IRIDIUM COMPLEX PRODUCTION METHOD

Abstract

A method for manufacturing tris(β-diketonato)iridium by reacting β-diketone with an iridium compound, in which an activation treatment including (a) an alkali treatment and (b) an acid treatment described below is applied to the iridium compound to activate the iridium compound, and to subsequently react the β-diketone, (a) an alkali treatment: a treatment of adding alkali to a solution of the iridium compound to raise pH of the solution to a more alkaline side than that before the alkali addition and to not less than 10, and (b) an acid treatment: a treatment of adding acid to the solution subjected to the alkali treatment to lower pH of the solution to a more acidic side than that before the acid addition and to make the pH difference between solutions before and after the acid addition be not less than 0.1 and not more than 10. The present invention allows manufacture of tris(β-diketonato)iridium utilizing a wide variety of β-diketones.

Claims

1. A method for manufacturing tris(β-diketonato)iridium shown by Chem. 2 in which a β-diketone is coordinated to iridium, by reacting the β-diketone shown by Chem. 1 with an iridium compound, wherein an activation treatment including (a) an alkali treatment and (b) an acid treatment described below is applied to the iridium compound to activate the iridium compound, and to subsequently react the β-diketone, (a) an alkali treatment: a treatment of adding alkali to a solution of the iridium compound to raise pH of the solution to a more alkaline side than that before the alkali addition and to not less than 10, and (b) an acid treatment: a treatment of adding acid to the solution subjected to the alkali treatment to lower pH of the solution to a more acidic side than that before the acid addition and to make the pH difference between solutions before and after the acid addition be not less than 0.1 and not more than 10, ##STR00009## wherein each of R.sup.a and R.sup.b is a hydrocarbon group or substituents in which a hydrogen atom in a hydrocarbon group is substituted by a halogen atom. R.sup.a and R.sup.b may be different substituents, or the identical substituent. R.sup.c is a substituent composed of any of a hydrogen atom, a halogen atom and a hydrocarbon group; and ##STR00010## wherein R.sup.a, R.sup.b, and R.sup.c have the same meaning as in Chem. 1.

2. The method for manufacturing tris(β-diketonato)iridium according to claim 1, wherein pH after alkali addition in the alkali treatment (a) is set to not less than 12.

3. The method for manufacturing tris(β-diketonato)iridium according to claim 1, wherein the pH difference between solutions before and after the alkali addition in the alkali treatment (a) is set to not less than 2 and not more than 13.

4. The method for manufacturing tris(β-diketonato)iridium according to claim 1, wherein the pH difference between solutions before and after the acid addition in the acid treatment (b) is set to not less than 1 and not more than 10.

5. A method for manufacturing a raw material compound for chemical deposition by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 1.

6. A method for manufacturing an intermediate raw material of a phosphorescent material for an organic light-emitting element by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 1.

7. The method for manufacturing tris(β-diketonato)iridium according to claim 2, wherein the pH difference between solutions before and after the alkali addition in the alkali treatment (a) is set to not less than 2 and not more than 13.

8. The method for manufacturing tris(β-diketonato)iridium according to claim 2, wherein the pH difference between solutions before and after the acid addition in the acid treatment (b) is set to not less than 1 and not more than 10.

9. The method for manufacturing tris(β-diketonato)iridium according to claim 3, wherein the pH difference between solutions before and after the acid addition in the acid treatment (b) is set to not less than 1 and not more than 10.

10. A method for manufacturing a raw material compound for chemical deposition by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 2.

11. A method for manufacturing a raw material compound for chemical deposition by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 3.

12. A method for manufacturing a raw material compound for chemical deposition by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 4.

13. A method for manufacturing an intermediate raw material of a phosphorescent material for an organic light-emitting element by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 2.

14. A method for manufacturing an intermediate raw material of a phosphorescent material for an organic light-emitting element by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 3.

15. A method for manufacturing an intermediate raw material of a phosphorescent material for an organic light-emitting element by a method for manufacturing tris(β-diketonato)iridium, the method being defined in claim 4.

Description

MODE FOR CARRYING OUT THE INVENTION

[0044] Hereinafter, suitable embodiments of the present invention will be described. As described above, in the present inventive method for manufacturing tris(β-diketonato)iridium, there are three patterns as timing of the addition of a β-diketone to a solution of an iridium compound, that is, (1) a method of adding a β-diketone to an iridium compound solution for which the activation treatment has completed, (2) a method of adding previously a β-diketone to an iridium compound solution prior to applying each of the alkali treatment and the acid treatment, and (3) a method of adding a β-diketone to an iridium compound solution in the middle of the activation treatment (in an intermediate stage between the alkali treatment and the acid treatment). In the present embodiments, iridium complexes were manufactured based on the (1) to (3) procedures.

