KR101158768B1 - Eu(ii)/organophosphorous complexes, a method for preparation of eu(ii)/organophosphorous complexes and application to blue emitting devices - Google Patents

Abstract

PURPOSE: A bivalent europium complex and a blue emitting device using the same are provided to ensure high solubility in organic solvent and to easily form a thin film. CONSTITUTION: A bivalent europium transition metal complex is denoted by chemical formula 1 or 2. A method for preparing the complex comprises: a step of preparing europium halide salt with 2 oxidation number; and a step of directly refluxing the europium halide salt and organophosphate in oxygen-free organic solvent to prepare Eu(II)/organophosphorous complexes; a step of purifying the complexes.

Description

Eu (II) / Organophosphorous Complexes, a method for preparation of Eu (II) / Organophosphorous Complexes and application to Blue Emitting Devices}

The present invention relates to a complex in which an organophosphate ligand is coordinated to europium (II) having a divalent oxidation state (hereinafter referred to as 'Eu (II) / organophosphate complex'), a method for preparing the same, and a phosphor comprising the complex And its blue light emitting device.

More specifically, Eu (II) / organic phosphate complex, which is excited by UV light source and is excellent in luminescence brightness and suitable for blue light emitting device, a method for preparing the same, and applying the same as a phosphor to prepare a thin film, TECHNICAL FIELD The present invention relates to applications for UV light conversion molecular devices, including electroluminescence (EL) devices.

The organic electroluminescent device is a device that emits light in the process of injecting and recombining electrons and holes by electric fields applied to both sides of the organic material layer. Most of the light emitting materials used to date are organic compounds. In order to be used as a full-color display in the future, red, green and blue emitters must emit narrow luminescence and a short decaytime of a few μs-ms. Lanthanide ions cause luminescence to meet these requirements. To date, development of Eu (III) complexes, which are + trivalent cations as red phosphors, and Tb (III) complexes, which are used as green phosphors, has been widely developed. The optical properties of the + 3-valent lanthanides correspond to the 4f → 4f transition. This transition is prohibited for the electric dipole but has some limitations for its application as an electroluminescent phosphor because it is partially tolerated by the crystal field conditions of the complex. In contrast, the optical properties of the divalent cation Eu (II) ion are determined by the 4f → 5d transition, which causes very strong luminescence because it is allowed by the electric dipole moment. However, the application of Eu (II) to phosphors is limited to oxides or sulfides present as dopants in the phosphor lattice. This is because the oxidation state of + 2-valent is very unstable and easily oxidized to + trivalent in an oxidizing atmosphere. For this reason, there is no development of Eu (II) complexes and techniques for applying them as phosphors.

In general, Eu (II) ions absorb light energy or electrical energy to cause an electron transition from 4f → 5d to have an excited electron configuration of 4f ⁶ 5d. Transition from the excited state to the ground state emits strong luminescence, and the wavelength of the emitted luminescence is determined by the ligand field being coordinated.

In general, +2 valence Eu (II) ions are easily oxidized to +3 valence of red due to polar molecules containing oxygen and sulfur atoms present in solvent molecules when exposed to air or complexed. Therefore, in order to obtain a + divalent Eu (II) compound, synthesis should be performed in an anhydride organic solvent containing no oxygen or sulfur atoms, and the reactivity of the ligand forming the complex should be relatively low. In addition, in order to make the synthesized Eu (II) complex into an EL device, it must be chemically stable in anhydrous organic solvent and have good solubility. Furthermore, it should be useful for thin film production by forming a uniform brand with the polymer.

The present invention is stable in the oxidation atmosphere, provides a + divalent Eu (II) / organic phosphoric acid complex having a good solubility in organic solvents and a method for producing the same, and can be excited by UV light or electric field by branding it with a polymer The present invention aims to provide a blue phosphor of Eu (II) having high brightness.

In order to achieve the above object, the present invention provides a divalent europium rare earth metal complex represented by the following formula (1) or (2).

<Formula 1>

<Formula 2>

In Formula 1 or Formula 2, R ^I to R ^IV bonded to a phosphorus atom may each be the same or different, any one alkyl group selected from 1 to 20 carbon atoms; Any one aryl group selected from 6 to 20 carbon atoms; Any one alkoxy group selected from 1 to 20 carbon atoms; Phenoxy group having any one alkyl substituent group selected from 1 to 10 carbon atoms; It is any functional group selected from

In the complex of Formula 2, each organophosphorous ligand that binds to europium is of a different kind.

