preferably Q ¹ and Q ^{2 are the} same and especially before given both radicals Q ¹ and Q ^{2 are} phosphorus.

The crosslinking organic group represented by R ⁰ preferably represents a divalent organic group selected from the group consisting of an alkylene group, an alkylene oxyalkylene group, an arylene group and an arylene arylene group. In this case, each of the alkylene groups, which are the same or different, contains 2 to 18 carbon atoms and each of the arylene groups, which are the same or different, contains 6 to 24 carbon atoms.

Preferred crosslinking bivalent organic groups for R ⁰ are, for example, a 1,2-ethylene group, a 1,3-propylene group, a 1,4-butylene group, a 1,5-pentylene group, a 1,6-hexylene group, a 1 , 8-octylene group, a 1,2-phenylene group, a 1,3-phenylene group, a 2,3-naphthylene group, a 1,8-naphthylene group, a 1,1'-biphenyl-2,2'-diyl group, a 1,1'-binaphthyl-7,7'-diyl group, a 1,1'-binaphthyl-2,2'-diyl group, a 2,2'-binaphthyl-1,1'-diyl group or a 2,2 ' -Binaphthyl-3,3-diyl group. R ⁰ is particularly preferably a bivalent organic group which is a substituted or unsubstituted arylene-arylene group, very particularly preferred is a substituted arylene-arylene group of the following formula (3):

in which mean:
R ¹ and R ⁴ , which are independent of one another, each represent an alkyl group, a cycloalkyl group, an alkoxy group, a silyl group or a siloxy group which has at most 12 carbon atoms, a halogen atom or a hydrogen atom
R ² , R ³ , R ⁵ and R ⁶ which are independent of one another, an alkyl group, a cycloalkyl group, an alkoxy group, a silyl group or a siloxy group which has at most 20 carbon atoms, a halogen atom or a hydrogen atom, or
R ¹ and R ² and R ⁴ and R ⁵ , each of which is independent of the other, are linked together to form part of a saturated or unsaturated ring.

Each of the radicals R ¹ and R ⁴ can be, for example, a hydrogen atom, a linear or branched C 2 -alkyl group, z. B. a methyl group, an ethyl group, an n-propyl group, an isopropyl group or an n-butyl group; an alkoxy group corresponding to the alkyl group; a C _3-12 cycloalkyl group, for example a cyclopropyl group, a cyclopentyl group, a cyclohexyl group or a cyclooctyl group; a C _1-12 silyl group, for example a methylsilyl group; a C _1-12 siloxy group, for example a trimethylsiloxy group; or a halogen atom, for example a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

Each of the radicals R ² , R ³ , R ⁵ and R ⁶ can be, for example, a hydrogen atom, a linear or branched C _1-20 alkyl group, for example a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n- Butyl group, a t-butyl group, a t-pentyl group, a neopentyl group, a t-hexyl group, a nonyl group, an n-dodecyl group or an octa decyl group; an alkoxy group corresponding to the alkyl group; a C _3-20 cycloalkyl group, for example a cyclopropyl group, a cyclohexyl group, a cyclooctyl group or an adamantyl group; a silyl group, a siloxy group or a halogen atom, for example a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

A specific example of the formula (3) wherein R ¹ and R ² and / or R ⁴ and R ⁵ are linked to form a ring may be, for example, a 1,1'-binaphthyl-2,2'-diyl group which may have a substituent.

The particularly preferred substituted arylene-arylene group of the formula (3) is a substituted arylene-arylene group with a 1,1'-biphenyl-2,2'-diyl backbone or a 1,1'-binaphthyl-2,2'-diyl - Basic structure in which each of the radicals R ³ and R ⁶ , which are independent of one another, represents a branched C _3-20 alkyl group and each of the radicals R ² and R ⁵ , which are independent of one another, represents a branched C _1-20 -, preferably C _3-20 alkyl or alkoxy group. The most preferred structure is one in which R ³ , R ⁶ , R ² and R ^{5 represent} the groups given above and each of R ¹ and R ⁴ , which are independent of each other, represents a hydrogen atom, a C _{1- 3} alkyl or alkoxy group or a halogen atom.

Preferred as a crosslinking bivalent organic group R ⁰ are, for example, a 3,3'-di-t-butyl-1,1'-binaphthyl-2,2'-diyl group, a 3,3 ', 6,6'-tetra -t-butyl-1,1'-binaphthyl-2,2'-diyl group, a 3,3'-di-t-butyl-6,6'-di-t-butoxy-1,1'-binaphthyl-2 , 2'-diyl group, a 3,3'-di-t-pentyl-1,1'-dinaphthyl-2,2'-diyl group, a 3,3,6,6'-tetra-tra-t-pentyl- 1,1'-binaphthyl-2,2'-diyl group, a 3,3'-di-t-butyl-5,5'-dimethyl-1,1'-biphenyl-2,2'-diyl group, a 3, 3 ', 5,5'-tetra-t-butyl-1,1'-biphenyl-2,2'-diyl group, a 3,3', 5,5'-tetra-t-pentyl-1,1'- biphenyl-2,2'-diyl group, a 3,3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2-diyl group, a 3,3'-di-t -butyl-5,5 ', 6,6'-tetramethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3', 5,5'-tetra-t-butyl-6,6 -dimethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5'-tetra-t-pentyl-6,6'-dimethyl-1,1'-biphenyl-2, 2'-diyl group, a 3,3'-di-t-butyl-5,5'-dimethoxy-6,6'-dimethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3 ' , 5,5'-tetra-t-butyl-6,6'-dichloro-1, 1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5'-tetra-t-butyl-6,6'-diethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3,5,5'-tetra-t-butyl-6,6'-dimethoxy-1,1'-biphenyl-2,2'-diyl group, a 3,3'-di-t-butyl-5 , 5'-di methoxy-6,6'-dichloro-1,1'-biphenyl-2,2'-diyl group or a 3,3 ', 5,5'-tetra-t-butyl-6,6'- difluoro-1,1'-biphenyl-2,2'-diyl group.

In the formula (2), each of the terminal organic groups represented by Z ¹ , Z ² , Z ³ and Z ⁴ which are independent of each other is preferably a monovalent organic group selected from the group consisting of a substituted or unsubstituted one The alkyl group, cycloalkyl group, aryl group and heteroaryl group having at most 20 carbon atoms or the organic group can be a bivalent organic group in which Z ¹ and Z ² and Z ³ and Z ⁴ are connected to one another. The substituent is at least one monovalent substituent selected from the group consisting of an alkyl group, a haloalkyl group, a cycloalkyl group, an aryl group, a cyano group, a nitro group, a halogen atom, an alkoxy group, a carboalkoxy group, a silyl group and a siloxy group.

