METAL COMPLEX COMPOUND, AND METAL NANOSTRUCTURE AND CATALYST COMPOSITION COMPRISING THE SAME

Abstract

The present invention relates to a metal complex compound which are prepared in the form of a metal nanostructure having various stereo structures and thus can be used as a catalyst or the like having an excellent activity in preparing a polyalkylene carbonate resin and the like, and a metal nanostructure and a catalyst composition comprising the same. The metal complex compound comprises a plurality of linear inorganic coordination polymer chains having a form in which an oxalic acid is coordinated and linked to a transition metal and the plurality of polymer chains are linked to each other via a predetermined neutral ligand.

Claims

1. A metal complex compound comprising a plurality of linear inorganic coordination polymer chains containing a repeating unit represented by the following Chemical Formula 1, wherein the plurality of polymer chains are linked to each other via a neutral ligand coordinately bonded to the central metal M of Chemical Formula 1. ##STR00008## in the Chemical Formula 1, M is at least one transition metal element selected from the group consisting of Fe, Ni, Zn and Co, n represents an integer of 30 to 1,000,000, a solid line represents a covalent bond, a dotted line represents a coordinate bond, and * represents a linking moiety.

2. The metal complex compound of claim 1, wherein the neutral ligand is a compound including a plurality of oxygen-, sulfur-, phosphorus- or nitrogen-containing functional groups capable of coordinating to the M; or a ring-containing compound including a plurality of one or more hetero elements selected from the group consisting of oxygen, sulfur, phosphorus and nitrogen.

3. The metal complex compound of claim 2, wherein the oxygen-, sulfur-, phosphorus- or nitrogen-containing functional group is selected from the group consisting of an oxo group (—O—), a hydroxyl group, an amine group, a carboxyl group (—COOH), a thiol group, a phosphine group (—PR2 and the like, wherein R is an alkyl group or an aryl group), a nitrogen-containing heterocyclic ring, a sulfur-containing heterocyclic ring, a phosphorus-containing heterocyclic ring and an oxygen-containing heterocyclic ring.

4. The metal complex compound of claim 2, wherein the neutral ligand is at least one selected from water (H2O), an alkylene diol having 2 to 5 carbon atoms, an alkylene diamine having 2 to 5 carbon atoms, a hydroxy alkyl amine having 2 to 5 carbon atoms, a dioxane-based compound, a morpholine-based compound, a piperazine-based compound, a pyrazine-based compound, a 4,4′-dipyridyl-based compound, a phenoxazine-based compound, an aminophenol-based compound, a hydroxyquinoline-based compound, a phenylenediamine-based compound, a hydroxybenzoic acid-based compound, an alkylene dithiol having 2 to 5 carbon atoms, a mercapto alkanol having 2 to 5 carbon atoms, a thiophenol-based compound, an aminothiophenol-based compound, a diphosphino compound having 2 to 5 carbon atoms and an aminobenzoic acid-based compound.

5. The metal complex compound of claim 1, comprising a repeating unit represented by Chemical Formula 2 below: ##STR00009## in the Chemical Formula 2, M, n, the solid line, the dotted line and * are as defined in the Chemical Formula 1, and A is a neutral ligand coordinately bonded to the central metal M.

6. A metal nanostructure comprising the metal complex compound of claim 1.

7. The metal nanostructure of claim 6, having zero-dimensional to three-dimensional structures.

8. A method for preparing the metal nanostructure of claim 6 comprising reacting a salt of a transition metal M, an oxalic acid and a neutral ligand, in a solvent.

9. The method for preparing the metal nanostructure of claim 8, wherein the salt of a transition metal M is selected from the group consisting of an acetate salt, a halogen salt, a sulfate salt, a nitrate salt and a sulfonate salt.

10. The method for preparing the metal nanostructure of claim 8, wherein the solvent is at least one selected from the group consisting of methylene chloride, ethylene dichloride, trichloroethane, tetrachloroethane, chloroform, acetonitrile, propionitrile, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl acetamide, nitromethane, 1,4-dioxane, hexane, toluene, tetrahydrofuran, methyl ethyl ketone, methylamine ketone, methyl isobutyl ketone, acetone, cyclohexanone, trichloroethylene, methyl acetate, vinyl acetate, ethyl acetate, propyl acetate, butyrolactone, caprolactone, nitropropane, benzene, styrene, xylene, methyl propasol, ethylene glycol, 1,2-propanediol and 1,3-propanediol.