In another aspect, the present invention provides the following three types of preparation method for producing a complex of formula (I) or formula (2).

1) Method for preparing a complex by one step reaction between europium (II) halide and organophosphate

2) Dehydrotonation of organophosphoric acid with a strong base to convert the organophosphoric acid into an alkali metal salt, followed by reaction with europium (II) halide to prepare a complex by a two-step reaction

3) A two-step manufacturing method for preparing a complex of divalent europium (II) solution by reacting trivalent europium oxide (Eu ₂ O ₃ ) with concentrated hydrochloric acid and then reacting it with organic phosphoric acid to prepare a complex.

In another aspect, the present invention is to provide a phosphor comprising a complex of Formula 1 or Formula 2.

In addition, the present invention has another object to provide a blue EL device by blending the complex of Formula 1 or Formula 2 with a polymer to thin.

According to the present invention, by selecting an organophosphate-based ligand system, synthesizing a + divalent Eu (II) complex in anhydrous nonpolar solvent, and branding with a polymer, high brightness Eu (which can be excited by photons or electrical energy in the UV region) A blue phosphor of II) can be provided. In addition, the blue phosphor can be used to manufacture blue light emitting diodes and electroluminescent diodes that are excited with light in the UV region and emit blue light, and can be used together with green and red phosphors to be applied to a variety of white light emitting diodes. Can be.

The Eu (II) / organophosphate complex absorbs UV light in the 300-420 nm region and emits strong blue fluorescence corresponding to the 350-550 nm region. In addition, since the Eu (II) complex has good solubility in organic solvents, a thin film is easily formed by a spin coating method or a wet method. Furthermore, Eu (II) complexes represented by Formulas 1 and 2 form uniform branding with polymers such as polystyrene (Pst), PMMA, PEG and the like. Such a brand with polymers provides a very useful advantage for thin film fabrication which is very useful for fabricating optical fiber amplifiers and organic light emitting devices.

1 is a luminescence spectrum (λ _exc = 325 nm) of [Eu (BEHP) ₂ ] complex prepared according to Example 1. FIG.
2 is a luminescence spectrum (λ _ems = 440 nm) of the [Eu (BEHP) ₂ ] complex prepared according to Example 2. FIG.
3 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (BEHP) ₂ ] complex prepared according to Example 3. FIG.
4 is an excited spectrum of the [Eu (BEHP) ₂ ] complex prepared in Example 3 (λ _ems = 450 nm).
5 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (PC88A) ₂ ] complex prepared according to Example 4. FIG.
6 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (PC88A) ₂ ] complex prepared according to Example 5. FIG.
7 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (PC88A) ₂ ] complex prepared according to Example 6. FIG.
8 is an excited spectrum of the [Eu (PC88A) ₂ ] complex prepared according to Example 6 (λ _ems = 450 nm).
9 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (BEHP) (DPP)] complex prepared according to Example 8. FIG.
FIG. 10 is an excited spectrum (λ _ems = 422 nm) of the [Eu (BEHP) (DPP)] complex prepared according to Example 8. FIG.
11 is a luminescence spectrum (λ _exc = 325 nm) of the [Eu (PC88A) (DPP)] complex prepared according to Example 9. FIG.
12 is an excited spectrum of the [Eu (PC88A) (DPP)] complex prepared according to Example 9 (λ _ems = 422 nm)>
FIG. 13 is an FE-SEM image of side surfaces of a brand thin film prepared on a quartz slide substrate according to Example 15.
14 is an image of a solution (left) and a thin film (right) of the [Eu (BEHP) ₂ ] / polymer brand according to the present invention taken while irradiating a UV lamp of 365 nm.
Figure 15 is the luminescence spectrum (λ _exc = 325 nm) of [Eu (BEHP) ₂ ] / polymer brand thin films according to the invention.
16 is the luminescence spectrum (λ _exc = 325 nm) of [Eu (PC88A) ₂ ] / polymer brand thin film according to the present invention.

The present invention is characterized by providing a europium (II) complex represented by the following formula (1) or (2).

<Formula 1>

<Formula 2>

In Formula 1 or Formula 2, R ^I to R ^IV bonded to the phosphorus atom may be the same or different, each alkyl group selected from 1 to 20 carbon atoms; Any one aryl group selected from 6 to 20 carbon atoms; Any one alkoxy group selected from 1 to 20 carbon atoms; Phenoxy group having any one alkyl substituent group selected from 1 to 10 carbon atoms; It is any functional group selected from

In the complex of Formula 2, each of the organophosphoric acid ligands binding to europium is of a different kind.

