KR20170051867A - Zinc complex including n,n-bispyrazolyl based ligand, catalyst for polymerization of monomer having a ring-type ester group, and method of forming polymer using the catalyst - Google Patents

Abstract

The present invention relates to a zinc complex containing an N,N-bispyrazolyl based ligand, a catalyst for polymerizing a monomer having a cyclic ester group, and a method of forming a polymer by using the same, wherein the zinc complex is represented by chemical formula 1, and in the chemical formula 1, Ar represents a cycloalkyl group, an alkoxy group, or a halogen group; L represents -(CH_2)_y- (while y is an integer of 1 to 5) or an arylene group; R_1 to R_4 represent independently hydrogen or an alkyl group; and X represents a halogen group.

Description

FIELD OF THE INVENTION The present invention relates to a catalyst for the polymerization of monomers having a cyclic ester group and a zinc complex containing an N, N-bis-pyrazolyl ligand, and a process for producing a polymer using the same. BACKGROUND ART A RING-TYPE ESTER GROUP, AND METHOD OF FORMING POLYMER USING THE CATALYST}

The present invention relates to a zinc complex containing an N, N-bis-pyrazolyl ligand, a catalyst for polymerizing a monomer having a cyclic ester group, and a process for producing a polymer using the same. More specifically, The present invention relates to a catalyst for polymerizing a monomer having a cyclic ester group capable of maximizing the conversion rate in the course of preparing a polymer exhibiting improved physical properties and a process for producing the polymer using the same.

Polylactide is excellent in impact resistance, flexibility and durability, and has excellent properties such as tensile strength, mechanical strength such as elastic modulus, surface gloss, chemical resistance, and the like, Is a widely used polymer. In particular, polylactide is a biodegradable polymer widely used for the packaging of food products, cosmetics containers, kitchen utensils, toys, and displays.

As a method for producing polylactide, there is known a method in which lactic acid is subjected to direct condensation polymerization or a ring-opening polymerization in which lactide monomer is ring-opened under an organometallic catalyst. Among them, the direct polycondensation method can produce a low-cost polymer, but it is difficult to secure sufficient physical and mechanical properties of the polylactide because it is difficult to obtain a polymer having a high molecular weight of 100,000 or more with an average molecular weight of 100,000 or more. The ring-opening polymerization method of lactide monomers requires lactide monomers to be prepared from lactic acid, so it requires a higher unit cost than the condensation polymerization, but it has a relatively high molecular weight and is used commercially because of its advantage in controlling the polymerization.

As a prior art document related to polylactide, Korean Patent Laid-Open Publication No. 2001-0135889 discloses a polylactide having a structure in which a hard segment of a polylactide repeating unit is bonded to both ends of a soft segment of a polyether polyol repeating unit, And a lactide copolymer that is linked to each other via a urethane linkage derived from the urethane linkage.

Korean Patent Laid-Open Publication No. 2010-0091092 also discloses an organometallic complex, a catalyst composition, and a process for producing a polylactide resin using the same, wherein the polylactide resin can be produced with a high conversion ratio. Is carried out in the presence of an initiator comprising a hydroxy group-containing compound. Here, when the polylactide resin is produced using the organometallic complex, the conversion rate can be attained up to 60% or more and 90% or less. In the case of the initiator, the addition amount of the initiator increases, or the initiator has a long chain as the hydroxyl group- It is disclosed that the molecular weight of the polylactide resin can be reduced to function as a molecular weight control agent.

Korean Patent Laid-Open Publication No. 2010-0072933 relates to a process for producing polylactide particles directly by charging a mixture of polylactide and lactide monomer into a reactor, followed by stirring, liquefaction and cooling. By this method, only the polylactide in crystallized and granulated form can be obtained.

Korean Patent Laid-Open Publication No. 2011-0024610 discloses an organometallic catalyst for producing polylactide resin, a method for producing a polylactide resin using the organometallic catalyst, and a polylactide resin produced by the method. The polylactide resin The organometallic catalyst for preparation has a structure containing tin and an alkoxy group, and the conversion rate of the polylactide resin can be attained up to 90%, and the polylactide resin can be produced by the activity of the catalyst itself without a separate initiator have.

Korean Patent Laid-Open Publication No. 2009-0059880 also relates to a method for producing a block copolymer by ring-opening polymerization of a cyclic ester monomer, and more particularly, to a method for producing a block copolymer by ring opening polymerization of a cyclic ester monomer by using a polyalkylene glycol containing a hydroxy group at the chain terminal, And using a strong acid catalyst having a pKa of less than 1 as a polymerization catalyst, one or more cyclic monomers selected from lactide (LA) segments, caprolactone (CL) segments and glycolide (GA) The present invention relates to a process for producing a polyester block copolymer which solves the problems of toxicity persistence of an organometallic catalyst and the impossibility of ring-opening polymerization by a known acid catalyst.

And [ Michigan State UniVersity Research Team, J. Am. Chem. Soc. 2000, 122 , 1552-1553], a complex having four coordination numbers, which has an L-type lactide, a D-type lactide and a meso-lactide as a catalyst, with a complex in which N and O atoms are coordinated to the center of an Al metal (S) -1-Phenyl-N - [(S) -1- (2-methoxyphenol)] as a zinc metal complex catalyst in Kyungpook National University Research Team, Polyhedron, 2012 , 43 , 55-62 N atom is coordinated to the central metal using two ligands of (S) -1- (6-methylpyridin-2yl) -N - [(S) -1-phenylethyl] ethanamine , 3,6-Dimethyl-1,4-dioxane-2,5-dione (Monomer = Lactide).

As known from the above-mentioned patent documents and papers, only the initial conversion rate of 90% is achieved, and there is a limit to maximizing the conversion rate.

On the other hand, the heterotacticity when the asymmetric center of polylactide exists, the specific property of the polymer itself is influenced by the fact that a catalyst having an asymmetric center does not have the desired activity and heterotacticity, It is difficult to control the physical properties of the resin.

It is an object of the present invention to provide a zinc complex containing an N, N-bis-spiazolyl ligand as a compound having a novel structure.

Another object of the present invention is to provide a catalyst for polymerizing a monomer having a cyclic ester group capable of maximizing the conversion ratio of the polymer to nearly 100% and increasing the heterolepticity of the polymer without asymmetric center.

It is still another object of the present invention to provide a method for producing a polymer using the catalyst for polymerization.

A zinc complex containing an N, N-bis-spiazolyl ligand for one purpose of the present invention is represented by the following formula (1).

[Chemical Formula 1]

In the formula (1), Ar represents a cycloalkyl group, an alkoxy group or a halogen group, L represents - (CH ₂ ) _y - (wherein y is an integer of 1 to 5) or an arylene group, and R ₁ to R ₄ each independently Represents hydrogen or an alkyl group, and X represents a halogen group.