The monovalent organic group in which Z ¹ , Z ² , Z ³ and Z ^{4 are} not connected to one another can be, for example, a linear or branched C _1-20 alkyl group or substituted alkyl group, e.g. B. a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neo-pentyl group, a t-pentyl group, a t -Hexyl group or an aralkyl group; a C _3-20 cycloalkyl group, for example a cyclopropyl group, a cyclohexyl group, a cyclooctyl group or an adamantyl group; an aryl group which may have a substituent, for example a phenyl group, an α-naphthyl group, a β-naphthyl group, a methoxyphenyl group, a dimethoxyphenyl group, a carbomethoxyphenyl group, a cyanophenyl group, a nitrophenyl group, a chlorophenyl group, a dichlorophenyl group, a pentafluorophenyl group, a pentafluorophenyl group, a pentafluorophenyl group, a methylphenyl group, an ethylphenyl group, a dimethylphenyl group, a trifluoromethylphenyl group, a methylnaphthyl group, a methoxynaphthyl group, a chloronaphthyl group, a nitronaphthyl group or a tetrahydronaphthyl group; or a heteroaryl group, for example a pyridyl group, a methylpyridyl group, a nitropyridyl group, a pyridyl group, a pyrimidyl group, a benzofuryl group, a quinolyl group, an isoquinolyl group, a benzimidazolyl group or an indolyl group.

The divalent organic group in which Z ¹ and Z ² or Z ³ and Z ⁴ are connected to one another can be, for example, a C _2-40 alkylene group, for example a 1,2-ethylene group, a 1,3-propylene group, a 1,4-butylene group, a 1,1,2,2-tetramethyl-1,2-ethylene group or a 2,4-pentylene group; an arylene group, for example a 1,2-phenylene group, a 2,3-naphthylene group or a 1,8-naphthylene group; or an arylene-arylene group, for example a 1,1'-biphenyl-2,2'-diyl group, a 3,3'-dimethyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'- diyl group, a 3,3 ', 5,5'-tetramethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3'-di-t-butyl-5,5'-dimethyl-1, 1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5'-tetra-t-butyl-1,1'-biphenyl-2,2'-diyl group, a 3,3', 5 , 5'-tetra-t-butyl-6,6'-dimethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5'-tetra-t-pentyl-1, 1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5'-tetra-t-hexyl-1, 1'-biphenyl-2,2'-diyl group, a 3,3'-di -t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl group, a 3,3 ', 5,5', 6,6'-hexamethyl-1,1'-biphenyl -2,2'-diyl group, a 3,3'-di-t-butyl-5,5 ', 6,6'-tetramethyl-1,1'-biphenyl-2,2'-diyl group, a 1,1 '-Bi naphthyl-2,2'-diyl group, a 2,2'-binaphthyl-1,1'-diyl group, a 2,2'-bnaphthyl-3,3'-diyl group, a 3,3', 6 , 6'-tetramethyl-1,1'-binaphthyl-2,2'-diyl group or a 3,3 ', 6,6'-tetra-t-butyl-1,1'-binaphthyl-2,2-diyl group .

Preferred as Z ¹ , Z ² , Z ³ and Z ⁴ are a substituted or unsubstituted aryl group or heteroaryl group or an arylene-arylene group which may contain a hetero atom, and most preferred may be, for example, a monovalent group, for example a phenyl group 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2,4-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,6-dimethylphenyl group, a 2-methoxyphenyl group, a 3-methoxyphenyl group, a 4-methoxyphenyl group , a 2,4-dimethoxyphenyl group, a 2,5-dimethoxyphenyl group, a 2,6-dimethoxyphenyl group, an α-naphthyl group, a 3-methyl-α-naphthyl group, a 3,6-dimethyl-α-naphthyl group, a β-naphthyl group, a 1-methyl-β-naphthyl group, a 3-methyl-β-naphthyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 6-quinolyl group, an 8-quinolyl group or a 4th - Methyl-2-quinolyl group or a bi valent group, for example a 1,1'-biphenyl-2,2'-diyl group, a 3,3'-dimethyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl group, a 3rd , 3 ', 5,5'-tetramethyl-1,1'-biphenyl-2,2'-diyl group, a 3,3', 5,5 ', 6,6'-hexamethyl-1,1'-biphenyl- 2,2'-diyl group, a 1,1'-binaphthyl-2,2'-diyl group or a 2,2'-binaphthyl-3,3'-diyl group.

Examples of the preferred bidentate phosphite ligand comprising phosphorus preferred as Q ¹ and Q ² and a suitable combination of R ⁰ as the cross-linking group and Z ¹ , Z ² , Z ³ and Z ⁴ as the terminal group are shown in given in Table 1. However, the present invention is in no way limited to the ligands shown in Table 1.

Table 1

Table 1 (continued)

Table 1 (continued)

In Table 1, MeO stands for a methoxy group, ⁱ Pr stands for an i-propyl group and ^t Bu stands for a t-butyl group.

In the binuclear complex according to the invention, Q ¹ and Q ^{2 can be} arsenic or antimony. Such a binuclear complex can be, for example, its bidentate arsenide, where R ⁰ is a 3,3 ', 5,5'-tetra-t-butyl-6,6'-dimethyl-1,1'-biphenyl-2,2' -diyl group and Z ¹ to Z ⁴ stand for α-naphthyl groups, or a bidentate antimonide, where R ⁰ stands for 3,3 ', 6,6'-tetra-t-butyl-1,1'-binaphthyl-2, 2'-diyl group and Z ¹ to Z ⁴ represent 2-methylphenyl groups.

As indicated in formula (1) above, the structure of the binuclear rhodium complex with bidentate chelate ligand according to the invention is such that a bidentate chelate ligand in the binuclear complex which has a rhodium-rhodium bond is attached to each Rhodium atom is coordinatively attached. The most preferred combination of x, y, and z, which indicate the number of carbon monoxide molecules that occupy the remaining coordination positions, are the following four combinations:

• a) a binuclear rhodium complex with bidentate phosphite ligands, where x = 2, y = 0 and z = 2;
• b) a binuclear rhodium complex with bidentate phosphite ligands, where x = 1, y = 0 and z = 1;
• c) a binuclear rhodium complex with bidentate phosphite ligands, where x = 1, y = 2 and z = 1; and
• d) a binuclear rhodium complex with bidentate phosphite ligands, where x = 0, y = 2 and z = 0.