In the complex of Formula 1 or Formula 2, the organophosphate ligand that binds to europium is preferably any one alkoxy group wherein a substituent bonded to the phosphorus atom is selected from 1 to 20 carbon atoms, or 6 carbon atoms. Any aryl group selected from -20 may be.

In this case, the ligand bound to the europium may be an organophosphate ligand consisting of two alkoxy groups, one hydroxy OH and one oxygen atom, and also two alkyl groups, one hydroxy OH and one oxygen It can be an organophosphate ligand composed of atoms. In this case, each ligand has a negatively-charged resonant structure between two oxygen end groups as H ions dissociate when bound to Eu (II) ions.

In addition, the ligand which binds to the europium is any one alkoxy selected from the group having 1 to 20 carbon atoms substituted with a phosphorus atom; The other may be formed of any one alkyl group selected from 1-20 carbon atoms, or one aryl group selected from 6-20 carbon atoms.

In this case, the ligand bound to the europium may be an organophosphate ligand composed of one alkoxy group, one alkyl group, one hydroxy OH and one oxygen atom, and also one alkoxy group, one aryl group. It can be an organophosphate ligand composed of one hydroxy OH and one oxygen atom. It may also be an organophosphate ligand composed of one aryl group, one alkyl group, one hydroxy OH and one oxygen atom. In this case as well, each ligand dissociates H ions when bound to Eu (II) ions, resulting in a negatively charged resonance structure between the two oxygen end groups.

Ligand binding to the europium is more preferably selected from bis (2-ethylhexyl) phosphoric acid, 2-ethylhexyl phosphonic acid monomer-2-ethylhexyl ester (PC88A-H), or diphenylphosphoric acid (DPP-H) It may be any one of these, and also when the H ions are dissociated when combined with Eu (II) ions, the OH portion of each ligand is combined with Eu (II) ions as a dehydrogenated form.

The present invention also provides the following three kinds of preparation methods for producing the complex of Formula I or Formula 2.

(1) Method for preparing a complex by one step reaction between Eu (II) -halide salt and organophosphate

The first manufacturing method may be performed as the following steps.

1) preparing a europium halide salt having a divalent oxidation number; 2) reacting the europium halide with organophosphoric acid directly in an organic solvent containing no oxygen atom to reflux to produce hydrogen chloride as a side reaction product; 3) Purifying the resulting Eu (II) / organophosphate complex.

The europium halide as, the type of the functional group bonded to the personnel chair as EuCl _2, EuBr _2, EuI ₂ and are available to any salt, kind of the organic acid used is selected from FIG. Salpin above, having 1 to 20 carbon atoms Any one alkyl group selected from; Any one aryl group selected from 6 to 20 carbon atoms; Any one alkoxy group selected from 1 to 20 carbon atoms; Phenoxy group having any one alkyl substituent group selected from 1 to 10 carbon atoms; Any functional group selected from among can be used.

For example, EuCl ₂ may be used as the europium halide and BEHP-H (bis (2-ethylhexyl) phosphoric acid) may be used as the organic phosphoric acid.

The solvent to be used may be an organic solvent containing no oxygen or sulfur, and preferably, hydrogen, aromatic hydrocarbons and the like are suitable, and the reaction is preferably performed under reflux conditions in order to increase the reaction rate.

(2) Dehydrotonation of organophosphoric acid with a strong base to convert the organophosphoric acid into an alkali metal salt, followed by a two-step reaction in which europium 2 reacts with a halide.

The second manufacturing method may be performed as the following steps.

1) preparing a europium halide salt having a divalent oxidation number; 2) converting the organophosphoric acid to an alkali metal salt of organophosphoric acid by deprotonation with a base; 3) reacting the alkali metal salt of the organophosphoric acid obtained in step 2 with the europium halide salt in the first step to produce an alkali metal-halide salt as a side reaction; 4) Purifying the resulting Eu (II) / organophosphate complex.

Method europium Likewise passage halide of the second is possible using any of the salt is selected from the EuCl _2, EuBr _2, EuI _2, as the type of the organic acid also salpin previously used, the functional group bonded to the person sleeping As a kind, Any alkyl group chosen from C1-C20; Any one aryl group selected from 6 to 20 carbon atoms; Any one alkoxy group selected from 1 to 20 carbon atoms; Phenoxy group having any one alkyl substituent group selected from 1 to 10 carbon atoms; Any functional group selected from among can be used.