11. The method for preparing the metal nanostructure of claim 8, the step of reacting the salt of a transition metal, the oxalic acid and the neutral ligand is performed at a temperature of 0° C. to 250° C.

12. A catalyst composition comprising the metal nanostructure of claim 6.

13. A method for preparing a polyalkylene carbonate resin comprising polymerizing a monomer including an epoxide and carbon dioxide in the presence of the catalyst composition of claim 12.

14. The method for preparing a polyalkylene carbonate resin of claim 13 which is carried out by solution polymerization in an organic solvent.

15. A metal nanostructure comprising the metal complex compound of claim 2.

16. A metal nanostructure comprising the metal complex compound of claim 3.

17. A metal nanostructure comprising the metal complex compound of claim 4.

18. A metal nanostructure comprising the metal complex compound of claim 5.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0061] FIGS. 1a to 2d show EDS, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 1.

[0062] FIGS. 2a to 2d show EDS, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 2.

[0063] FIGS. 3a to 3c show FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 3.

[0064] FIGS. 4a to 4c show EDS and FT-IR analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 4.

[0065] FIGS. 5a to 5d show EDS, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 5.

[0066] FIGS. 6a to 6d show EDS, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 6.

[0067] FIGS. 7a to 7d show EDS, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 7.

[0068] FIGS. 8a to 8d show XRD, FT-IR and TGA analysis results, and electron micrographs of the metal complex compound and metal nanostructure of Example 8.

EXAMPLES

[0069] Hereinafter, preferred embodiments are provided to help understanding of the present invention, but the embodiments are only for illustrative purposes, and the scope of the invention is not intended to be limited by these Examples.

Example 1: Preparation of Metal Complex Compound (ZnOx; Dripping in Acetonitrile) and Metal Nanostructure

[0070] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, 0.183 g (0.001 mol) of zinc acetate was added and dissolved in the solution with stirring. 10 mL of acetonitrile was then added to another 50 mL round bottom flask, and the above solution was added dropwise, followed by stirring for 2 hours. Thereafter, a catalyst precipitate was obtained by centrifugation, washed with ethanol by centrifugation, and dried under vacuum at room temperature.

[0071] Thereby, the metal complex compound of Example 1 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 1a to 1c, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 1 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). Further, it was confirmed from the TGA analysis result that the first weight reduction of 21% corresponds to dihydrate, the second weight reduction corresponds to CO.sub.2, CO (from oxalate), and the remaining weight reduction corresponds to ZnO.

[0072] In addition, the structure of the metal complex compound of Example 1 was analyzed by electron micrographs and was shown in FIG. 1d. With reference to FIG. 1d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

Example 2: Preparation of Metal Complex Compound (ZnOx; TEA3.3) and Metal Nanostructure

[0073] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, zinc sulfate heptahydrate and 0.460 mL (0.0033 mol) of triethylamine were added, followed by stirring for 2 hours. Thereafter, a catalyst precipitate was obtained by centrifugation, washed with ethanol by centrifugation, and dried under vacuum at room temperature.

[0074] Thereby, the metal complex compound of Example 2 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 2a to 2c, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 2 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). Further, it was confirmed from the TGA analysis result that the weight reduction seen at the initial 60° C. is the impurity resulting from the surrounding environment such as moisture in the TGA machine, and thereafter the weight reduced at 243° C. assigns to ethylene glycol.

[0075] In addition, the structure of the metal complex compound of Example 1 was analyzed by electron micrographs and was shown in FIG. 2d. With reference to FIG. 2d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

Example 3: Preparation of Metal Complex Compound (ZnOx; TEA 2.1) and Metal Nanostructure

[0076] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, 0.288 g (0.001 mol) of zinc sulfate heptahydrate and 0.294 mL (0.0021 mol) of triethylamine were added, followed by stirring for 2 hours. Thereafter, a catalyst precipitate was obtained by centrifugation, washed with ethanol by centrifugation, and dried under vacuum at room temperature.