Specific examples of the preferred binuclear rhodium complex with bidentate chelate ligands according to the present invention include the preferred bidentate chelate ligands, the preferred combination of x, y and z being represented by the following formulas (4) to (11) :
Formula (4): (L1) (CO) ₂ Rh-Rh (CO) ₂ (L1)
Formula (5): (L1) (CO) ₁ Rh-Rh (CO) ₁ (L1)
Formula (6): (L2) (CO) ₂ Rh-Rh (CO) ₂ (L2)
Formula (7): (L2) (CO) ₁ Rh-Rh (CO) ₁ (L2)
Formula (8): (L3) (CO) ₂ Rh-Rh (CO) ₂ (L3)
Formula (9): (L3) (CO) ₁ Rh-Rh (CO) ₁ (L3)
Formula (10): (L4) (CO) ₁ Rh (µ-CO) ₂ Rh (CO) ₁ (L4)
Formula (11): (L4) Rh (µ-CO) ₂ Rh (L4)

In the formulas, the bidentate chelate ligands represented by L1, L2, L3 and L4 are bidentate phosphite ligands with the following structures:

As a common method for the synthesis of the binuclear rhodium complex with bidentate chelate ligand according to the invention, it is preferred to carry out the synthesis from a corresponding mono-nuclear rhodium hydride dicarbonyl complex with bidentate chelate ligand, for example one of the following formula (12):

RhH (CO) ₂ (Q∩Q ') (12)

wherein Q∩Q 'is as defined for formula (1). The synthesis of (L1) (CO) ₁ Rh-Rh (CO) ₁ (L1) of the formula (5) is exemplified below.

A corresponding mononuclear rhodium hydride dicarbonyl complex RhH (CO) ₂ (L1) is dissolved in a solvent in an inert gas atmosphere, preferably in nitrogen or argon gas, then heated until the desired binuclear rhodium complex has completely formed . In addition, a binuclear complex with four carbon monoxides, such as (L1) (CO) ₂ RhRh (CO) ₂ (L1) of the formula (4), can be easily synthesized, for example by blowing carbon monoxide through a solution of a corresponding precursor complex, for example a binuclear complex with two carbon monoxides.

In addition, (L) (CO) ₂ Rh-Rh (CO) ₂ (L) can be easily synthesized by bubbling carbon monoxide through a solution containing a rhodium precursor complex such as a binuclear rhodium (1,5-cyclooctadiene ) (acetate) complex and a bidentate chelate ligand, e.g. B. L1, contains dissolved therein.

Other binuclear rhodium complexes with bidentate chelate ligands can be synthesized using a similar procedure. The completeness of the reaction can be easily determined by a conventional method, for example the ³¹ P-NMR spectrum in the case where the bidentate chelate ligand is a phosphorus-type ligand, or generally by an infrared spectrum. The above synthesis of the complex can be carried out at a suitable temperature. It is effective at a temperature within a range from about 20 to about 130 ° C, preferably from about 40 to about 120 ° C, and to carry out the synthesis within a relatively short time is a temperature within the range from about 60 to about 110 ° C useful. The synthesis can be carried out under increased pressure, under normal pressure or under reduced pressure, preferably under normal pressure or under reduced pressure. It is important to carry out the synthesis under a low hydrogen partial pressure or under the condition of a low hydrogen concentration dissolved in the solution. The suitable solvent which can be used can be, for example, an aromatic hydrocarbon such as benzene, toluene , Xylene or ethylbenzene, an aliphatic hydrocarbon such as pentane, hexane, heptane, octane, nonane, decane, petroleum ether, cyclohexane or methylcyclo hexane, an ether such as diethyl ether, di-n-butyl ether, tetrahydrofuran, dioxane or 1,2-dimethoxyethane , a ketone such as acetone, 2-butanone or cyclohexane, an aldehyde or a condensed product of an aldehyde such as propionaldehyde, n-butyraldehyde, isobutyraldehyde, cyclohexanal or 2-ethylhexene, an ester such as ethyl acetate, n-butyl acetate or Ethyl butyrate, an alcohol such as methanol, ethanol, n-propanol, isopropanol, n-butanol or isobutanol, a high boiling condensate, which is a by-product in hydroformylation gs reaction is formed, or an olefinically unsaturated compound as a starting material for the hydroformylation reaction. The most preferred solvents are benzene, toluene, xylene, hexane, heptane, cyclo hexane, tetrahydrofuran and the like.

In addition, according to a second aspect, the invention relates to a method for producing an aldehyde which comprises
a reaction stage in which an olefinic compound is reacted with hydrogen and carbon monoxide in the presence of a rhodium complex catalyst which comprises at least rhodium and an organic phosphite in a reaction zone to form an aldehyde,
a separation step in which the aldehyde is separated from the reaction product liquid withdrawn from the reaction zone to form a catalyst liquid containing the rhodium complex catalyst, and
a recycling stage in which the catalyst liquid is recycled into the reaction zone,
wherein at least one of the reaction, separation and recycling steps is carried out in the presence of the binuclear rhodium complex with bidentate chelate ligands defined according to the first aspect above. The presence of the binuclear complex can suppress the decomposition of the ligand at high temperature.

It is particularly preferred that the binuclear rhodium complex has two toothy chelate ligand in the separation step in an amount of 0.1 to 100 mol%, preferably from 0.5 to 99.5 mol%, particularly preferably from 1.0 to 99.0 mol%, based on the total amount of the rhodium complex, is present.  

The rhodium complex catalyst is preferably used in the reaction onszone withdrawn reaction product liquid first in the binuclea ren rhodium complex with bidentate chelate ligand and then the reaction product liquid is introduced into the separation stage. As such a stage of the previous conversion of the rhodium complex Catalyst in the reaction product liquid in the binuclear rhodium For example, complex with bidentate chelate ligands can be one step the degassing of a synthesis gas and / or the olefin compound mentioned become.

In addition, the binuclear rhodium complex with two toothy chelate ligand in the catalyst liquid. In one in such a case the amount of the binuclear rhodium complex is two dentate chelate ligand in the catalyst liquid typically 0.2 to 100 mol%, preferably 0.5 to 99.8 mol%, particularly preferably 1.0 to 99.5 mol%, very particularly preferably 2.0 to 99.0 mol%, based on the Total amount of the rhodium complex.

Preferably, the binuclear rhodium complex with bidentate Catalyst liquid containing chelate ligands into the reaction zone right cyclized, for example by introducing them directly into a reactor, and the binuclear rhodium complex with bidentate chelate ligand converted into the active rhodium complex catalyst in the reaction zone delt.