Bases that can be used in the step of dehydrotonating organophosphates with alkali metal salts of organophosphates are suitable for bases with low nucleophilicity that do not cause other side reactions with organophosphate ligands. Preferably, it has a strong base such as KH, NaH and the like.

For example, EuCl ₂ may be used as the europium halide, NaH may be used as a strong base, and BEHP-H (bis (2-ethylhexyl) phosphoric acid) may be used as the organic phosphoric acid.

The solvent used may be an organic solvent which does not contain oxygen or sulfur, and preferably hydrogen, aromatic hydrocarbons and the like are suitable. It is preferable to react under reflux conditions in order to increase the reaction rate.

(3) preparing a divalent europium solution by reacting trivalent europium oxide (Eu ₂ O ₃ ) with concentrated hydrochloric acid, and then reacting it with organic phosphoric acid to prepare a complex.

The third manufacturing method may be performed as the following steps.

1) preparing a europium oxide (Eu ₂ O ₃ ) having a trivalent oxidation number; 2) reacting the europium oxide (Eu ₂ O ₃ ) with concentrated hydrochloric acid (conc. HCl) to obtain an aqueous solution containing europium ions having a divalent oxidation state; 3) reacting an aqueous solution containing europium ions having a divalent oxidation state obtained in step 2 with organic phosphoric acid by refluxing directly in an organic solvent containing no oxygen atom to generate hydrogen as a side reaction product; 4) Purifying the resulting Eu (II) / organophosphate complex

The kind of organophosphoric acid used in the third manufacturing method as well is a kind of functional group bonded to a person, as in the salpin bar, any one alkyl group selected from 1 to 20 carbon atoms; Any one aryl group selected from 6 to 20 carbon atoms; Any one alkoxy group selected from 1 to 20 carbon atoms; Phenoxy group having any one alkyl substituent group selected from 1 to 10 carbon atoms; Any functional group selected from among can be used.

In the step of obtaining the aqueous solution containing europium ions having a divalent oxidation state by reacting the europium oxide (Eu ₂ O ₃ ) with hydrochloric acid, it is advantageous to use concentrated hydrochloric acid (conc. HCl). As a solvent used, alcohol, such as methanol, is preferable, and it is advantageous for subsequent reaction to reduce the amount of solvent. It is preferable to react under reflux conditions in order to increase the reaction rate.

For example, after the reaction of europium oxide with concentrated hydrochloric acid, BEHP-H (bis (2-ethylhexyl) phosphoric acid) may be used as the organic phosphoric acid.

The solvent used in the reaction between the europium divalent aqueous solution and the organic phosphoric acid may be an organic solvent containing no oxygen or sulfur, and preferably hydrogen, aromatic hydrocarbons, and the like. It is also preferable to react under reflux conditions in order to increase the reaction rate.

The present invention also provides a phosphor comprising the Eu (II) / organic phosphate complex of Formula 1 or Formula 2 above. The blue phosphor of the present invention absorbs UV light in the 300-420 nm region and emits strong blue luminescence in the 350-550 nm region. Therefore, the present invention can be used for UV converting molecular devices including blue EL devices. In addition, since it can be excited with a known green phosphor and a red phosphor to emit white, it can be used in the manufacture of a white light emitting device.

In another aspect, the present invention provides a phosphor composition obtained by branding a phosphor and a polymer comprising the Eu (II) / organic phosphoric acid complex of the formula (1) or (2).

In another aspect, the present invention provides a method for producing a thin film and a thin film prepared by branding a phosphor and a polymer comprising the Eu (II) / organic phosphoric acid complex of Formula 1 or Formula 2 and dissolved in an organic solvent This provides another feature of providing applicability to a blue EL device.

The type of polymer that can be used for blending with the phosphor is preferably one selected from polystyrene, PVA, PMMA, and PEG, but is not limited thereto. Generally, any polymer that can be used as a phosphor in the art is used. It is possible.

For example, blending with a polymer in the present invention, Eu (II) complexes form a mixture of polystyrene (Pst) and a uniform phase. Brands mixed with Eu (II) complexes and polymers by weight of about 50: 50% increase the luminescence intensity of Eu (II) complexes and are very useful for producing highly uniform thin films.