First Embodiment

[0045] In the present embodiment, an iridium complex was manufactured according to the procedure (1). Here, iridium(III) nitrate (Ir(NO.sub.3).sub.3) was used as an iridium compound being a starting material, with which 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (another name: hexafluoroacetylacetone) was reacted as a β-diketone, and tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium (tris(hexafluoroacetylacetonato)iridium) was manufactured.

##STR00006##

[0046] There was prepared an iridium nitrate solution in which 18.8 mL of distilled water was added to 20.26 g of iridium nitrate having concentration of 9.1 wt % (iridium content: 1.84 g, 9.6 mmol)). The iridium nitrate solution was a navy aqueous solution and had pH 0.7.

[0047] For the iridium nitrate solution, the alkali treatment and the acid treatment were applied for the activation treatment. In the alkali treatment, a 1 N sodium hydroxide solution was added. In the alkali treatment, pH (0.7) of the iridium nitrate solution before the alkali addition was raised to an alkaline side. In the present embodiment, the alkali addition amount is adjusted so as to give a solution of a different pH value. After the alkali addition, the iridium nitrate solution was left at rest at room temperature for 1 hour.

[0048] Then, 6% diluted nitric acid was added to the solution as the acid treatment. In the acid treatment, too, the acid addition amount is adjusted so as to give a different pH value. Meanwhile, in the above-described alkali treatment and acid treatment, the solution did not show a large change in appearance and was a navy aqueous solution.

[0049] 19.5 g, 59.2 mmol of 1,1,1,6,6,6-hexafluoro-2,4-pentanedione was added to the iridium nitrate solution for which the alkali treatment and the acid treatment were applied to complete the activation treatment. The addition amount corresponds to 6 equivalents relative to 1 mol of iridium. After the addition of 1,1,1,6,6,6-hexafluoro-2,4-pentanedione, the solution was heated to 55° C. and held for 2.5 hours for a reaction.

[0050] The reaction liquid after the reaction became a dark yellow suspension. pH of the reaction liquid was slightly lowered to an acidic side. The reaction liquid was filtrated and subjected to solid-liquid separation, and the solid content was washed and then was purified with a column (solvent; hexane:ethyl acetate=5:1) and tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium was collected.

[0051] The synthesized and collected iridium complex was analyzed by 1H NMR (proton nuclear magnetic resonance) and X-ray structural analysis. Here, 1H NMR was confirmed by 1H NMR apparatus (400 MHz) analysis using CDCl.sub.3 as a measurement solvent. In addition, a method of X-ray structural analysis used a single crystal X-ray structural analysis apparatus (VariMax with RAPID) for analysis. The X-ray structural analysis was used together with 1H NMR, because 1H NMR alone is insufficient for the analysis of tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium in which 1,1,1,6,6,6-hexafluoro-2,4-pentanedione being a symmetric β-diketone is coordinated. Then, as the result of these analyses, it was confirmed that the iridium complex manufactured this time was surely tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium. Together with the confirmation, yield was calculated for the collected iridium complex (calculated from iridium quantity).

[0052] The present embodiment tried a synthesis of an iridium complex based on a conventional method of not applying the alkali treatment and the acid treatment, in addition to a test example of applying the alkali treatment and the acid treatment. Further, a case was also investigated where the alkali treatment alone was applied without application of the acid treatment.

[0053] The present embodiment measures pH of the iridium compound solution at each step of the alkali treatment, the acid treatment, and the addition of a β-diketone. The pH measuring method performed measurement after immersing a pH composite electrode (directly reads the potential difference between a glass electrode and a comparative electrode each integrated with a temperature sensor) in three standard solutions of pH 6.86, pH 4.01 and pH 9.18, and carrying out three-point calibration.

[0054] In relation to results of synthesis tests of tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium in the present embodiment, there are listed pH values after the alkali treatment, the acid treatment and the addition of the β-diketone, and yields in Table 1.

TABLE-US-00001 TABLE 1 Alkali Acid Ir compound treatment treatment β-diketone Kind pH Kind pH Kind pH Kind pH Yield Example 1 Ir(NO.sub.3).sub.3 0.7 NaOH 10 HNO.sub.3 6 hfp 5  8% Example 2 11 6 5 10% Example 3 12 6 5 16% Example 4 13 12 11 29% Example 5 13 10 9 30% Example 6 13 8 7 29% Example 7 13 6 5 25% Example 8 13 3 3 14% Comparative 13 1 1  0% example 1 Comparative 9 6 5  0% example 2 Comparative 7 6 5  0% example 3 Comparative — 0.7 — 0.7 0.7  0% example 4 Comparative NaOH 5 — 5 3  0% example 5 hfp: 1,1,1,6,6,6-hexafluoro-2,4-pentanedione