The catalyst for the polymerization of monomers having a cyclic ester group for another purpose of the present invention includes a zinc complex containing an N, N-bis-spiazolyl ligand represented by the general formula (1).

In one embodiment, the zinc complex may have catalytic activity by a methyllithium lithium bromide complex.

In one embodiment, the zinc complex is selected from the group consisting of glycolide (1,4-dioxane-2,5-dione), gamma-caprolactone

2-oxepanone, L-lactide, (3S) -cis-3,6-dimethyl-1,4-dioxane-2,5-dione and lactide -Dimethyl-1,4-dioxane-2,5-dione).

The method for producing a polymer according to another aspect of the present invention includes a step of mixing a zinc complex represented by the formula (1) with a monomer having a cyclic ester group to form a polymer.

In one embodiment, in the step of forming the polymer, the polymerization reaction may be carried out at a temperature of from -50 ° C to 25 ° C.

In one embodiment, in the step of forming the polymer, the conversion of monomer to polymer at -25 ° C to 25 ° C may be 100%.

In one embodiment, the polymer produced at -50 ° C to -25 ° C in the step of forming the polymer may have a heterotacticity of 0.7 to 0.95.

In one embodiment, the monomer is selected from the group consisting of glycolide (1,4-dioxane-2,5-dione), gamma-caprolactone

2-oxepanone, L-lactide, (3S) -cis-3,6-dimethyl-1,4-dioxane-2,5-dione and lactide -Dimethyl-1,4-dioxane-2,5-dione).

In one embodiment, the method of manufacturing the polymer further comprises activating the zinc complex by mixing the zinc complex with the co-catalyst prior to mixing the zinc complex with the monomer, wherein the activated zinc complex Can be used as a catalyst for the polymerization of the monomer.

In one embodiment, the cocatalyst may comprise a methyllithium lithium bromide complex.

According to the catalyst for polymerization of a monomer having a cyclic ester group and a method for producing a polymer using the same, the zinc complex containing the N, N-bis-pyrazolyl ligand of the present invention as described above, the zinc complex is a compound chemically stable in air And does not include an asymmetric center.

Thus, the zinc complex can be used chemically stably as a catalyst for the preparation of polymers, in particular as a catalyst for the polymerization of polylactides, and the heterotacticity of the polymers produced is at or below < RTI ID = 0.0 > ≪ / RTI > and exhibits properties that are different from conventionally known polylactides.

In addition, when the polymer is prepared from the catalyst containing the zinc complex, the conversion of the monomer used can reach up to substantially 100%. That is, since there are few monomers remaining in the produced polymer, the toxicity due to the residual monomer can be fundamentally removed and no additional cost is required to remove metal residues.

1 is a view showing a structure of a zinc complex sample 2 of the present invention.
2 is a view showing a homonuclear decoupled ¹ H-NMR spectrum according to the reaction temperature when the polylactide is produced using the zinc complex sample 4 of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term "comprises" or "having ", etc. is intended to specify that there is a feature, step, operation, element, part or combination thereof described in the specification, , &Quot; an ", " an ", " an "

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

As a result of intensive investigation and study of the above-mentioned prior arts, applicants have designed a zinc complex containing a ligand that contains N atoms but does not become asymmetric center, and does not use an acid catalyst And can be used as a catalyst for polymerization of activated lactide by using methyl lithium as a cocatalyst. The present invention has been completed based on this finding. The lactic acid conversion rate of the polylactide produced by the zinc complex is substantially 100%, which will be described in detail below.

The zinc complex according to the present invention is an organic-metal compound containing zinc (Zinc, Zn) as a metal and a non-spirazolyl ligand as an organic substance and is represented by the following formula (1).

[Chemical Formula 1]

In formula (1)

Ar represents a cycloalkyl group, an alkoxy group or a halogen group, L represents - (CH ₂ ) _y - (wherein y is an integer of 1 to 5) or an arylene group, R ₁ to R ₄ each independently represent hydrogen or an alkyl group And X represents a halogen group.

The "cycloalkyl group" is a functional group including a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and the like, and may have 5 or more carbon atoms. Preferably, the cycloalkyl group may have from 5 to 7 carbon atoms.

The "alkoxy group" is represented by "-OR ", wherein R is a functional group representing an alkyl group and may have 1 or more carbon atoms. Preferably, the alkoxy group may have 1 to 3 carbon atoms.

"Halogen group" represents chlorine, bromine or iodine.

The term "arylene group" means a divalent substituent derived from an aromatic hydrocarbon, such as a phenylene group, a naphthalene group, and the like, and may have 6 or more carbon atoms. For example, the arylene group may have from 6 to 20 carbon atoms and preferably from 6 to 10 carbon atoms.

The "alkyl group" represents a methyl group, an ethyl group, etc., and includes at least 1 carbon atom. The alkyl group may have 1 to 10 carbon atoms.

As specific examples, Ar represents a cyclohexyl group, a methoxy group or a halogen group, L represents - (CH ₂ ) _y - (wherein y is an integer of 1 to 3) or a phenylene group, and R ₁ To R < ₄ > each independently represent hydrogen or a methyl group, and X may represent chlorine.

More specifically, the zinc complex represented by the above formula (1) can be represented by the following formula (1a), (1b), (1c), (1d) or (1e).

[Formula 1a]

 [Chemical Formula 1b]

[Chemical Formula 1c]

≪ RTI ID = 0.0 &

[Formula 1e]

The zinc complex represented by the above-described formula (1) can be prepared by reacting an N, N-pyrazolyl aniline derivative ligand based on aniline and non-spirazole with zinc chloride. The zinc complex represented by the formula (1) has high stability in air and can be produced at a low cost and a high yield. The N, N-pyrazolyl aniline derivative ligand may be represented by the following formula (2).

(2)

In the general formula (2), Ar, L and R ₁ to R ₄ are substantially the same as Ar, L and R ₁ to R ₄ described in the general formula (1), and overlapping descriptions will be omitted.

Specifically, the compound represented by the formula (2) may be a compound represented by the following formula (2a), (2b), (2c), (2d) or (2e).

(2a) (2b)

[Chemical Formula 2c] (2d)

[Formula 2e]

The zinc complex represented by the above-described formula (1) is used as a catalyst in the polymerization reaction of monomers having a cyclic ester group. The zinc complex acts as a catalyst to open a ring of monomers to produce a polymer having an ester group in the ring-loosened form.