Hereinafter, the present invention will be described in more detail with reference to the following examples and drawings, but the present invention is not limited thereto.

Example 1: [Eu (BEHP) according to the present invention ₂ ] Preparation of Phosphors1

Phosphor was synthesized by directly reacting with organophosphoric acid according to the following scheme.

EuCl ₂ (99.99%, Aldrich Co.) and BEHP-H (97%, C ₁₆ H ₃₅ O ₄ P, Bis (2-ethylhexyl) phosphate, Aldrich Co.) were used without purification. Add BEHP-H 2mmol (0.644g) to 150 mL of anhydrous C ₆ H ₁₂ (99.5%), reflux at 30 ℃ ~ 40 ℃, stir with a magnet rod for 3 hours, and add 1 mmol (0.223g) of EuCl _2. The mixture was kept at 30 ° C. to 40 ° C. and stirred with a magnetic rod for about 3 days (72 hours) until all the crystals of EuCl ₂ were dissolved in reflux. After the reaction solution was filtered using a b㎻chner funnel, the material on the filter paper was discarded and the solution was evaporated under vacuum. 150 mL of C ₆ H ₁₂ was added to this material to dissolve it, and the solvent was obtained by evaporation at room temperature. The material thus obtained was slightly gelled and emitted blue strong fluorescence when viewed in a fluorescent lamp at 365 nm. After drying in an electric oven it was stored in the air.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (BEHP) ₂ ]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 19.2%, C 48.3%, H 8.6%, P 7.8%.

Experimental values: Eu 19.0%, C 48.2%, H 9.7%, P 7.9%.

In the synthesized [Eu (BEHP) ₂ ] phosphor, BEHP, which has a resonant ion structure of charge, acts as a coordination ligand to satisfy stable 4-coordination bonds with Eu (III) ions.

Example 2: [Eu (BEHP) according to the present invention ₂ ] Preparation of Phosphor 2

Phosphor was synthesized through an alkali alkali phosphate according to the following scheme.

BEHP-H 2 mmol (0.644 g) and NaH 2 mmol (0.048 g) were added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%), and refluxed at 30 ° C. to 40 ° C. until no more H ₂ was generated. . 1 mmol (0.223 g) of EuCl ₂ was added thereto, and the mixture was kept at 30 ° C. to 40 ° C. while stirring with a magnetic rod for about 3 days (72 hours) until all the crystals of EuCl ₂ were dissolved in reflux state as in Example 1 Synthesized.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (BEHP) ₂ ]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 19.2%, C 48.3%, H 8.6%, P 7.8%.

Experimental Value: Eu 18.4%, C 46.7%, H 9.5%, P 7.5%.

The same result as in Example 1 was obtained.

Example 3: [Eu (BEHP) according to the present invention ₂ ] Preparation of Phosphors 3

[Eu (BEHP)] ₂ complex was synthesized from Eu ₂ O ₃ by the following scheme.

0.25 g (0.71 mmol) of Eu 2 O 3 (99.99%) was dissolved in 0.741 mL of a concentrated HCl solution added with a small amount of methanol. The solution was added to 100 mL of anhydrous C6H12 (99.5%) in which 2.8 mmol (0.9016 g) of BEHP-H was dissolved, and then refluxed at 30 ° C. to 40 ° C. until no more H 2 was generated. Sufficient dry MgSO4 was added to the mixture, followed by stirring for 30 minutes with a magnetic rod. After removing the powder MgSO4 using a centrifuge the solvent C6H12 was evaporated and dried in an electric oven at 80 ° C.

Thus, the molecular formula of the composite complex was confirmed by elemental analysis that the C ₆ H 4 molecules of ₁₂ the _{[Eu (BEHP) 2]?} 4C 6 H 12 solvation. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 13.4%, C 59.5%, H 10.3%, P 5.5%.

Experimental values: Eu 13.3%, C 58.7%, H 10.5%, P 5.6%.

Example 4: [Eu (PC-88A) according to the present invention ₂ ] Preparation of Phosphors1

Phosphor was synthesized by directly reacting with organophosphoric acid according to the following scheme.