[0077] Thereby, the metal complex compound of Example 3 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA. Among the confirmation results thereof, the FT-IR and TGA analysis results were shown in FIGS. 3a and 3b, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 3 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). Further, it was confirmed from the TGA analysis result that the weight reduction of H.sub.2O was shown at 134° C., the weight reduction of EG was shown at 233° C., and thereafter the weight of CO.sub.2 and CO were reduced. Referring to the results of the FT-IR analysis, it was confirmed that a metal complex compound as shown in Chemical Formula 2 having H.sub.2O and EG ligand was formed.

[0078] In addition, the structure of the metal complex compound of Example 3 was analyzed by electron micrographs and was shown in FIG. 3c. With reference to FIG. 3c, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

Example 4: Preparation of Metal Complex Compound (ZnOx; TOEA3.3) and Metal Nanostructure

[0079] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, 0.288 g (0.001 mol) of zinc sulfate heptahydrate and 0.438 mL (0.0033 mol) of triethylamine were added, followed by stirring for 2 hours. Thereafter, a catalyst precipitate was obtained by centrifugation, washed with ethanol by centrifugation, and dried under vacuum at room temperature.

[0080] Thereby, the metal complex compound of Example 4 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA. Among the confirmation results thereof, the EDS and FT-IR analysis results were shown in FIGS. 4a and 4b, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 4 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). Further, referring to the TGA analysis result, it was confirmed that a metal complex compound as shown in Chemical Formula 2 having H.sub.2O and EG ligand was formed.

[0081] In addition, the structure of the metal complex compound of Example 4 was analyzed by electron micrographs and was shown in FIG. 4c. With reference to FIG. 4c, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

Example 5: Preparation of Metal Complex Compound (ZnOx; TOEA2.1) and Metal Nanostructure

[0082] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, 0.288 g (0.001 mol) of zinc sulfate heptahydrate and 0.278 mL (0.0021 mol) of triethylamine were added, followed by stirring for 2 hours. Thereafter, a catalyst precipitate was obtained by centrifugation, washed with ethanol by centrifugation, and dried under vacuum at room temperature.

[0083] Thereby, the metal complex compound of Example 5 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 5a to 5c, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 5 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). In the TGA analysis results, the weight reduction of H.sub.2O was shown at 133° C., the weight reduction of EG was shown at 214° C., and thereafter the weight of CO.sub.2 and CO was appeared to be reduced.

[0084] In addition, the structure of the metal complex compound of Example 5 was analyzed by electron micrographs and was shown in FIG. 5d. With reference to FIG. 5d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

Example 6: Preparation of Metal Complex Compound (Ni-ZnOx; Plate) and Metal Nanostructure

[0085] All reactions were carried out in the glove box. Oxalic acid (0.090 g) was dissolved in anhydrous ethylene glycol (15 mL) and then stirred at 200 rpm. Zn sulfate (0.081 g), Nickel chloride (0.065 g) and Molecular sieve 3A (1.0 g) were added to the solution, and the reaction was progressed while observing until oxalic acid was completely dissolved. After that, the solution was stirred for another 2 hours, and then the precipitate formed was centrifuged. The separated precipitate was washed three times with anhydrous THF to give a metal complex compound of Example 6 in a yield of 0.0472 g.

[0086] Thereby, the metal complex compound of Example 6 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 6a to 6c, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 6 has a structure as shown in Chemical Formula 2 (however, including Ni:Zn at a weight ratio of about 1:5 as a metal element). In particular, referring to the FT-IR analysis result, it was confirmed that a metal complex compound as shown in Chemical Formula 2 having H.sub.2O and EG ligand was formed.

[0087] In addition, the structure of the metal complex compound of Example 6 was analyzed by electron micrographs and was shown in FIG. 6d. With reference to FIG. 6d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures, especially a plate shape.

Example 7: Preparation of Metal Complex Compound (Ni-ZnOx; Rod) and Metal Nanostructure

[0088] Oxalic acid (0.090 g) was dissolved in anhydrous ethylene glycol (15 mL) and then stirred at 200 rpm. When Zinc sulfate heptahydrate (0.114 g) and Nickel chloride hydrate (0.065 g) were added, the reaction was progressed while observing until oxalic acid was completely dissolved. After that, the solution was stirred for another 2 hours, and then the precipitate formed was centrifuged. The separated precipitate was washed three times with ethanol to give a metal complex compound of Example 7.