Examples of monomers having a cyclic ester group include glycolide (1,4-dioxane-2,5-dione), gamma-caprolactone (2-oxepanone), L- (3S) -cis-3,6-dimethyl-1,4-dioxane-2,5-dione, lactide (3,6-Dimethyl-1,4-dioxane-2,5- . In the present invention, the zinc complex represented by the formula (1) acts as a catalyst for polymerization, and is suitable for the production of a polymer showing a heterotaxy sheet. There are two chiral centers and a monomer having an ester group in the ring- .

In one embodiment, in the polymerization of the lactide having an alkyl group and a hexagonal cyclic ester group, a zinc complex represented by the above formula (1) is used as a catalyst, and a separate promoter may be used. The cocatalyst activates the zinc complex to form a substantially catalytically active species, and at the same time becomes an initiator of the ring-opening polymerization reaction. That is, the activity of the catalyst of the zinc complex can be increased by the co-catalyst, and the increase of the activity of the catalyst can further improve the conversion ratio of the monomer to the polymer. On the other hand, the cocatalyst is involved in some depolymerization or decomposition of the molecules to control the molecular weight of the polymer.

The cocatalyst of the present invention may be a methyl lithium based complex. For example, methyllithium lithium bromide complex (CAS No. 332360-06-2, CH ₃ BrLi ₂ ) may be used as the methyllithium complex. The methyllithium lithium bromide complex is a known compound widely used in a general synthetic technique for catalytically polymerizing an olefin or an olefin copolymer, and a compound commercially available from Tosoh Co. can be used.

A methyl lithium lithium bromide complex activates the zinc complex to open the monomer, and two asymmetric centers are created in the polymerized polymer due to the monomer. Although the zinc complex does not contain a chiral center, the polymer produced may have a heterotacticity of greater than 90%. Also, the conversion of the polymer in the monomer can be at least about 80%, and at most about 100%.

In the preparation of the polymer using the zinc complex and the cocatalyst, first, the zinc complex and the cocatalyst are mixed and stirred for a predetermined time to activate the zinc complex by co-catalyst, and then the activated zinc complex and the monomer are mixed Polymer can be prepared due to the ring-opening polymerization of the monomer. As the monomer, a lactide may be used, and finally, a polylactide may be prepared as a polymer.

The zinc complexing agent represented by the above-mentioned formula (1) is chemically stable in air and can be chemically stably used as a catalyst for the production of polymers, in particular for the polymerization of polylactide, and the zinc complexes are asymmetric The heterotacticity of the prepared polymer, which does not include the center, is at least 0.7 at -25 DEG C or less, indicating properties differentiating from the conventionally known polylactide. In addition, when the polymer is prepared from the catalyst containing the zinc complex, the conversion of the monomer used can reach up to substantially 100%. That is, since there are few monomers remaining in the produced polymer, the toxicity due to the residual monomer can be fundamentally removed and no additional cost is required to remove metal residues.

Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples.

Preparation of N, N-pyrazolyl aniline derivative ligands

A. Preparation of (1-H-Pyrazole-1-yl) methanol

After dissolving 20.4 g (0.300 mol) of pyrazole and 9.0 g (0.300 mol) of para-formaldehyde in 400 mL of methylene chloride, the reaction was carried out at 60 ° C. for 4 days using a reflux condenser . The reaction mixture was dried under reduced pressure, and the reaction mixture obtained after the removal was washed with 100 ml of hexane three times, followed by vacuum drying under reduced pressure. The yield of (1H-1-pyrazolyl-1-methanol) obtained was 34.8 g (96.6%).

B. Preparation of (3,5-dimethyl-1H-pyrazol-1-yl) methanol

The procedure described above was repeated using 28.8 g (0.300 mol) of 3,5-dimethyl pyrazole instead of pyrazole to give (3,5-dimethyl-1H-pyrazole -1-yl) methanol. The yield was 36.3 g (95.9%).

Preparation of ligand

[Ligand 1, L _One ], Ligand 1:

N, N-bis ((1H-pyrazol-1-yl) methyl) (cyclohexyl) methanamine (hereinafter referred to as ligand L ₁ ) was prepared by the following method with reference to Inorganic Chemistry Communications 44 (2014) 164-168.

First, cyclohexylmethanamine (2.26 g, 0.0200 mol) was dissolved in CH ₂ Cl ₂ (30.0 mL) and 1H-1-pyrazolyl-1-methanol (3.92 g, 0.0400 mol) was added to a CH ₂ Cl ₂ solvent And dissolved. Was 24 hours at room temperature and removed by the water in the reaction solution with MgSO _4, the solution was removed by pressure. After distillation under reduced pressure, a colorless oil was obtained. (5.28 g, 80.2%)

[Ligand 2, L ₂ ], Ligand 2:

(3,5-dimethyl-1H-pyrazol-1-yl) methylene methanamine (hereinafter referred to as ligand L ₂ ) The title compound was prepared in substantially the same manner as the preparation of ligand 1 except that methanol (5.04 g, 0.0400 mol) was used to obtain a white solid. (5.02 g, 72.0%)

[Ligand 3, L ₃ ], Ligand 3:

N, N-bis ((1H-pyrazol-1-yl) methyl) -3-methoxypropan-1-amine (hereinafter referred to as ligand L ₃ ) was synthesized according to Inorganic Chemistry Communications 44 (2014) ≪ / RTI >

First, a 3-methoxypropan-1-amine ( 2.04 mL, 0.0200 mol) with CH ₂ Cl ₂ solvent (30.0 mL) was dissolved, 1H-1-pyrazolyl-1 -methanol (3.92 g, 0.0400 mol) in CH ₂ Cl ₂ Dissolved in a solvent (20.0 mL). Was 24 hours at room temperature and removed by the water in the reaction solution with MgSO _4, the solution was removed by pressure. After distillation under reduced pressure, a colorless oil was obtained. (4.54 g, 91.1%).

[Ligand 4, L ₄ ], Ligand 4:

[3-methoxy-N, N -bis ((3,5-dimethyl-1H-pyrazol-1-yl) methyl) propan-1-amine] ( hereinafter, the ligand L ₄₎ a, (3,5-dimethyl- 1H-pyrazol-1-yl) methanol (5.04 g, 0.0400 mol) in the same manner as in the preparation of ligand 3, a colorless oil was obtained. (5.42 g, 88.8%).