EuCl ₂ (99.99%) and PC88-H (98%, C ₁₆ H ₃₅ O ₃ P.) were used without purification. 2 mmol (0.612 g) of PC88 was added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%, anhydrous), reflux at 30 ° C. to 40 ° C., stirred with a magnet rod for 3 hours, and 1 mmol (0.223 g) of EuCl ₂ was added. Then, the mixture was kept at 30 ° C. to 40 ° C. and stirred with a magnet rod for about 3 days (72 hours) until all the crystals of EuCl ₂ were dissolved in reflux. After the reaction solution was filtered using a b㎻chner funnel, the material on the filter paper was discarded, and the solvent was evaporated in vacuo. 150 mL of anhydrous C ₆ H ₁₂ was added to this material to dissolve it, and the solvent was obtained by evaporation at room temperature. The material thus obtained was slightly gelled and emitted blue strong fluorescence when viewed in a fluorescent lamp at 365 nm.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (PC88A) ₂ ]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theoretic: Eu 19.9%, C 50.3%, H 8.9%, P 8.1%.

Experimental Value: Eu 17.3%, C 46.5%, H 9.5%, P 7.2%.

In the synthesized [Eu (PC88A) ₂ ] phosphor, PC88A having a resonant ion structure of charge satisfies stable 4-coordinate bond with Eu (III) ion by acting as a coordination ligand. The molecular formula is as follows.

Example 5: [Eu (PC88A) according to the invention ₂ ] Preparation of Phosphor 2

Phosphor was synthesized through an alkali alkali phosphate according to the following scheme.

2 mmol (0.612 g) of PC88-H and 2 mmol (0.048 g) of NaH were added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%), and refluxed at 30 ° C. to 40 ° C. until no more H ₂ was generated. . 1 mmol (0.223 g) of EuCl ₂ was added thereto, and the mixture was kept at 30 ° C. to 40 ° C. while stirring with a magnetic rod for about 3 days (72 hours) until all the crystals of EuCl ₂ were dissolved in reflux state as in Example 3 Synthesized.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (PC88A) ₂ ]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theoretic: Eu 19.9%, C 50.3%, H 8.9%, P 8.1%.

Experimental Value: Eu 16.5%, C 45.7%, H 9.1%, P 6.7%.

Example 6: [Eu (PC88A) according to the invention) ₂ ] Preparation of Phosphors 3

[Eu (PC88A)] ₂ complex was synthesized from Eu ₂ O ₃ by the following scheme.

0.25 g (0.71 mmol) of Eu ₂ O ₃ (99.99%) were dissolved in 0.741 mL of a concentrated HCl solution added with a small amount of methanol. This solution was added to 100 mL of anhydrous C6H12 (99.5%) in which 2.8 mmol (0.905 g) of PC88A-H was dissolved, and then refluxed at 30 ° C. to 40 ° C. until no more H ₂ was generated. Sufficient dry MgSO ₄ was added to the mixture, followed by stirring for 30 minutes with a magnetic rod. After removing the powder MgSO ₄ using a centrifuge, the solvent C ₆ H ₁₂ was evaporated and dried in an 80 ° C. electric oven.

Thus, the molecular formula of the composite complex was confirmed by elemental analysis that the C ₆ H 4 molecules of ₁₂ the _{[Eu (PC88A) 2]?} 4C 6 H 12 solvation. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 13.8%, C 61.2%, H 10.6%, P 5.6%.

Experimental Value: Eu 12.0%, C 61.4%, H 11.0%, P 5.0%.

Example 7: Preparation of [Eu (BEHP) (DPP)] phosphor according to the present invention 1

A phosphor was synthesized according to the following scheme.

EuCl ₂ (99.99%, Aldrich Co.), BEHP-H (97%, C ₁₆ H ₃₅ O ₄ P, Bis (2-ethylhexyl) phosphate, Aldrich Co.) and DPP-H (99%, diphenylphosphic acid, Aldrich Co) was used without purification. 1 mmol (0.322 g) of BEHP-H and 1 mmlo (0.191 g) of DPP-H are added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%), and refluxed at 30 ° C. to 40 ° C. for 3 hours, followed by EuCl ₂ 1 mmol (0.223 g) was added thereto, and the mixture was kept at 30 ° C. to 40 ° C. and stirred with a magnetic rod for about 3 days (72 hours) until all the crystals of EuCl ₂ were dissolved in reflux. After the reaction solution was filtered using a b㎻chner funnel, the material on the filter paper was discarded and the solution was placed in a vacuum pump to evaporate the solvent. 150 mL of C ₆ H ₁₂ was added to this material to dissolve it, and the solvent was obtained by evaporation at room temperature. The material thus obtained was a soft powdery material that emitted blue strong fluorescence when viewed in a fluorescent lamp at 365 nm. After drying in an electric oven it was stored in the air.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (BEHP) (DPP)]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 22.0%, P 9.3%.