Before the catalyst liquid containing the binuclear complex enters the Reaction zone is recycled, a stage of conversion of the called th binuclear complex in an active rhodium complex catalyst be carried out using a procedure that involves a pre-car bonylation stage, or a process involving the previous contact with hydrogen or synthesis gas.  

According to the binuclear complex is provided according to a ver drive the fresh addition of the binuclear complex or after a ver drive, in which it is formed in the process, the reaction stage, the Separation stage and the recycling stage includes.

The hydroformylation reaction according to the method of the invention can be carried out using a conventional method, with the exception, however, that the binuclear rhodium complex with bidentate chelate ligands as described above is present simultaneously. The rhodium complex catalyst to be used for the reaction can be prepared by a known method for producing a rhodium-organic phosphite complex catalyst. The rhodium complex catalyst can be prepared for the reaction or it can be formed from the rhodium compound and the organic phosphite in the reaction system. The rhodium compound to be used for the preparation of the catalyst can be, for example, an inorganic or organic salt of rhodium, such as rhodium chloride, rhodium nitrate, rhodium acetate, rhodium formate, sodium hexachlororhodate, potassium hexachlororhodate, rhodium metal, which is supported on a support such as aluminum oxide, silicon dioxide or activated carbon, has been applied, a chelate compound of rhodium such as rhodium dicarbonyl acetylacetonate or rhodium (1,5-cyclooctadiene) acetylacetonate or a carbonyl complex compound of rhodium such as tetrarhodium dodecacar bonyl, hexarhodium hexadecacarbonyl, μ, μ′-dichlororhodium (tetracarbonyl, [ µ-OAc) (COD)] ₂ , in which COD stands for 1,5-cyclooctadiene and Ac stands for an acetyl group, or [Rh (µ-St-Bu) (CO) ₂ ] ₂ , in which t-Bu stands for a tert -Butyl group stands.

Any organic phosphite can be used as the organic phosphite ligand are used, for example a triaryl phosphite, a trialkyl phosphite or an alkylaryl phosphite. In addition, a polyphosphite with a variety  of these phosphite structures in its molecule, for example bisphosphite or Triphosphite.

A particularly preferred organic phosphite according to the invention is an organic bidentate phosphite compound of the following formula (2 '):

in which mean:
R ^{0 is} a divalent organic group and
Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, each have a monovalent organic group or Z ¹ and Z ² and / or Z ³ and Z ⁴ are connected to one another to form a divalent organic group.

With respect to R ⁰ and Z ¹ to Z ⁴ , reference is made to the preferred examples as defined for the formula (2).

According to the hydroformylation reaction using ei a conventional process in which a rhodium Complex catalyst with an organic phosphite used as a ligand with the exception that the binuclear rhodium complex with bidentate chelate ligand is present. The reaction can be carried out by anyone the using the olefinic used as the starting material Compound itself as the main solvent. However, it is usually before added to use a solvent inert to the reaction. The Solvent can be, for example, an aromatic hydrocarbon, such as toluene, xylene or dodecylbenzene, a ketone such as acetone, diethyl ketone or Methyl ethyl ketone, an ether such as tetrahydrofuran or dioxane, an ester such as Ethyl acetate or di-n-octyl phthalate, an aldehyde used in hydroformyly  tion reaction is formed, for. B. n-butyraldehyde, i-butyraldehyde or valeral dehyde, or a mixture of high-boiling components, which is a minor product in the hydroformylation reaction, e.g. B. an aldehyde condensate. An aromatic hydrocarbon such as toluene or is particularly preferred Xylene, an aldehyde such as n-butyraldehyde or i-butyraldehyde, or a Mi high-boiling components that are a by-product of Hy droformylation reaction, or they can be used together.

The concentration of the rhodium complex catalyst in the reaction zone is usually 0.05 to 5000 mg, calculated as rhodium metal, in 1 l of liquid phase. The amount is preferably 0.5 to 1000 mg / l, in particular preferably 10 to 500 mg / l. The organic phosphite is usually in an amount used that is 0.1 to 500 times the molar amount, based on rhodium. It is preferably 0.1 to 100 times Molar amount, particularly preferably in 1 to 30 times the molar amount, based on rhodium. The organic phosphite can be a mixture of be two or more of the same.

The olefinic compound used as the starting material can be any as long as it has at least one olefinic double bond in its molecule. The olefinic double bond can be arranged at the end or inside the molecule. The carbon chain that builds the molecule can be linear, branched, or cyclic. In addition, the molecule may contain a carbonyl group, a hydroxyl group, an alkoxy group, an alkoxycarbonyl group, an acyl group, an acyloxy group or a halogen atom which is essentially inert to the hydroformylation reaction. Representative examples of the unsaturated olefinic compound include an α-olefin, an inner olefin, an alkyl alkenoate, an alkenyl alkanoate, an alkenyl alkyl ether and an alkenol. The unsaturated olefinic compound can be, for example, ethylene, propylene, butene, butadiene, pentene, hexene, hexadiene, octene, octadiene, nonene, decene, hexadecene, octadecene, eicosen, docosen, styrene, α-methylstyrene, cyclohexene, a lower olefin mixture , for example a propylene / butene mixture, a 1-butene / 2-butene / isobutylene mixture or a 1-butene / 2-butene / isobutylene / butadiene mixture, an olefin, for example a mixture of olefin oligomer isomers, e.g. B. the dimer to tetramer of a lower olefin such as propylene, n-butene or isobutylene, an olefinic hydrocarbon such as 3-phenyl-1-propene, 1,4-hexadiene, 1,7-octadiene or 3-cyclohexyl-1- butene, or an olefin substituted by a polar group, such as acrylonitrile, allyl alcohol, 1-hydroxy-2,7-octadiene, 3-hydroxy-1,7-octadiene, oleyl alcohol, 1-methoxy-2,7-octadiene, methyl acrylate , Methyl methacrylate, methyl oleate, oct-1-en-4-ol, vinyl acetate, aryl acetate, 3-butenyl acetate, aryl propionate, vinyl ethyl ether, vinyl methyl ether, aryl ethyl ether, n-propyl 7-octenoate, 3-butenenitrile or 5-hexenediamide. An unsaturated compound of the monoolefinic type which contains only one olefinic double bond in its molecule is preferably used. A C _2-20 olefin is particularly preferred and in particular propylene or 1-butene, 2-butene, isobutene or a mixture thereof or 1-octene or a mixed octene is particularly preferred.