Analysis calculated for C ₁₆ H ₂₇ N ₅ : C, 62.9%, H, 8.91%, N, 22.9%. Found: C, 60.9%, H, 8.92%, N, 21.5%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 5.79 (s, 2H, -N = C (CH 3) -CH = C (CH 3) -N-), 4.90 (s, 4H, -N-CH _{2 -N-), 3.21 (s,} 3H, CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 3.19 (d, 2H, J = 6.4 Hz, CH 3 -O-CH 2 -CH ₂ -CH ₂ -N-), 2.68 (t, 2H, J = 6.8 Hz, -CH ₃ -O-CH ₂ -CH ₂ -CH ₂ -N-), 2.19 CH ₃ ) -CH = C (CH ₃ ) -N-), 1.56 (m, 2H, -CH ₃ -O-CH ₂ -CH ₂ -CH ₂ -N-).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 147.78 (s, 2C, -N = C (CH 3) -CH = C (CH 3) -N-), 139.99 (s, 2C, -N = C _{(CH 3) -CH = C (} CH 3) -N-), 106.93 (d, 2C, J = 171 Hz, -N = C (CH 3) -CH = C (CH 3) -N-), 70.78 (t, 1C, J = 140 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 65.89 (t, 2C, J = 148 Hz, -N-CH 2 -N-), 59.52 (q, 1C, J = 140 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 46.26 (t, 1C, J = 133 Hz, -CH 3 -O-CH 2 - _{CH 2 -CH 2 -N-), 27.85} (t, 1C, J = 126 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 14.47 (q, 2C, J = 127 Hz _{, -N = C (CH 3)} -CH = C (CH 3) -N-), 11.87 (q, 2C, J = 127 Hz, -N = C (CH 3) -CH = C (CH 3) - N-).

IR (liquid neat; cm ^-1 ): 3132 (w), 2927 (m), 2869 (m), 1554 (m), 1454 (s), 1377 1112 (s), 1030 (m), 977 (m), 898 (w), 783 (s), 721 (m), 628 (w).

[Ligand 5, L ₅ ], Ligand 5:

First, 4-bromobenzenamine (3.44 g, 0.0200 mol) was dissolved in a CH ₂ Cl ₂ solvent (30.0 mL) for the preparation of N, N-bis ((1 H-pyrazol- 1-pyrazolyl-1-methanol (3.92 g, 0.0400 mol) was dissolved in a CH ₂ Cl ₂ solvent (20.0 mL) and added. Was 24 hours at room temperature and removed by the water in the reaction solution with MgSO _4, the solution was removed by pressure. After distillation under reduced pressure, a green solid was obtained. (5.89 g, 88.7%)

_{Analysis calculated for C 14 H 14 N} 5: C, 50.6%; H, 4.25%; N, 21.1%. Found: C, 50.7%; H, 4.23%; N, 21.9%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 7.58 (d, 2H, J = 1.6 Hz, -N = CH-CH = CH-N-), 7.44 (d, 2H, J = 2.4 Hz, -N = CH-CH = CH-N- ), 7.38 (d, 2H, J = 9.2 Hz, m -NC 6 H 4 Br-), 7.05 (d, 2H, J = 9.2 Hz, o -NC 6 H 4 Br -), 6.28 (dd, 2H , J = 1.6 Hz, J = 2.0 Hz, -N = CH-CH = CH-N-), 5.69 (s, 4H, -N-CH 2 -N-).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 144.84 (s, 1C, ipso -NC 6 H 4 Br-), 140.11 (d, 2C, J = 176 Hz, -N = CH-CH = CH-N -), 132.32 (d, 2C , J = 165 Hz, m -NC 6 H 4 Br-), 128.89 (d, 2C, J = 175 Hz, -N = CH-CH = CH-N-), 117.51 ( d, 2C, J = 164 Hz , o -NC 6 H 4 Br-), 113.64 (s, 1C, p -NC 6 H 4 Br-), 106.43 (d, 2C, J = 176 Hz, -N = CH -CH = CH-N-), 66.24 (t, 2 C, J = 151 Hz, -N-CH ₂ -N-).

IR (liquid neat; cm ^-1 ): 3108 (m), 1594 (m), 1496 (s), 1431 (m), 1416 (w), 1390 (s), 1296 1244 (m), 1188 (s), 1082 (s), 1044 (s), 987 (m), 971 (s), 881 (m), 822 (s), 632 (s), 589 (m).

Preparation of zinc complex samples

Zinc complex Sample 1: [L _One ZnCl ₂ ]

A solution of the ligand [L ₁ ] (0.273 g, 1.00 mmol) dissolved in 10 ml of ethanol and a solution of ZnCl ₂ (0.136 g, 1.00 mmol) in 10 ml of ethanol were mixed and reacted at 25 ° C for 24 hours. The reaction solvent was removed by vacuum decompression drying, and 30 ml of cold ethanol was washed three times, and then washed three times with 30 ml of hexane to obtain a white solid compound. The yield was 0.370 g (90.2%).

Analysis calculated for C ₁₅ H ₂₃ Cl ₂ N ₅ Zn: C, 43.9%, H, 5.66%, N, 17.0%. Found: C, 43.9%, H, 5.69%, N, 16.4%.

^{1 H-NMR (DMSO, 400} MHz): δ 7.79 (d, 2H, J = 2.4 Hz, -N = CH-CH = CH-N-), 7.50 (d, 2H, J = 1.6 Hz, -N = CH-CH = CH-N-) , 6.29 (t, 2H, J = 2.0 Hz, -N = CH-CH = CH-N-), 5.08 (s, 4H, -N-CH 2 -N-), 2.32 (d, 2H, J = 6.8 Hz, -C ₆ H ₁₁ -CH ₂ -N-), 1.73-1.40 (m, 6H, -C ₆ H ₁₁ -), 1.17-1.02 ₆ H ₁₁ -), 0.65-0.56 (m, 2H, -C ₆ H ₁₁ -).

_{^{13 C- NMR (CDCl 3, 100MHz}} ): δ 140.29 (d, 2C, J = 189 Hz, -N = CH-CH = CH-N-), 131.86 (d, 2C, J = 186 Hz, -N = CH-CH = CH-N-) , 106.65 (d, 2C, J = 175 Hz, -N = CH-CH = CH-N-), 69.00 (t, 2C, J = 149 Hz, -N-CH 2 -N-), 56.01 (t, 1C , J = 128 Hz, -C 6 H 11 -CH 2 -N-), 35.62 (d, 1C, J = 118 Hz, ipso -C 6 H 11 -), 30.82 (t, 2C, J = 122 Hz, o -C 6 H 11 -), 26.56 (t, 1C, J = 127 Hz, p -C 6 H 11 -), 25.74 (t, 2C, J = 126 Hz, m -C ₆ H ₁₁ -).

IR (solid neat; cm ^-1 ): 3745 (w), 2924 (w), 2849 (w), 1748 (w), 1692 (w), 1649 (M), 1318 (m), 1247 (m), 1165 (s), 1068 (s), 986 (m), 914 (w), 776 613 (m).