[0055] From Table 1, it is known that tris(1,1,1,6,6,6-hexafluoro-2,4-pentanedionato)iridium can be synthesized by the activation treatment in which the alkali treatment and the acid treatment are combined (Examples 1 to 8). In the activation treatment, it is known that appropriate pH in treatment exists in each of the alkali treatment and the acid treatment. That is, in the alkali treatment, it is required to set pH to not less than 10 while raising pH to an alkaline side by the alkali addition and, in addition, and, in Comparative Examples 2 and 3 that do not include the requirement, the synthesis of the iridium complex was not confirmed. Further, in the acid treatment, too, it is required not to simply shift the solution to an acidic side but to set the pH difference to not less than 0.1 and not more than 10, and, in Comparative Example 1 that does not include the requirement, the synthesis of the iridium complex was not confirmed. Further, the synthesis of the iridium complex was not confirmed in Comparative Example 4 that does not apply the alkali treatment and the acid treatment, and in Comparative Example 5 that applies the alkali treatment alone. Meanwhile, in these test examples in which the synthesis of the iridium complex was not confirmed, no change was observed in the solution, and, further, the targeted material was not observed when the solution was analyzed by thin-layer chromatography (TLC).

Second Embodiment

[0056] In the present embodiment, an iridium complex was manufactured according to the procedure of (2). As an iridium compound being a starting material, iridium (III) chloride (IrCl.sub.3.nH.sub.2O) was used, with which 1,1,1-trifluoro-2,4-hexanedione as a β-diketone was reacted to thereby manufacture tris(1,1,1-trifluoro-2,4-hexanedionato)iridium.

##STR00007##

[0057] The present embodiment is a method of adding previously a β-diketone to an iridium compound solution and then applying the activation treatment. First, there was prepared an iridium chloride solution obtained by adding 94 mL of distilled water to 10.0 g of iridium chloride (iridium content of 5.2 g). Further, 25.9 g, 168.1 mmol of 1,1,1-trifluoro-2,4-hexanedione was added to the solution. The addition amount corresponds to 6 equivalents relative to 1 mol of iridium. No change in the appearance of the solution was observed when 1,1,1-trifluoro-2,4-hexanedione was added to the iridium chloride solution, and it was confirmed that no reaction was generated.

[0058] Then, the alkali treatment and the acid treatment were applied to the mixed solution. In the present embodiment, a 1 N sodium carbonate solution was used in the alkali treatment. In the acid treatment, 6% acetic acid was used. The method of the activation treatment is basically the same as in the first embodiment.

[0059] After application of the alkali treatment and the acid treatment, the mixed solution was heated to 55° C. and held for 2.5 hours for a reaction. The solution after the reaction became a dark yellow suspension. The reaction liquid was filtrated and subjected to solid-liquid separation, and the solid content was washed and then purified with a column, and tris(1,1,1-trifluoro-2,4-hexanedionato)iridium was collected. The synthesized iridium complex was analyzed by .sup.1H NMR, and it was confirmed that the iridium complex was surely tris(1,1,1-trifluoro-2,4-hexanedionato)iridium. Further, the yield of the iridium complex was calculated.

[0060] In the present embodiment, too, a method of not applying the alkali treatment and the acid treatment was investigated, and a case of applying the acid treatment alone was investigated. In relation to results of synthesis tests of tris(1,1,1-trifluoro-2,4-hexanedionato)iridium in the present embodiment, there are listed pH values after the alkali treatment, the acid treatment and the addition of the β-diketone, together with yields in Table 2. Meanwhile, each of the pH measuring method and the method of .sup.1H NMR at each step in the present embodiment was the same as in the first embodiment.

TABLE-US-00002 TABLE 2 Ir Alkali compound β-diketone treatment Acid treatment Kind pH Kind pH Kind pH Kind pH Yield Example 9 IrCl.sub.3 2 tfh 2 Na.sub.2CO.sub.3 10 CH.sub.3COOH 6 3% Example 10 2 11 6 5% Example 11 2 12 6 8% Example 12 2 13 12 14%  Example 13 2 13 10 16%  Example 14 2 13 8 14%  Example 15 2 13 5 12%  Example 16 2 13 3 3% Comparative 2 13 1 0% example 6 Comparative 2 9 6 0% example 7 Comparative 2 7 5 0% example 8 Comparative 2 — 2 — 2 0% example 9 Comparative 2 — 2 CH.sub.3COOH 1 0% example 10 tfh: 1,1,1-trifluoro-2,4-hexanedione

[0061] It can be confirmed that the iridium complex can be synthesized by the activation treatment even when β-diketones are added to an iridium compound solution before a reaction (Examples 9 to 16). Further, it is known that the necessity of the alkali treatment and the acid treatment and a suitable pH range and pH difference in each treatment have the same tendency as in the first embodiment. Meanwhile, in the present embodiment, a method of applying the acid treatment alone was also tried, but a complex was not synthesized (Comparative Example 10).