The reaction temperature of the hydroformylation reaction is generally 15 to 150 ° C, preferably 30 to 130 ° C, particularly preferably 50 to 110 ° C. The reaction pressure is generally in the range from normal pressure up to 200 kg / cm ² G, preferably from 1 to 100 kg / cm ² G, particularly preferably from 3 to 50 kg / cm ² G. The molar ratio of hydrogen to carbon monoxide (H ₂ / CO) in the synthesis gas which is fed to the reaction zone is generally 10/1 to 1/10, preferably 1/1 to 6/1.

The reaction can be carried out using a continuous system or egg nes discontinuous system (batch systems) and in it is usually carried out using the continuous system leads. A stripping method can be used as the reaction mode, in which the olefin compound starting material and the synthesis gas are continuous are gradually introduced into a reaction zone that has a liquid phase contains with the rhodium complex catalyst, and the aldehyde formed  the reaction zone together with unreacted synthesis gas gene, as is commonly used; or a liquid recycling sation process in which the reaction solution containing a catalyst solvent, the olefin starting compound and the synthesis gas continuously Lich introduced into the reaction zone, which ent the aldehyde formed holding reaction product liquid continuously from the reaction zone removed and after at least the aldehyde formed has been separated that is, the reaction solvent containing the remaining catalyst in the reaction zone is recycled. The separation of the aldehyde formed in the liquid recycling process can be carried out under Using any method, for example by distillation, Extraction, crystallization, absorption or adsorption, and usually will distillation applied. In the step of separating the aldehyde from The reaction product liquid are carbon monoxide or hydrogen should be coordinated to the rhodium, not in the system available. Therefore, the rhodium complex is usually in one with a ligan the unsaturated state and tends to decompose and as a result there is a risk that the rhodium complex catalyst deactivates becomes.

The rhodium complex catalyst according to the invention, the organic Phos phite has as ligand, in particular has a high activity and accordingly, the hydroformylation reaction in many cases is as above imagines performed at a relatively low temperature. For the The case that the separation step is carried out by distillation is Temperature of the distillation stage higher than that of the reaction stage. In one In such a case, it is assumed that the rhodium complex catalyst at all is actually deactivated in the distillation stage. According to the invention However, if a specific binuclear rhodium Complex with bidentate chelate ligands is present, the deactivation of the catalyst in the step of separating the product, especially in the distillation stage. The decomposition of the rhodium  However, complex catalyst can be inevitable at a high temperature his. Therefore, the distillation temperature is preferably at most 150 ° C, particularly preferably at most 130 ° C. It is most preferred carry out the distillation at a temperature of 50 to 120 ° C. Therefore if the boiling point of the aldehyde is high, it is preferred that Distillation under reduced pressure, usually within a range from 755 mmHg to 1 mmHg, preferably from 750 mmHg to 5 mmHg respectively.

According to the invention, the reaction can take place over a long period of time usually for at least 1 month, without the Catalyst changed. In terms of cost, it is preferred to use the Kataly sator for as long as possible. According to the catalyst continuously over a long period of at least 6 months can be used and, if desired, it can continue for at least 1 year can be used.

The binuclear rhodium complex with bidentate Che lat ligands of formula (1) above can be used as a precursor for the catalyst, which is the rhodium complex catalyst for the hydrofor represents mylation reaction.

The binuclear complex according to the invention has in particular the effect that To suppress decomposition of the ligands at a high temperature, such as this is shown in the following examples. Therefore, through the property unit of the binuclear complex according to the invention at the time of Carrying out the heat pretreatment with the hydroformylation reaction Liquid significantly suppresses ligand degradation, which is advantageous in terms of cost, and besides that adverse influences on the catalyst system that lead to the decomposition are to be traced, suppressed.  

The case where heat pretreatment on the hydroformylation reaction tion composition is used, for example, a case where some of the components of the hydroformylation reaction Composition thereof is separated, in particular by distillation or evaporation.

The aldehyde obtained in the process according to the invention can be used directly be subjected to a hydrogenation reaction or it can in some cases dimerized and then subjected to a hydrogenation reaction under An using a known method such as that described in U.S. Patent 5,550,302 or described in U.S. Patent 5,667,644 to Bil an alcohol that is suitable for use as a plasticizer. According to the invention, butyraldehyde is obtained in particular from propylene and the butyraldehyde is hydrogenated to form butanol or the butyraldehyde hyd is dimerized and then hydrogenated to form 2-ethylhexanol.

On the priority document of the present application, the Japanese Pa Tent Application No. 10-275165, filed on September 29, 1998, is filed here expressly referred.

Examples

The invention is described below with reference to examples and ver similar examples explained in more detail. However, it is clear that the present invention is by no means limited to these specific examples.

Reference Example 1 (Synthesis of Ligand L1)

A toluene solution (about 200 ml) of α-naphthol (9.18 g, 63.6 mmol) and pyridine (5.03 g, 63.6 mmol) became a toluene solution (about 400 ml) of phosphorus trichloride (4.37 g, 31.8 mmol) was added dropwise over a period of about 2.5 h with stirring in a nitrogen atmosphere at 0 ° C. Then, the solid pyridine hydrochloride formed as a by-product was filtered off, and the filtrate was concentrated to about 50 ml by distilling off the solvent to obtain a toluene solution containing (C ₁₀ H ₇ O) ₂ PCl.

On the other hand, n-butyllithium (18.8 ml, 31.8 mmol) dissolved in hexane was dissolved in a concentration of 1.69 mol / e to a tetrahydrofuran solution (approx. 50 ml) of 3,3 ', 5,5'-tetra-t-butyl-6,6'-dimethyl-2,2'-biphenyldiol (6.98 g, 15.9 mmol) added dropwise in a nitrogen atmosphere at 0 ° C, then was about 1 h heated under reflux for a tetrahydrofuran solution Dilithium salt of 3,3 ', 5,5'-tetra-t-butyl-6,6'-dimethyl-2,2'-biphenyldiol held.

Then the dilithium salt of 3,3 ', 5,5-tetra-t-butyl-6,6'-dimethyl-2,2'-biphenyldiol dissolved in tetrahydrofuran was added to the above toluene solution, the C ₁₀ H ₇ O) ₂ PCl contained, added dropwise over a period of about 30 min with stirring in a nitrogen atmosphere at -70 ° C. After the dropping, the reaction solution was brought back to 0 ° C. at a rate of temperature increase of about 1.2 ° C./min. Then, the solid LiCl formed as a by-product was filtered off, and the filtrate was subjected to vacuum distillation to obtain the remaining liquid. This liquid was subjected to silica gel column chromatography (developer: toluene / hexane = about 1/5) to obtain a solution containing only bisphosphite (L1) and the solvent was distilled off under vacuum to give 6.3 g (yield: 36.9%) of a solid white powder.