Zinc complex Sample 2: [L ₂ ZnCl ₂ ]

A solution of ligand [L ₂ ] (0.329 g, 1.00 mmol) dissolved in 10 ml of ethanol and a solution of ZnCl ₂ (0.136 g, 1.00 mmol) in 10 ml of ethanol were mixed and reacted at 25 ° C for 24 hours. The reaction solvent was removed by vacuum decompression drying, and 30 ml of cold ethanol was washed three times, and then washed three times with 30 ml of hexane to obtain a white solid compound. The yield was 0.430 g (91.5%).

The structure of the prepared zinc complex sample 2 is shown in Fig. 1, and the results of the analysis are shown in Table 1 and Table 2 below. The coupling lengths and coupling angles of Table 2 depend on the number of each element shown in FIG.

Analysis calculated for C ₁₉ H ₃₁ Cl ₂ N ₅ Zn: C, 48.9%, H, 6.71%, N, 15.0%. Found: C, 48.8%, H, 6.72%, N, 15.0%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 6.04 (s, 2H, -N = C (CH 3) -CH = C (CH 3) -N-), 4.93 (s, 4H, -N-CH _{2 -N-), 2.65 (s,} 6H, -N = C (CH 3) -CH = C (CH 3) -N-), 2.32 (s, 6H, -N = C (CH 3) -CH = _{C (CH 3) -N-),} 2.25 (d, 2H, J = 7.2 Hz, -C 6 H 11 -CH 2 -N-), 1.80-1.71 (m, 5H, -C 6 H 11 -), _{1.54-1.47 (m, 1H, -C 6} H 11 -), 1.29-1.15 (m, 3H, -C 6 H 11 -), 0.93-0.84 (m, 2H, -C 6 H 11 -).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 146.89 (s, 2C, -N = C (CH 3) -CH = C (CH 3) -N-), 140.33 (s, 2C, -N = C _{(CH 3) -CH = C (} CH 3) -N-), 106.89 (d, 2C, J = 173 Hz, -N = C (CH 3) -CH = C (CH 3) -N-), 65.13 (t, 2 C, J = 149 Hz, -N-CH ₂ -N-), 55.23 (t, 1C, J = 137 Hz, -C ₆ H ₁₁ -CH ₂ -N-), 35.69 _{J = 126 Hz, ipso -C 6} H 11 -), 31.02 (t, 2C, J = 124 Hz, o -C 6 H 11 -), 26.55 (t, 1C, J = 125 Hz, p -C 6 H _{11 -), 25.72 (t,} 2C, J = 121 Hz, m -C 6 H 11 -), 14.35 (q, 2C, J = 126 Hz, -N = C (CH 3) -CH = C (CH 3 ) -N-), 11.51 (q, 2C, J = 128 Hz, -N = C (CH 3) -CH = C (CH 3) -N-).

IR (solid neat; cm ^-1 ): 3745 (m), 2906 (m), 2845 (m), 1747 (m), 1693 (m), 1650 (m), 1549 1379 (s), 1332 (s), 1294 (s), 1251 (m), 1178 (m), 1045 (s), 960 (m), 799 (s), 689 (s), 634 (m).

Empirical formula C ₁₉ H ₃₁ Cl ₂ N ₅ Zn Formula weight 465.76 Crystal system Monoclinic Space group P2 (1) / c Unit cell dimensions a = 8.8382 (5) A b = 17.746 (1) A c = 14.2916 (8) Å Volume 2218.1 (2) Å ³ Z 4 Calculated density 1.395 g / cm < ³ > Absorption coefficient 1.362 mm ^-1 F (000) 976 Crystal size 0.26 x 0.17 x 0.12 mm ³ Theta range for data collection 1.84 to 28.28 Index ranges 11? H? 11, -23? K? 22, -19? Reflections collected 16398 Refinement method Full-matrix least-squares on F ² Data / restraints / parameters 5498/0/248 Goodness-of-fit on F ² 1.003 Final R indices [I > 2? (I)] R ₁ = 0.0480, w R ₂ = 0.0898 R indices (all data) R ₁ = 0.1162, w R ₂ = 0.1205 Abs. Largest diff. peak and hole 0.632 and -0.613 e. Å ^-3

Bond lengths Zn (1) -N (4) 2.054 (3) Zn (1) -N (1) 2.050 (3) Zn (1) - Cl (1) 2.253 (1) Zn (1) - Cl (2) 2.219 (1) N (1) -C (1) 1.337 (5) N (1) - N (2) 1.371 (4) N (2) -C (4) 1.359 (4) Bond angles N (4) -Zn (1) -N (1) 107.8 (1)  N (4) -Zn (1) -Cl (2) 116.04 (8)  N (1) -Zn (1) -Cl (2) 108.63 (9)  N (4) -Zn (1) -Cl (1) 101.91 (8)  N (1) -Zn (1) -Cl (1) 104.60 (8)  Cl (2) -Zn (1) -Cl (1) 116.90 (4) C (1) -N (1) -N (2) 105.8 (3) C (1) -N (1) -Zn (1) 125.7 (2) N (2) -N (1) -Zn (1) 127.6 (2)

Zinc complex Sample 3: [L ₃ ZnBr ₂ ]

A solution of the ligand [L ₃ ] (0.249 g, 1.00 mmol) dissolved in 10 ml of ethanol and a solution of ZnBr ₂ (0.225 g, 1.00 mmol) in 10 ml of ethanol were mixed and reacted at 25 ° C for 24 hours. The reaction solvent was removed by vacuum decompression drying, and 30 ml of cold ethanol was washed three times, and then washed three times with 30 ml of hexane to obtain a white solid compound. The yield was 0.404 g (85.2%).

Analysis calculated for C ₁₂ H ₁₉ Br ₂ N ₅ OZn: C, 30.4%, H, 4.04%, N, 14.7%. Found: C, 30.6%, H, 4.06%, N, 14.7%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 7.81 (d, 2H, J = 2.4 Hz, -N = CH-CH = CH-N-), 7.51 (d, 2H, J = 2.0 Hz, -N = CH-CH = CH-N- ), 6.29 (t, 2H, J = 2.4 Hz, -N = CH-CH = CH-N-), 5.10 (s, 4H, -N-CH 2 -N-) , 3.18 (t, 2H, J = 6.4 Hz, CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 3.13 (s, 3H, CH 3 -O-CH 2 -CH 2 -CH 2 - N-), 2.56 (t, 2H , J = 6.8 Hz, CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 1.60-1.53 (m, 2H, CH 3 -O-CH 2 -CH ₂ -CH ₂ -N-).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 139.96 (d, 2C, J = 184 Hz, -N = CH-CH = CH-N-), 131.72 (d, 2C, J = 187 Hz, -N = CH-CH = CH-N- ), 106.10 (d, 2C, J = 186 Hz, -N = CH-CH = CH-N-), 69.83 (t, 1C, J = 139 Hz, -CH 3 - _{O-CH 2 -CH 2 -CH 2} -N-), 68.34 (t, 2C, J = 150 Hz, -N-CH 2 -N-), 58.12 (q, 1C, J = 139 Hz, CH 3 - O- CH ₂ -CH ₂ -CH ₂ -N-), 46.64 (t, 1C, J = 138 Hz, CH ₃ -O-CH ₂ -CH ₂ -CH ₂ -N-), 26.90 _{J = 125 Hz, CH 3 -O} -CH 2 -CH 2 -CH 2 -N-).