Experimental Value: Eu 21.5%, P 9,6%.

In the synthesized [Eu (BEHP) (DPP)] phosphors, BEHP and DPP, each having a resonant structure of charge, act as a four coordinating ligand, and Eu (II) ions satisfy the most stable 1: 2 ion bond. Is as follows.

Example 8: Preparation of [Eu (BEHP) (DPP)] phosphor according to the present invention 2

Phosphor was synthesized through an alkali alkali phosphate according to the following scheme.

1 mmol BEHPH (0.322 g), DPP-H 1 mmlo (0.191 g) and NaH 2 mmol (0.048 g)

It was added to 150 mL of water C ₆ H ₁₂ (99.5%) and refluxed at 30 ° C. to 40 ° C. until no more H ₂ was generated. 1 mmol (0.223 g) of EuCl ₂ was added thereto, and [Eu (BEHP) (DPP)] was synthesized as in Example 2.

Example 9 Preparation of [Eu (PC-88A) (DPP)] Phosphor According to the Invention

A phosphor was synthesized according to the following scheme.

EuCl ₂ (99.99%), PC88A-H (98%, C ₁₆ H ₃₅ O ₃ P.) and DPP-H (99%, diphenylphosphic acid, Aldrich Co) were used without purification. 1 mmol (0.306 g) of PC88A-H and 1 mmlo (0.191 g) of DPP-H are added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%, anhydrous), and refluxed at about 30 to 40 ℃ for 3 hours. 1 mmol (0.223 g) of EuCl ₂ was added, and the mixture was kept at 30 ° C. to 40 ° C. and stirred for about 3 days (72 hours) until all of the EuCl ₂ crystals were dissolved in reflux. After the reaction solution was filtered using a b㎻chner funnel, the material on the filter paper was discarded and the solution was placed in a vacuum pump to evaporate the solvent. 150 mL of anhydrous C ₆ H ₁₂ was added to this material to dissolve it, and the solvent was obtained by evaporation at room temperature. The material thus obtained emitted a blue strong fluorescence when viewed in a 325 nm fluorescent lamp in the form of a soft powder.

The molecular formula of the complex thus synthesized was confirmed by elemental analysis [Eu (PC88A) (DPP)]. Theoretical and experimental values for the mass% of representative elements are as follows.

Theory: Eu 22.5%, P 9.2%.

Experimental Value: Eu 21.3%, P 9.5%.

In the synthesized [Eu (PC88A) (DPP)] phosphors, PC88A and DPP, each having a-charge resonant structure, act as double coordination ligands, respectively, to satisfy stable 4-coordinate bonds with Eu (II) ions. Is the same as

Example 10 Preparation of [Eu (PC-88A) (DPP)] Phosphor According to the Invention

Phosphor was synthesized through an alkali alkali phosphate according to the following scheme.

1 mmol of PC88A-H (0.306), 1 mmlo of DPP-H (0.191 g) and 2 mmol (0.048 g) of NaH were added to 150 mL of anhydrous C ₆ H ₁₂ (99.5%) and H ₂ was Reflux until no longer occurring. EuCl ₂ 1 mmol (0.223 g) was added thereto and synthesized [Eu (PC88A) (DPP)] as in Example 4.

Example 11: [Eu (BEHP) ₂ Luminescence and excitation spectra of complexes

The luminescence spectra of the [Eu (BEHP) ₂ ] complexes prepared in Examples 1 to 3 were measured. 1 shows the luminescence spectrum of the [Eu (BEHP) ₂ ] complex prepared in Example 1. FIG. [Eu (BEHP) ₂ ] complex excited by UV light emits strong blue fluorescence corresponding to 350-550 nm region, and characteristically shows two peak points at 410.8 nm and 434.9 nm. The weak red luminescence in the 580-620 nm region is caused by Eu (III). This shows that only a part of Eu (II) was oxidized to Eu (III).

2 and 3 show the luminescence spectra of the [Eu (BEHP) ₂ ] complexes prepared in Examples 2 and 3, respectively. Unlike in FIG. 1, no red luminescence in the 580-620 nm region caused by Eu (III) was observed. This shows that the synthesis method of Examples 2 and 3 produces stable Eu (II) complexes.