The analytical values of the compound were as follows:
Elemental analysis:
measured value: C 78.73%; H 6.74%; P 5.58% * calculated value: C 78.48%; H 6.77%; P 5.78%.
* XRF (fluorometric X-ray analysis measurement)
³¹ P NMR (121 MHz, CDCl ₃ , 23 ° C), δ 131.1
(chemical shift, based on triphenyl phosphate)
¹ H NMR (300 MHz, CDCl ₃ , 23 ° C); δ 1.17 (18 H, s, 1.20 (18 H, s), 2.23 (6 H, s), 6.87 ~ 7.26 (18 H, m), 7.43 ~ 7, 48 (4 H, m), 7.56 (2 H, d, J = 7.9 H ₂ ), 7.80 (2 H, s), 8.11 (2 H, d, J = 7.9 Hz), 8.21 ~ 8.25 (2H, m).

Reference Example 2 (Synthesis of RhH (CO) ₂ (L3))

All of the following operations regarding the rhodium complex have been described in performed in a dry nitrogen gas atmosphere, which is exposed to the air was strictly completed, and the solvent to be used was severely deoxidized and dehydrated.

Di-µ-acetate-bis (1,5-cyclooctadiene) dirhodium (I) ([Rh (C ₈ H ₁₂ ) (µ-CH ₃ CO ₂ )] ₂ ) (0.7586 g, 2.808 mmol) and bisphosphite ( L3) (2.9297 g, 2.808 mmol) were placed in a 200 ml glass container with a magnetic stirrer inside. The atmosphere in the container was replaced with nitrogen and 120 ml of tetrahydrofuran was added to dissolve it. Then, a synthesis gas (H ₂ : CO = 1: 1) was bubbled into the solution for 10 minutes with stirring at 2000 and a volatile material was distilled off under reduced pressure. The residue obtained was washed with 40 ml of hexane three times, then dried under reduced pressure to obtain RhH (CO) ₂ (L3) as a white powder.

The analytical values of the compound were as follows:
³¹ P NMR (162 MHz, CDCl ₃ , 23 ° C), δ 157.3 (d, J = 238.8 Hz)
(chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 11.24 (1 H, br) 0.98 (18 H, s), 1.65 (18 H, s), 7.06 ~ 7.12 (4 H, m), 7.22 (2 H , d, J = 2.4 Hz), 7.26 ~ 7.43 (10 H, m), 7.47 ~ 7.52 (4 H, m) 7.55 (2 H, d, J = 2 , 4 Hz), 7.61 (2 H, d, J = 8.8 Hz), 7.64 ~ 7.69 (6 H, m), 7.73 (2H, d, J = 8.0 Hz ).
IR (CDCl ₃ solution): ν _RhH = 1980 cm ^-1 (shoulder).
ν _CO = 2027 cm ^-1 , 2076 cm ^-1 .

Reference Example 3 (Synthesis of RhH (CO) ₂ (L4))

Di-µ-acetate-bis (1,5-cyclooctadiene) dirhodium (I) ([Rh (C ₈ H ₁₂ ) (µ-CH ₃ CO ₂ )] ₂ ) (0.5084 g, 0.934 mmol) and bisphosphite ( L4) (1.5678 g, 1.869 mmol) were introduced into a 200 ml glass container with a magnetic stirrer inside. The atmosphere in the container was replaced with nitrogen and 80 ml of tetrahydrofuran was added to dissolve it. Then a synthesis gas (H ₂ : CO = 1: 1) was bubbled into the solution for 10 min at 20 ° C with stirring and a volatile material was distilled off under reduced pressure. The residue obtained was washed with 40 ml of hexane three times, then dried under reduced pressure to obtain (RhH (CO) ₂ (L4) as a white powder.

The analytical values of the compound were as follows:
³¹ P-NMR (162 MHz, CDCl ₃ , 23 ° C), δ 170.9 (d, J = 234.3 Hz) (chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 10.90 (1 H, dt, J = 10; 0 Hz, J = 3.2 Hz), 1.07 (18 H, s), 1.73 (18 H, s), 6.27 (2nd H, m), 7.11 (2 H, d; J = 2.8 Hz), 7.22 ~ 7.27 (4 H, m), 7.29 (2 H, d, J = 7.2 Hz), 7.40 (2 H, t, J = 7.2 Hz), 7.44 ~ 7.50 (6 H, m), 7.53 (2 H, d, J = 2.4 Hz) .
IR (CDCl ₃ solution): ν _RhH = 1987 cm ^-1 ν _CO = 2020 cm ^-1 , 2078 cm ^-1 .

example 1

Di-µ-acetate-bis (1,5-cyclooctadiene) dirhodium (I) ([Rh (C ₈ H ₁₂ ) (µ-CH ₃ CO ₂ )] ₂ ) (0.9600 g, 3.558 mmol) and the bisphosphite (L1) (3.8070 g, 3.554 mmol) as obtained in Reference Example 1 was introduced into a 200 ml glass container with a magnetic stirrer therein. The atmosphere in the container was replaced with nitrogen and 150 ml of tetrahydrofuran was added to dissolve it. Then, a synthesis gas (H ₂ : CO = 1: 1) was introduced into the solution with stirring at 20 ° C. for 20 minutes, and a volatile material was completely distilled off under reduced pressure. Then the residue obtained was dissolved in 60 ml of hexane, then refluxed for 70 minutes, and the volatile material was distilled off under reduced pressure to give (L1) (CO) Rh-Rh (CO (L1) in the form of a yellow Received powder.

The analytical values of the compound were as follows:
³¹ P NMR (162 MHz, CDCl ₃ , 23 ° C), δ 147.8 (dd, J = 183.9 Hz, J = 60.2 Hz) 160.9 (dd, J = 260.0 Hz, J = 60.2 Hz)
(chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 0.64 (18 H, s), 0.73 (18 H, s), 1.54 (18 H, s), 1.81 (18 H, s), 1.86 (6 H, s) , 1.92 (6 H, s), 6.96 ~ 7.81 (58 H, m), 8.26 (2 H, d, J = 8.4 Hz).
IR (toluene solution): ν _CO = 2022 cm ^-1

Example 2

10 mg (L1) (CO) Rh-Rh (CO) (L1) as obtained in Example 1 was introduced into an NMR tube, and 0.6 ml of CDCl _{3 was} added to dissolve it. CO gas was bubbled into this solution at 20 ° C for 5 minutes. The color of the solution changed from yellow to pale yellow within a few seconds and the formation of (L1) (CO) ₂ Rh-Rh (CO) ₂ (L1) was confirmed by the spectral data.