IR (solid neat; cm ^-1 ): 3110 (w), 1793 (w), 1734 (w), 1624 (w), 1521 (m), 1448 (S), 1150 (m), 1172 (m), 1151 (s), 1102 (m), 1072 (w), 986 (w), 852 (w), 782 645 (m), 611 (s).

Zinc complex Sample 4: [L ₄ ZnCl ₂ ]

A solution of the ligand [L ₄ ] (0.305 g, 1.00 mmol) dissolved in 10 ml of ethanol and a solution of ZnCl ₂ (0.136 g, 1.00 mmol) in 10 ml of ethanol were mixed and reacted at 25 ° C for 24 hours. The reaction solvent was removed by vacuum decompression drying, and 30 ml of cold ethanol was washed three times, and then washed three times with 30 ml of hexane to obtain a white solid compound. The yield was 0.95 g (89.6%).

Analysis calculated for C ₁₆ H ₂₇ Cl ₂ N ₅ Zn: C, 43.5%, H, 6.16%, N, 15.8%. Found: C, 43.2%, H, 6.15%, N, 15.8%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 6.21 (s, 2H, -N = C (CH 3) -CH = C (CH 3) -N-), 5.12 (s, 4H, -N-CH _{2 -N-), 3.43 (t,} 2H, J = 6.0 Hz, CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 3.28 (s, 3H, CH 3 -O-CH 2 -CH _2- CH ₂ -N-), 2.77 (t, 2H, J = 7.2 Hz, -CH ₃ -O-CH ₂ -CH ₂ -CH ₂ -N-) _{CH 3) -CH = C (CH} 3) -N-), 2.45 (s, 6H, -N = C (CH 3) -CH = C (CH 3) -N-), 1.85-1.79 (m, 2H , -CH ₃ -O-CH ₂ -CH ₂ -CH ₂ -N-).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 151.47 (s, 2C, -N = C (CH 3) -CH = C (CH 3) -N-), 143.98 (s, 2C, -N = C _{(CH 3) -CH = C (} CH 3) -N-), 108.30 (d, 2C, J = 176 Hz, -N = C (CH 3) -CH = C (CH 3) -N-), 69.94 (t, 1C, J = 134 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 61.75 (t, 2C, J = 152 Hz, -N-CH 2 -N-), 58.14 (q, 1C, J = 138 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 46.90 (t, 1C, J = 128 Hz, -CH 3 -O-CH 2 - _{CH 2 -CH 2 -N-), 27.71} (t, 1C, J = 125 Hz, -CH 3 -O-CH 2 -CH 2 -CH 2 -N-), 13.59 (q, 2C, J = 128 Hz _{, -N = C (CH 3)} -CH = C (CH 3) -N-), 10.75 (q, 2C, J = 128 Hz, -N = C (CH 3) -CH = C (CH 3) - N-).

IR (solid neat; cm ^-1 ): 3274 (m), 2926 (w), 2857 (w), 1570 (m), 1527 (m), 1421 (s), 1385 1280 (s), 1178 (m), 1161 (s), 1047 (s), 992 (m), 895 (w), 809 (s), 711 (s), 662 593 (w).

Zinc complex Sample 5: [L ₅ ZnCl ₂ ]

A solution of ligand [L ₅ ] (0.332 g, 1.00 mmol) dissolved in 10 ml of ethanol and a solution of ZnCl ₂ (0.136 g, 1.00 mmol) in 10 ml of ethanol were mixed and reacted at 25 ° C for 24 hours. The reaction solvent was removed by vacuum decompression drying, and 30 ml of cold ethanol was washed three times, and then washed three times with 30 ml of hexane to obtain a white solid compound. The yield was 0.395 g (84.4%).

Analysis calculated for C ₁₄ H ₁₄ BrCl ₂ N ₅ Zn: C, 35.9%; H, 3.01%; N, 14.9%. Found: C, 36.1%; H, 2.97%; N, 14.7%.

_{^{1 H-NMR (CDCl 3,}} 400 MHz): δ 7.85 (d, 2H, J = 2.4 Hz, -N = CH-CH = CH-N-), 7.52 (d, 2H, J = 2.0 Hz, -N = CH-CH = CH-N- ), 7.35 (d, 2H, J = 8.8 Hz, m -NC 6 H 4 Br-), 7.18 (d, 2H, J = 9.2 Hz, o -NC 6 H 4 Br -), 6.27 (t, 2H , J = 2.4 Hz, -N = CH-CH = CH-N-), 5.91 (s, 4H, -N-CH 2 -N-).

_{^{13 C-NMR (CDCl 3,}} 100 MHz): δ 144.81 (s, 1C, ipso -NC 6 H 4 Br-), 139.67 (d, 2C, J = 181 Hz, -N = CH-CH = CH-N -), 131.89 (d, 2C , J = 165 Hz, m -NC 6 H 4 Br-), 130.19 (d, 2C, J = 184 Hz, -N = CH-CH = CH-N-), 116.68 ( d, 2C, J = 155 Hz , o -NC 6 H 4 Br-), 111.37 (s, 1C, p -NC 6 H 4 Br-), 106.12 (d, 2C, J = 186 Hz, -N = CH -CH = CH-N-), 66.09 (t, 2 C, J = 152 Hz, -N-CH ₂ -N-).

IR (solid neat; cm ^-1 ): 3113 (w), 3099 (w), 1591 (w), 1496 (m), 1467 (w), 1422 (m), 1404 1320 (m), 1207 (s), 1193 (s), 1161 (s), 1072 (s), 875 (m), 817 (s), 765 (s), 736 (s), 612 (m).

Manufacture of polymers

Preparation of polylactide 1:

Methyllithium (MeLi, 1 mmole, 0.5 ml) was injected into a solution of the above prepared zinc complex sample 1 [L ₁ ZnCl ₂ ] (0.2 g, 0.5 mmole) in tetrahydrofuran Lt; / RTI >

Similarly, lactide (0.9 g) was dissolved in methylene chloride (5 ml) under an argon atmosphere, and the activated catalyst (1 ml) prepared above was then introduced and stirred at -50 ° C for 24 hours. After 24 hours, distilled water (2 ml) was added to the obtained reaction product, and the reaction was terminated. Nucleating agent (10 ml) was added to precipitate the polymer. The precipitate was separated under reduced pressure and washed with methanol (50 ml) three times. This was dried under reduced pressure to obtain 0.55 g of the final polymer. NMR was used to confirm that the conversion yield was 14.5%. The Mw of the obtained polylactide as the final polymer was 5.542 (g / mol) × 10 ³ , the Mn was 4.744 (g / mol) × 10 ³ , and the Pr (heterotacticity) was 0.79.

