LINEAR INORGANIC COORDINATION POLYMER, METAL COMPLEX COMPOUND, AND METAL NANOSTRUCTURE AND CATALYST COMPOSITION COMPRISING THE SAME

Abstract

The present invention relates to a linear inorganic coordination polymer and 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 linear inorganic coordination polymer comprises a repeating unit having a form in which a predetermined oxalic acid derivative is coordinately bonded to a transition metal, and the metal complex compound comprises a plurality of linear inorganic coordination polymer chains and has a structure in which the plurality of polymer chains are linked to each other via a predetermined neutral ligand.

Claims

1. A linear inorganic coordination polymer comprising a repeating unit represented by Chemical Formula 1 below: ##STR00009## In the Chemical Formula 1, M is at least one transition metal element selected from the group consisting of Fe, Ni, Zn and Co, Ra and Rb are each independently oxygen (—O—) or —NH—, Rc is oxygen or sulfur, with the proviso that Ra, Rb and Rc cannot all be oxygen, n represents an integer of 100 to 1,000,000, a solid line represents a covalent bond, a dotted line represents a coordinate bond, and * represents a linking moiety.

2. A metal complex compound which includes a plurality of linear inorganic coordination polymer chains containing the repeating units of Chemical Formula 1 of claim 1, wherein the plurality of polymer chains are linked to each other via a neutral ligand coordinately bonded to the central metal M of the Chemical Formula 1.

3. The metal complex compound of claim 2, 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.

4. The metal complex compound of claim 3, 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 (—PR.sub.2 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.

5. The metal complex compound of claim 3, wherein the neutral ligand is at least one selected from water (H.sub.2O), 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.

6. The metal complex compound of claim 2, comprising a repeating unit represented by Chemical Formula 2 below: ##STR00010## in the Chemical Formula 2, M, n, Ra, Rb, Rc, 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.

7. A metal nanostructure comprising the linear inorganic coordination polymer of claim 1.

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

9. A method for preparing the metal nanostructure of claim 7 comprising reacting a salt of a transition metal M, a compound represented by Chemical Formula 3 below and the neutral ligand, in a solvent, under heating:
Ra′—(C=Rc′)—(C=Rc′)—Rb′  [Chemical Formula 3] In the Chemical Formula 3, Ra′ and Rb′ are each independently —OH, —OM′ or —NH.sub.2, Rc′ is oxygen or sulfur, with the proviso that when Rc′ is oxygen, both Ra′ and Rb′ cannot be —OH or —OM′, and M′ is an alkali metal.

10. The method for preparing the metal nanostructure of claim 9, wherein the compound represented by Chemical Formula 3 includes oxamide, oxamate or thiooxalic acid.

11. The method for preparing the metal nanostructure of claim 9, 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.

12. The method for preparing the metal nanostructure of claim 9, 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, 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 and methyl propasol, ethylene glycol, 1,2-propanediol and 1,3-propanediol.

13. The method for preparing the metal nanostructure of claim 9, the step of reacting the salt of a transition metal, the compound represented by Chemical Formula 3 and the neutral ligand is performed under heating at room temperature to 250° C.

14. A catalyst composition comprising the metal nanostructure of claim 7.

15. 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 14.

16. The method for preparing a polyalkylene carbonate resin of claim 15 which is carried out by solution polymerization in an organic solvent.

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

Description

BRIEF DESCRIPTION OF DRAWINGS

[0069] FIG. 1 is an electron micrograph showing an example of a metal nanostructure having a one-dimensional structure (linear structure) including the metal complex compound according to another embodiment of the present invention.

[0070] FIGS. 2a to 2d show FT-IR analysis result, EDS elemental analysis result, TGA analysis result and electron micrographs of the metal complex compound and metal nanostructure of Example 1, respectively.

[0071] FIGS. 3a and 3b show FT-IR analysis result and electron micrographs of the metal complex compound and metal nanostructure of Example 2, respectively.