The analytical values of the compound were as follows:
³¹ P NMR (162 MHz, CDCl ₃ , 23 ° C), δ 148.5 (dd, J = 145.1 Hz, J = 57.2 Hz) 169.0 (dd, J = 228.8 Hz, J = 57.2 Hz)
(chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 0.44 (18 H, s), 0.64 (18 H, s), 1.58 (18 H, s) 1.71 (6 H, s), 1.74 (6 H, s), 1.98 (18 H, s), 6.86 ~ 7.79 (58 H, m), 8.68 (2 H, d, J = 8.8 Hz).
IR (toluene solution: ν _CO = 2002 cm ^-1 , 2035 cm ^-1 .

Example 3

The atmosphere in a 50 ml Schlenk-type glass container containing a magnetic stirrer was replaced with nitrogen and RhH (CO) ₂ (L4) (0.1092 g, 0.109 mmol) was introduced in a nitrogen atmosphere. To dissolve, 7 ml of tetrahydrofuran was added, followed by refluxing for 3 hours. The reaction solution was left to stand at room temperature for 5 days, whereby crystallites precipitated. The solvent was separated, then dried to give (L4) Rh (µ-CO) ₂ Rh (L4) in the form of brown crystals.

The analytical values of the compound were as follows:
³¹ P-NMR (162 MHz, CDCl ₃ , 23 ° C), δ 162.8 (m: AA 'XX' X "X '''- pattern J = 315.9 Hz: main doublet)
(chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 0.76 (36 H, s), 1.63 (36 H, s), 5.71 (4 H, t, J = 7.2 Hz), 6.16 (4 H, d, J = 8 , 4 Hz), 6.59 (4 H, d, J = 7.6 Hz), 6.66 (4 H, t, J = 7.8 Hz), 6.82 (4 H, d, J = 2.8 H ₂ ), 7.17 ~ 7.24 (12 H, m), 7.27 (4 H, d, J = 8.8 Hz), 7.32 ~ 7.37 (4 H, m ).
IR (CDCl ₃ solution): ν _CO = 1829 cm ^-1 .

Example 4

10 mg (L4) Rh (µ-CO) ₂ Rh (L4) as obtained in Example 3 was introduced into an NMR tube, and 0.6 ml of CDCl _{3 was} added to dissolve it. CO gas was bubbled into this solution at 20 ° C for 5 minutes. The color of the solution changed from reddish brown to yellow within a few seconds and the formation of (L4) (CO) Rh (µ-CO) ₂ Rh (L4) was confirmed by the spectral data.

The analytical values of the compound were as follows:
³¹ P-NMR (162 MHz, CDCl ₃ , 23 ° C), δ 166.5 (m: AA 'XX' X "X '''pattern, J = 256.5 Hz: main doublet)
(chemical shift, based on triphenyl phosphate)
¹ H NMR (400 MHz, CDCl ₃ , 23 ° C); δ 0.95 (36 H, s), 1.34 (36 H, s), 6.10 (4 H, d, J = 7.6 Hz), 6.85 (4 H, d, J = 2 , 4 Hz), 6.87 (4 H, td, J = 7.6 Hz, J = 1.2 Hz), 7.02 (4 H, td, J = 7.2 Hz, J = 1, 2 Hz), 7.22 7.29 (16 H, m), 7.33 (4 H, td, J = 5.6 Hz, J = 1.6 Hz), 7.39 (4H, dd, J = 7.2 Hz, J = 1.6 Hz).
IR (CDCl ₃ solution: ν _CO = 1816 cm ^-1 , 1837 cm ^-1 , 1980 cm ^-1 , 2021 cm ^-1 , 2062 cm ^-1 , 2075 cm ^-1 .

Example 5

The atmosphere in a 200 ml glass container containing a magnetic stirrer was replaced by nitrogen. The (L1) (CO) Rh- obtained in Example 1 Rh (CO) (L1) (0.6006 g, 0.250 mmol) and L1 (1.6056 g, 1.499 mmol) were in was introduced into a nitrogen atmosphere and 82.3 ml of toluene were dissolved admitted.

40 ml of this solution was transferred to another glass container in which the atmosphere was replaced with nitrogen, and then it was turned into one Micro-autoclaves of 100 ml placed in a nitrogen atmosphere. The inside re of the glass container was rinsed with a further 10 ml of toluene and the Reini supply liquid was added to the microautoclave to prepare 50 ml of a toluene solution (500 mg Rh / l, P / Rh (molar ratio) = 8) of (L1) (CO) Rh-Rh (CO) (L1).

The microautoclave was heated to 130 ° C in a nitrogen atmosphere for 135 hours, and the ³¹ P-NMR spectrum was measured to calculate the total amount of decomposed L1 ligands that were present in the solution. Compared to that used with ( L1) (CO) Rh-Rh (CO) (L1) was heated, the amount of ligands decomposed was 12.2%.

Comparative Example 1

40 ml of a toluene solution containing (L1) (CO) Rh-Rh (CO) (L1) and L1, prepared by the same method as in Example 5, was placed in another glass container in which the atmosphere was replaced with nitrogen, then heated to 60 ° C and a synthesis gas (H ₂ : CO = 1: 1) was bubbled into the solution for 10 min with stirring with a magnetic stirrer to synthesize RhH (CO) ₂ (L1) . Although about 10% of the binuclear complex remained in solution, most of the binuclear complex changed to RhH (CO) ₂ (L1). Then the gas phase was replaced by nitrogen and the solution was introduced into a 100 ml microautoclave in a nitrogen atmosphere. In a corresponding manner, the inside of the glass container was rinsed with a further 10 ml of toluene and the cleaning liquid was introduced into the microautoclave to prepare 50 ml of a toluene solution (500 mgRh / l, P / Rh = 8) of RhH (CO ) ₂ (L1).

The microautoclave was heated to 130 ° C in a nitrogen atmosphere for 135 hours and the ³¹ P-NMR spectrum was measured to calculate the total amount of the decomposed L1 ligands that were present in the solution. The amount of the decomposed ligands was 25 , 7%.

Example 6

The atmosphere of a 100 ml glass container containing a magnetic stirrer was replaced with nitrogen, and RhH (CO) ₂ (L3) (0.2923 g, 0.243 mmol) as obtained in Reference Example 2 and L3 ( 0.7603 g, 0.729 mmol) was added in a nitrogen atmosphere. To dissolve, 30 ml of tetrahydrofuran was added, then refluxed for 6 hours to synthesize (L3) (CO) Rh-Rh (CO) (L3), and a volatile material was completely distilled off under reduced pressure.