Preparation of polylactide 2:

The polylactide was prepared through substantially the same procedure as in Preparation 1 of polylactide except that the zinc complex sample 2 [L ₂ ZnCl ₂ ] prepared above was used as a catalyst. 0.30 g of polylactide was obtained, and NMR was used to confirm that conversion yield was up to 9.0%. The Mw and the Mn of the obtained polylactide as the final polymer were 4.615 (g / mol) × 10 ³ and 4.170 (g / mol) × 10 ³ , respectively, and the Pr (heterotacticity) was 0.80.

Preparation of polylactide 3:

A polylactide was prepared through substantially the same procedure as in Preparation 1 of polylactide except that the zinc complex sample 3 [L ₃ ZnCl ₂ ] prepared above was used as a catalyst. 3.40 g of polylactide was obtained and it was confirmed by NMR that conversion yield was 100%. The polylactide as the final polymer thus obtained had Mw of 24.85 (g / mol) × 10 ³ , Mn of 19.2 (g / mol) × 10 ³ , and Pr (heterotacticity) of 0.87.

Preparation of polylactide 4:

A polylactide was prepared through substantially the same procedure as in Preparation 1 of polylactide except that the zinc complex sample 4 [L ₄ ZnCl ₂ ] prepared above was used as a catalyst. 3.46 g of polylactide was obtained and it was confirmed by NMR that conversion yield was 100%. The Mw and the Mn of the obtained polylactide were 28.92 (g / mol) × 10 ³ and 21.73 (g / mol) × 10 ³ , respectively, and Pr (heterotacticity) was 0.91.

Preparation of polylactide 5:

A polylactide was prepared through substantially the same procedure as in Preparation 1 of polylactide except that the zinc complex sample 5 [L ₅ ZnCl ₂ ] prepared above was used as a catalyst. 2.43 g of polylactide was obtained and it was confirmed by NMR that conversion yield was 83.8%. The final polymer, polylactide, had a Mw of 15.00 (g / mol) × 10 ³ , a Mn of 13.77 (g / mol) × 10 ³ , and a Pr (heterotacticity) of 0.91.

Preparation of polylactide 6:

The procedure was substantially the same as that of Preparation 1 of polylactide except that the reaction temperature of the activated catalyst and lactide was changed to 25 ° C to obtain 0.21 g of polylactide. Using NMR, conversion rate of 100% Respectively. The obtained polylactide had Mw of 31.80 (g / mol) × 10 ³ , Mn of 25.30 (g / mol) × 10 ³ , and Pr (heterotacticity) of 0.54.

Preparation of polylactide 7:

0.67 g of polylactide was obtained by carrying out substantially the same process as Preparation 1 of polylactide except that the reaction temperature of the activated catalyst and lactide was set to -25 ° C and NMR of the conversion product was 100% Respectively. The obtained polylactide had Mw of 35.89 (g / mol) × 10 ³ , Mn of 28.13 (g / mol) × 10 ³ , and Pr (polylactide) of 0.87.

Preparation of polylactide 8, 9

Substantially the same process as that of Preparation 2 of polylactide was carried out except that the reaction temperature of the activated catalyst and lactide was set to 25 ° C and -25 ° C and it was confirmed that conversion rate of 100% was obtained using NMR .

When the reaction was carried out at 25 ° C, 0.17 g of polylactide was obtained. The Mw of the obtained polylactide was 34.84 (g / mol) × 10 ³ and the Mn was 26.64 (g / mol) × 10 ³ . City) was 0.59.

(G / mol) x 10 < ³ > and Mn was 27.33 (g / mol) x 10 < ^{3 &} gt ;, and Pr (hetero- Lacticity) was 0.91.

Production of polylactide 10, 11

Substantially the same process as that of Production 3 of polylactide was carried out except that the reaction temperature of activated catalyst and lactide was set to 25 ° C and -25 ° C and it was confirmed that up to 100% conversion was obtained using NMR .

When the reaction was carried out at 25 ° C, 0.14 g of polylactide was obtained. The Mw of the obtained polylactide was 35.66 (g / mol) × 10 ³ and the Mn was 27.23 (g / mol) × 10 ³ . City) was 0.57.

(G / mol) x 10 < ³ > and Mn was 21.86 (g / mol) x 10 < ^{3 &} gt ;, and Pr (hetero- Lacticity) was 0.87.

Preparation of polylactide 12, 13

Substantially the same process as that of Preparation 4 of polylactide was carried out except that the reaction temperature of the activated catalyst and lactide was changed to 25 캜 and -25 캜, and it was confirmed that conversion rate of up to 100% was obtained using NMR .

(G / mol) x 10 < ³ > and Mn was 14.89 (g / mol) x 10 < ^{3 &} gt ;, and Pr (lactaldehyde) was reacted at 25 ° C to obtain 0.31 g of polylactide. City) was 0.71.

When the reaction was carried out at -25 ° C, 0.97 g of polylactide was obtained. The Mw of the resulting polylactide was 27.48 (g / mol) × 10 ³ and the Mn was 20.98 (g / mol) × 10 ³ . Lacticity) was 0.87.

Preparation of polylactide 14, 15

Substantially the same process as that of Preparation 5 of polylactide was carried out except that the reaction temperature of activated catalyst and lactide was changed to 25 ° C and -25 ° C and NMR was used to confirm that conversion yield was 100% .

(G / mol) x 10 < ³ > and Mn was 22.51 (g / mol) x 10 < ^{3 &} gt ;, and Pr (lactaldehyde City) was 0.74.

When the reaction was carried out at -25 캜, 0.97 g of polylactide was obtained. The Mw of the obtained polylactide was 28.31 (g / mol) × 10 ³ and the Mn was 21.84 (g / mol) × 10 ³ . Lacticity) was 0.87.

The results of polymerization according to the conditions of Preparation 1 to 15 of the polylactide can be summarized as shown in Table 3 below.