Third Embodiment

[0062] In the present embodiment, in the present embodiment, an iridium complex was manufactured according to the procedure of (3). Ammonium hexachloroiridate (III) ((NH.sub.4).sub.3[IrCl.sub.6]) was used as an iridium compound being a starting material, with which 1,1,1-trifluoro-2,4-pentanedione (1,1,1-trifluoroacetylacetone) was reacted as a β-diketone, to thereby manufacture tris(1,1,1-trifluoro-2,4-pentanedionato)iridium (tris(1,1,1-trifluoroacetylacetonato)iridium).

##STR00008##

[0063] The embodiment, after applying the alkali treatment to an ammonium hexachloroiridate solution, adds 1,1,1-trifluoro-2,4-pentanedione thereto, and thereafter applies the acid treatment.

[0064] First, there was prepared an ammonium hexachloroiridate solution in which 470 mL of distilled water was added to 10.05 g of ammonium hexachloroiridate (iridium content of 4.06 g, 21.1 mmol). Then, the ammonium hexachloroiridate solution was subjected to the alkali treatment. The alkali treatment added a 1 N potassium hydroxide solution. After the alkali addition, the ammonium hexachloroiridate solution was left at rest for 1 hour.

[0065] 25.9 g, 168.1 mmol of 1,1,1-trifluoro-2,4-pentanedione was added to the ammonium hexachloroiridate solution subjected to the alkali treatment. The addition amount corresponds to 6 equivalents relative to 1 mol of iridium.

[0066] Then, the acid treatment was applied to the solution. The acid treatment used 6% phosphoric acid. In the pH adjustment by the acid treatment, a mixed solution of the ammonium hexachloroiridate solution and 1,1,1-trifluoro-2,4-pentanedionato was used as a solution before the adjustment, and pH was adjusted to an acidic side value with reference to the pH of the solution before the adjustment. After the acid treatment, the solution was heated to 55° C. and held for 2.5 hours for a reaction.

[0067] The reaction liquid after the reaction became a dark yellow suspension. The reaction liquid was filtrated and subjected to solid-liquid separation, and the solid content was washed and then purified with a column (solvent; hexane: ethyl acetate=5:1) and tris(1,1,1-trifluoro-2,4-pentanedionato)iridium was collected. The synthesized iridium complex was analyzed by .sup.1H NMR, and it was confirmed that the iridium complex was surely tris(1,1,1-trifluoro-2,4-pentanedionato)iridium. Further, the yield was calculated.

[0068] In the present embodiment, too, there were investigated a method of not applying the alkali treatment and the acid treatment, and a case of applying the acid treatment alone. In relation to results of synthesis tests of tris(1,1,1-trifluoro-2,4-pentanedionato)iridium in the present embodiment, there are listed pH values after the alkali treatment, the acid treatment and the addition of the β-diketone, together with yields in Table 3. Meanwhile, each of the pH measuring method and the method of .sup.1H NMR at each step in the present embodiment was the same as in the first embodiment.

TABLE-US-00003 TABLE 3 Alkali Acid Ir compound treatment β-diketone treatment Kind pH Kind pH Kind pH Kind pH Yield Example 17 (NH.sub.4).sub.3IrCl.sub.6 5 KOH 10 tfp 9 H.sub.3PO.sub.4 6 4% Example 18 11 10 6 7% Example 19 12 11 6 14%  Example 20 13 12 11 23%  Example 21 13 12 10 25%  Example 22 13 12 8 24%  Example 23 13 12 5 11%  Example 24 13 12 3 4% Comparative 13 12 1 0% example 11 Comparative 9 8 6 0% example 12 Comparative 7 6 5 0% example 13 Comparative — 5 5 — 5 0% example 14 Comparative — 5 5 H.sub.3PO.sub.4 3 0% example 15 tfp: 1,1,1-trifluoro-2,4-pentanedione

[0069] It can be confirmed that it is possible to synthesize the iridium complex by applying the acid treatment to accomplish the activation treatment, even when the β-diketone was added between the alkali treatment and the acid treatment, that is, in the middle of the activation treatment (Examples 17 to 24). In the method, too, It was confirmed that whether or not the complex could be synthesized was determined by the pH range or pH difference in the alkali treatment or the acid treatment.

INDUSTRIAL APPLICABILITY

[0070] As described above, the present invention allows a wide variety of β-diketones to be coordinated to iridium. The present inventive method is useful as a method for manufacturing raw material compounds for chemical deposition such as a CVD method and an ALD method, and, in addition, is also useful as a method for manufacturing raw materials (intermediate raw materials) of phosphorescent materials for organic light-emitting elements such as an organic EL element and organic ECL element. The present invention is useful as means for broadening the possibility of manufacturing tris(β-diketonato)iridium in various applications.