The yellow powder obtained was dissolved in 50 ml of toluene and placed in a 200 ml Autoclaves introduced in a nitrogen atmosphere to produce 50 ml a toluene solution (500 mgRh / l, P / Rh (molar ratio) = 8) of (L3) (CO) Rh- Rh (CO) (L3).

The autoclave was heated to 110 ° C in a nitrogen atmosphere for 16 hours and the ³¹ P-NMR spectrum was measured to calculate the total amount of the decomposed L3 ligands that was present in the solution. Compared to one heated with (L3) (CO) Rh-Rh (CO) (L3), the amount of ligands decomposed was 4.5%.

Comparative Example 2

RhH (CO) ₂ (L3) (0.2923 g, 0.243 mmol) as obtained in Reference Example 2 and L3 (0.7603 g, 0.729 mmol) were dissolved in 50 ml of toluene in a nitrogen atmosphere and put on the introduced in a 200 autoclave in the same manner as in Example 6 to prepare 50 ml of a toluene solution (500 mgRh / l, P / Rh (molar ratio) = 8) of RhH (CO) ₂ (L3).

The autoclave was heated to 110 ° C in a nitrogen atmosphere for 16 hours and the ³¹ P-NMR spectrum was measured to calculate the total amount of the decomposed L3 ligands that were present in the solution. Compared to one heated with RhH (CO) ₂ (L3), the amount of ligands decomposed was 24.7%.

Effects according to the invention

The novel binuclear rhodium complex with bidentate Chelate ligands has the effect of breaking down the ligands at a ho suppress temperature and is useful in a process for Carrying out a hydroformylation reaction (oxosynthesis reaction), at which uses a rhodium complex catalyst.

Claims (15)

1. Binuclear rhodium complex with bidentate chelate ligands, characterized by the following formula (1)
in which mean:
Q∩Q 'is a bidentate chelate ligand of the following formula (2):
wherein each of the radicals Q ¹ and Q ² , which are independent of one another, represents an element selected from the group consisting of phosphorus, arsenic and antimony, R ^{0 represents} a bivalent organic group and each of the radicals Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, represent a monovalent organic group or Z ¹ and Z ² and / or Z ³ and Z ⁴ are linked to form a divalent organic group,
x and z, which are independent of one another, each have a number from 0 to 2, and
y is a number from 0 to 4. 2. binuclear rhodium complex with bidentate chelate ligand according to claim 1, characterized in that in formula (2) mean:
R ^{0 is} a divalent group selected from the group consisting of an alkylene group, an alkylene oxyalkylene group (wherein each of the alkylene groups, which are the same or different, has 2 to 18 carbon atoms and may have a substituent), an arylene group and an arylene-arylene group (wherein each of the arylene groups, which are the same or different, contains 6 to 24 carbon atoms and may have a substituent and may contain a hetero atom) and
Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, in each case a monovalent group selected from the group consisting of an alkyl group, an aryl group and a heteroaryl group which contains at most 20 carbon atoms and can have a substituent, or Z ¹ and Z ² and / or Z ³ and Z ⁴ are bonded together to form a bivalent group. 3. binuclear rhodium complex with bidentate chelate ligand according to claim 1 or 2, characterized in that in the formula (2) mean:
R ^{0 is} an arylene-arylene group (wherein each of the arylene groups, which are the same or different, contains 6 to 24 carbon atoms and may have a substituent) and
Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, each have a monovalent group selected from the group consisting of an aryl group and a heteroaryl group which contains at most 20 carbon atoms and which may have a substituent. 4. binuclear rhodium complex with bidentate chelate ligand according to claim 1 or 2, characterized in that in the formula (2) mean:
R ^{0 is} an arylene-arylene group (wherein each of the arylene groups, which are the same or different, contains 6 to 24 carbon atoms and may have a substituent) and
Z ¹ and Z ² and / or Z ³ and Z ⁴ are connected to one another and form an arylene-arylene group, which may contain a hetero atom. 5. Binuclear rhodium complex with bidentate chelate ligand after one of claims 1 to 4, characterized in that in the formula (1) x = 2, y = 0 and z = 2. 6. Binuclear rhodium complex with bidentate chelate ligand one of claims 1 to 4, characterized in that in the formula (1) x = 1, y = o and z = 1. 7. Binuclear rhodium complex with bidentate chelate ligand after one of claims 1 to 4, characterized in that in the formula (1) x = 1, y = 2 and z = 1. 8. Binuclear rhodium complex with bidentate chelate ligand after one of claims 1 to 4, characterized in that in the formula (1) x = 0, y = 2 and z = 0. 9. A process for the preparation of an aldehyde, characterized in that it comprises
a reaction stage in which an olefinic compound is reacted with hydrogen and carbon monoxide in the presence of a rhodium complex catalyst comprising at least rhodium and an organic phosphite in a reaction zone to form an aldehyde,
a separation step in which the aldehyde is separated from the reaction product liquid withdrawn from the reaction zone to form a catalyst liquid containing the rhodium complex catalyst, and
a recycling stage in which the catalyst liquid is recycled into the reaction zone,
wherein at least one of the reaction, separation and recycling steps is carried out in the presence of the binuclear rhodium complex with bidentate chelate ligands as defined in one of claims 1 to 8. 10. The method according to claim 9, characterized in that the separators level in the presence of the binuclear rhodium complex with bidentate according to the chelate ligand. 11. The method according to claim 9 or 10, characterized in that the organic phosphite is an organic bidentate phosphite compound of the following formula (2 '):
in which mean:
R ^{0 is} a divalent organic group and
Z ¹ , Z ² , Z ³ and Z ⁴ , which are independent of one another, each have a monovalent organic group or Z ¹ and Z ² and / or Z ³ and Z ⁴ are connected to one another to form a divalent organic group. 12. The method according to any one of claims 9 to 11, characterized in net that the reaction stage, the separation stage and the recycling stage  fe carried out using a continuous flow system become. 13. The method according to any one of claims 9 to 12, characterized in net that the catalyst ver for at least 6 months for recycling is applied. 14. The method according to any one of claims 9 to 13, characterized in net that the olefinic compound is propylene. 15. A process for the preparation of an alcohol, characterized in that it comprises:
the direct hydrogenation of the aldehyde obtained in the process according to any one of claims 9 to 14 or
dimerizing said aldehyde and then hydrogenating the dimerized aldehyde.