(Conditions: [Initiator] = 0.0625 mmol, [rac-LA] / [Initiator] = 100, 5 mL of Solvent (CH ₂ Cl ₂ ), polymerization time = 24 h)

Zinc complex
division T
(Temperature, ° C) Conversion
(Conversion rate,%) Mn
(g / mol) x 10 < ³ > Mw
(g / mol) x 10 < ³ > PDI Pr [L _One ZnCl ₂ ]  25 100 25.30 31.80 1.25 0.54 -25 100 28.13 35.89 1.27 0.87  -50 14.5 4.744 5.542 1.16 0.79 [L ₂ ZnCl ₂ ]  25 100 26.64 34.84 1.30 0.59 -25 100 27.33 35.61 1.30 0.91 -50 9.00 4.170 4.615 1.10 0.80 [L ₃ ZnCl ₂ ]  25 100 27.23 35.66 1.30 0.57 -25 100 21.86 28.92 1.32 0.87 -50 100 19.23 24.85 1.29 0.87 [L ₄ ZnCl ₂ ]  25 100 14.89 18.65 1.25 0.71 -25 100 20.98 27.48 1.30 0.87 -50 100 21.73 28.92 1.33 0.91 [L ₅ ZnCl ₂ ] 25 100 22.51 28.42 1.26 0.74 -25 100 21.84 28.31 1.29 0.87 -50 83.8 13.77 15.00 1.08 0.91

Referring to Table 3, when the polylactide was produced by reacting each of the zinc complex samples 1 to 5 at 25 ° C, -25 ° C, and -50 ° C, in the case of the zinc complex samples 1 and 2, The transition from the tide to the polymer is very low at 14.5% or less. However, when the zinc complex samples 3 to 5 are used, it can be confirmed that at least 83.8% and substantially up to 100% are exhibited. Especially, at 25 ° C or -25 ° C, it can be seen that all the cases using the zinc complex samples 1 to 5 exhibit a conversion rate of 100%. That is, when the zinc complex according to the present invention is used for the polymerization of lactide for the production of polylactide, it can be confirmed that the monomer does not remain and is converted to 100% polymer.

In the paper Polyhedron 29 (2010) 2404-2408, it has been disclosed that a zinc complex represented by the following formula (3) is used in the polymerization of rac-lactide to prepare polylactide. However, when the zinc complex is used, The conversion rate is only about 93% at the maximum, and the conversion rate is only 52% at -20 ° C.

(3)

In addition, when the polylactide is prepared using the zinc complex represented by the above formula (3) in the document Polyhedron 29 (2010) 2404-2408, the heterotacticity is only 0.5 to 0.6.

On the other hand, as in the case of the zinc complex represented by Formula 1 according to the present invention, Ar (Ar represents a cycloalkyl group, an alkoxy group, or a halogen group, and L represents - (CH ₂ ) _y - And y is an integer of 1 to 5) or an arylene group, it is possible to maximize the conversion and the heterotacticity of the zinc complex represented by the above formula (3) even at -20 캜 or lower.

2 is a view showing a homonuclear decoupled ¹ H-NMR spectrum according to the reaction temperature when the polylactide is produced using the zinc complex sample 4 of the present invention.

In Fig. 2, " i " of the heterotacticity shown in the peaks appearing in each spectrum represents isotactic, "s " represents syndiotactic, and iii, iis, sii, sis and isi each represent the following structures 1 to 5 .

[Structure 1]

[Structure 2]

[Structure 3]

[Structure 4]

[Structure 5]

2, (a) shows the case where the reaction temperature is 25 ° C, (b) shows the case where the reaction temperature is -25 ° C and (c) shows the case where the reaction temperature is -50 ° C. , When the temperature is lowered to -25 캜 and -50 캜 at room temperature (25 캜), the content of the structure represented by sii, iss and iii is decreased and the content of the structure represented by sis and isi is increased.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims. It can be understood that it is possible.

Claims (15)

N, N-bis-spiazolyl ligand and zinc, represented by the following general formula (1)
Zinc complex;
[Chemical Formula 1]

In the formula (1), Ar represents a cycloalkyl group, an alkoxy group or a halogen group, L represents - (CH ₂ ) _y - (wherein y is an integer of 1 to 5) or an arylene group, and R ₁ to R ₄ each independently Represents hydrogen or an alkyl group, and X represents a halogen group.
The method according to claim 1,
Ar in formula (1)
A cycloalkyl group having 5 to 7 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or a halogen group.
Zinc complex.
The method according to claim 1,
(1) is represented by the following general formula (1a) or (1b)
Zinc complex;
[Formula 1a]

[Chemical Formula 1b]

The method according to claim 1,
(1) is represented by the following formula (1c) or (1d).
Zinc complex;
[Chemical Formula 1c]

≪ RTI ID = 0.0 &

The method according to claim 1,
(1) is represented by the following formula (1e)
Zinc complex;
[Formula 1e]

A zinc complex according to claim 1,
A catalyst for the polymerization of monomers having a cyclic ester group.
The method according to claim 6,
Characterized in that the zinc complex has catalytic activity by means of a methyllithium lithium bromide complex.
A catalyst for the polymerization of monomers having a cyclic ester group.
The method according to claim 6,
The zinc complex
Glycolide (1,4-dioxane-2,5-dione), gamma-caprolactone (

2-oxepanone, L-lactide, (3S) -cis-3,6-dimethyl-1,4-dioxane-2,5-dione and lactide -Dimethyl-1,4-dioxane-2,5-dione).
A catalyst for the polymerization of monomers having a cyclic ester group.
Mixing the zinc complex according to claim 1 with a monomer having a cyclic ester group to form a polymer.
≪ / RTI >
10. The method of claim 9,
In the step of forming the polymer
Wherein the polymerization reaction is carried out at a temperature of from -50 占 폚 to 25 占 폚.
≪ / RTI >
10. The method of claim 9,
In the step of forming the polymer
Characterized in that the conversion of monomer to polymer is 100% at -25 占 폚 to 25 占 폚.
≪ / RTI >
10. The method of claim 9,
In the step of forming the polymer
Characterized in that the polymer prepared at -50 DEG C to -25 DEG C has a heterotacticity of 0.7 to 0.95.
≪ / RTI >
10. The method of claim 9,
The monomer
Glycolide (1,4-dioxane-2,5-dione), gamma-caprolactone, 2-oxepanone, L-lactide (3S) -cis-3,6 dimethyl-1,4-dioxane-2,5-dione) and lactide (3,6-dimethyl-1,4-dioxane-2,5-dione) ,
≪ / RTI >
10. The method of claim 9,
Further comprising mixing the zinc complex with a cocatalyst to activate the zinc complex before mixing the zinc complex with the monomer,
Characterized in that the activated zinc complex is used as a catalyst for the polymerization of the monomer.
≪ / RTI >
15. The method of claim 14,
The cocatalyst
≪ RTI ID = 0.0 > methyllithium < / RTI > lithium bromide complex.
≪ / RTI >

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