EXAMPLES

[0072] 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 Linear Inorganic Coordination Polymer, Metal Complex Compound (Zn-Oxamide) and Metal Nanostructure

[0073] After dispersing oxamide (0.088 g, 1 mmol) in ethylene glycol (15 mL), zinc sulfate heptahydrate (0.287 g, 1 mmol) was added, and then triethylamine (280 μL, 2 mmol) was added. After reacting the mixture for 3 hours, the precipitate was separated by centrifugation and washed three times with ethanol. Thereafter, the particles were removed with a membrane filter to obtain only the shape of a sheet.

[0074] 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. Among the confirmation results thereof, the result of the FT-IR analysis was shown in FIG. 2a, the result of the EDS analysis was shown in FIG. 2b, and the result of the TGA analysis was shown in FIG. 2c.

[0075] In the FT-IR analysis result of FIG. 2a, peaks corresponding to 3386 cm.sup.−1 (N—H), 3194 cm.sup.−1 (O—H), 1660 cm.sup.−1 (C═O), 1350 cm.sup.−1 (C—N), 1108 cm.sup.−1 (N—H), 800 cm.sup.−1 (C—C), 670 cm.sup.−1 (N—H) and 636 cm.sup.−1 (C═O) were confirmed, and it was confirmed that such a metal complex compound has a repeating unit structure of Chemical Formula 2. Further, the presence of Zn, which is the central metal element of the metal complex compound, was confirmed through the EDS analysis result of FIG. 2b. Furthermore, it was confirmed from the TGA analysis result of FIG. 2c that a weight reduction of 26% and 15% was shown in the temperature range of 100 to 250° C. and 250 to 450° C., respectively, whereby the presence of oxamide bound to the metal complex compound was confirmed. Moreover, it was confirmed from the TGA analysis result that the residual amount of 54% corresponds to the theoretical value of 54% of ZnO. That is, it was confirmed through the analysis results of FIGS. 2a to 2c that the metal complex compound of Example 1 has a structure shown in Chemical Formula 2.

[0076] In addition, the structure of the metal complex compound of Example 1 was analyzed by electron micrographs and is 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 a specific stereo structure, and that the metal nanostructure can be controlled to various three-dimensional structures and shapes compared to FIG. 1.

Example 2: Preparation of Linear Inorganic Coordination Polymer, Metal Complex Compound (Zn-Oxamate) and Metal Nanostructure

[0077] After dispersing oxamide (0.089 g, 1 mmol) in ethylene glycol (15 mL), zinc sulfate heptahydrate (0.287 g, 1 mmol) was added, and then triethylamine (280 μL, 2 mmol) was added. After reacting the mixture for 3 hours at room temperature, the precipitate was separated by centrifugation and washed three times with ethanol.

[0078] 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 FT-IR. The result of the FT-IR analysis is shown in FIG. 3a. In the FT-IR analysis result of FIG. 3a, peaks corresponding to 3415 cm.sup.−1 (N—H), 1630 cm.sup.−1 (—COO—), 1472 cm.sup.−1 (N—H), 849 cm.sup.−1 (C—C) and 490 cm.sup.−1 (Zn—O and Zn—N) were confirmed, and it was confirmed that such a metal complex compound has a repeating unit structure of Chemical Formula 2.

[0079] Further, the structure of the metal complex compound of Example 2 was analyzed by electron micrographs and was shown in FIG. 3b. With reference to FIG. 3b, it was confirmed that the metal complex compound was formed in the form of a metal nanostructure having a specific stereo structure, and that the metal nanostructure can be controlled to various three-dimensional structures and shapes compared to FIG. 1.

Polymerization Example: Preparation of Polypropylene Carbonate Resin

[0080] First, in a glove box, 0.0182 g of catalyst (Example 1 or Example 2) 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 Product TON (g/g Ratio PPC No. catalyst Co-catalyst sampling Solvent color amount (g) of catalyst) and PC 1 Example 1 X Glove MC White 0.0218 1.20 Non 0.0182 g box 6 mL analysis 2 Example 2 X Glove MC White 0.0246 1.35 Non 0.0182 g box 6 mL analysis

[0081] With reference to Table 1 above, it was confirmed that the metal complex compounds and the metal nanostructures of the Examples exhibited a polymerization activity in the polymerization reaction for preparing the polypropylene carbonate resin and thus can be suitably used as a catalyst.