[0089] Thereby, the metal complex compound of Example 7 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 7a to 7c, respectively. It was confirmed through the EDS elemental analysis result and the FT-IR spectrum that the metal complex compound of Example 7 has a structure as shown in Chemical Formula 2 (however, including Ni:Zn at a weight ratio of about 1:5 as a metal element). In particular, referring to the FT-IR analysis result, it was confirmed that a metal complex compound as shown in Chemical Formula 2 having H.sub.2O and EG ligand was formed.

[0090] In addition, the structure of the metal complex compound of Example 7 was analyzed by electron micrographs and was shown in FIG. 7d. With reference to FIG. 7d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures, especially a rod shape.

Example 8: Preparation of Metal Complex Compound (CoOx) and Metal Nanostructure

[0091] In a 50 mL round bottom flask, 0.903 g (0.001 mol) of oxalic acid was added to 15 mL of ethylene glycol and dissolved with stirring for 20 minutes. Then, 0.001 mol of cobalt sulfate (CoSO.sub.4) was added to which 0.7 g of 3 Å molecular sieves was added, and then stirred and dissolved in the solution. Next, the mixture was stirred for 2 hours. Subsequently, the precipitate formed was precipitated, the solvent was separated and then washed again with 100 mL of THF three times and purified, followed by drying at 60° C. under vacuum.

[0092] Thereby, the metal complex compound of Example 8 was prepared, and the constituent elements and structure of the metal complex compound were analyzed and confirmed through EDS, FT-IR and TGA, and the confirmation results thereof were shown in FIGS. 8a to 8c, respectively. It was confirmed through the XRD peak position and the FT-IR spectrum that the metal complex compound of Example 8 has a structure as shown in Chemical Formula 2 (specifically, Chemical Formula 2A). It was confirmed from the TGA analysis result that the first weight reduction corresponds to ethylene glycol, the second weight reduction corresponds to CO.sub.2 and CO (from oxalate), and the remaining weight reduction corresponds to CoO.

[0093] In addition, the structure of the metal complex compound of Example 8 was analyzed by electron micrographs and was shown in FIG. 8d. With reference to FIG. 8d, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having various stereo structures.

[0094] Polymerization Example: Preparation of Polypropylene Carbonate Resin

[0095] First, in a glove box, 0.0182 g of catalyst (Examples 1 to 7) and 7.96 g of methylene chloride were added to a high-pressure reactor, and then 10.8 g of propylene oxide was added. Thereafter, the reactor was pressurized to 20 bar with carbon dioxide. The polymerization reaction was then carried out at 65° C. for 18 hours. After completion of the reaction, unreacted carbon dioxide and propylene oxide were removed together with dichloromethane, which is a solvent. The residual solids were completely dried and quantitated to determine the amount of polypropylene carbonate produced. The catalyst activity and yield according to the polymerization results are summarized in Table 1 below.

TABLE-US-00001 TABLE 1 Copolymerization of carbon dioxide and propylene oxide Product TON Ratio Product amount (g/g of PPC No. catalyst Co-catalyst sampling Solvent color (g) catalyst) and PC 1 Example 1 X Glove MC White 0.0384 2.11 86%:14% 0.0182 g box 6 mL 2 Example 2 X Glove MC White 0.0264 1.45 Non 0.0182 g box 6 mL analysis 3 Example 3 X Glove MC White 0.0351 1.99 49%:51% 0.0182 g box 6 mL 4 Example 4 X Glove MC White 0.0140 0.770 40%:60% 0.0182 g box 6 mL 5 Example 5 X Glove MC White 0.0236 1.30 Non 0.0182 g box 6 mL analysis 6 Example 6 X Glove MC White 0.0210 1.15 49%:51% 0.0182 g box 6 mL 7 Example 7 X Glove MC White 0.0347 1.91 48%:52% 0.0182 g box 6 mL

[0096] With reference to Table 1 above, it was confirmed that the metal complex compounds and the metal nanostructures of Examples 1 to 7 exhibited a polymerization activity in the polymerization reaction for preparing the polypropylene carbonate resin and thus can be suitably used as a catalyst.