4 is an excited spectrum of the blue luminescence of the [Eu (BEHP) ₂ ] complex prepared in Example 3. FIG. Strong blue luminescence is emitted by absorbing energy corresponding to the 300-420 nm region, and in particular, blue luminescence of maximum intensity is emitted by 376.8 nm.

Example 12: [Eu (PC88A) ₂ Luminescence and excitation spectra of complexes

The luminescence and excitation spectrum of the [Eu (PC88A) ₂ ] complexes prepared in Examples 4 to 6 were measured. 5 is a luminescence spectrum of the [Eu (PC88A) ₂ ] complex prepared in Example 4 measured at room temperature while irradiating UV light. [Eu (PC88A) ₂ ] complex excited by UV light emits strong blue fluorescence corresponding to a region of 390-470 nm, and a peak point is shown at 422 nm. In addition, the red luminescence in the 580-620 nm region was caused by Eu (III). This indicates that only a part of Eu (II) was oxidized to Eu (III), and the fluorescence of Eu (III) was higher than that of Example 1. 6 and 7 are luminescence spectra of the [Eu (PC88A) ₂ ] complexes prepared in Examples 5 and 6. FIG. Unlike FIG. 5, no red luminescence was observed in the 580-620 nm region caused by Eu (III). This shows that the synthesis method of Examples 5 and 6 produced stable Eu (II) complexes.

8 is an excitation spectrum for the blue luminescence of the [Eu (PC88A) ₂ ] complex. Strong blue luminescence is emitted by absorbing energy corresponding to the 300-400 nm region, and in particular, blue luminescence of maximum intensity is emitted by 365 nm.

Example 13: Luminescence and excitation spectra of [Eu (BEHP) (DPP)] complexes

The luminescence and excitation spectra of the [Eu (BEHP) (DPP)] complexes prepared in Examples 7 and 8 were measured. 9 shows the luminescence spectrum of the [Eu (BEHP) (DPP)] complex measured at room temperature while irradiating UV light. [Eu (BEHP) (DPP)] complexes excited by UV light emit strong blue fluorescence corresponding to the region of 380-470 nm, and characteristically show one peak at 422 nm. The weak red luminescence in the 580-620 nm region is caused by Eu (III).

10 is an excited spectrum for the blue luminescence of the [Eu (BEHP) (DPP)] complex. By absorbing energy corresponding to the region of 275-400 nm, a strong blue luminescence is emitted, in particular, a blue luminescence of maximum intensity is emitted by 360 nm.

Example 14 Luminescence and Excited Spectrum of [Eu (PC88A) (DPP)] Complexes

The luminescence and excitation spectra of the [Eu (PC88A) (DPP)] complexes prepared in Examples 9 and 10 were measured. Regardless of Examples 9 and 10, the [Eu (PC88A) (DPP)] complexes showed the same spectrum. 11 is a luminescence spectrum of the [Eu (PC88A) ₂ ] complex measured at room temperature while irradiating UV light. [Eu (PC88A) (DPP)] complexes excited by UV light emit strong blue fluorescence corresponding to a region of 380-470 nm, and a peak point is shown at 422 nm. In addition, no red luminescence appeared in the 580-620 nm region.

12 is an excited spectrum for the blue luminescence of the [Eu (PC88A) (DPP)] complex. Strong blue luminescence is emitted by absorbing energy corresponding to the region of 275-400 nm, and blue luminescence of maximum intensity is emitted by 342 nm.

Example 15 [Eu (BEHP) according to the present invention ₂ Polymer brand and thin film manufacturing

Using the [Eu (BEHP) ₂ ] complex and polymer prepared in Example 3, the [Eu (BEHP) ₂ ] / polymer brand was prepared as follows. The polymers used were polystyrene (Pst), poly vinyl acetate (PVA), poly methyl methacrylate (PMMA) and poly ethylene glycol (PEG). 0.1 g and 0.2 g of [Eu (BEHP) ₂ ] complex and polymer were mixed in 80 mL of CH ₂ Cl ₂ organic solvent. Stir for about 1 hour until a uniform solution. The solvent CH ₂ Cl ₂ of this mixed solution was evaporated in an evaporator to give the film [Eu (BEHP) ₂ ] / polymer brand in the form of a film. The brand was dried in an 80 ° C. electric oven.

A thin film of the manufactured brand was molded on a quartz slide substrate as follows. The quartz substrate was immersed in a 2-propanol solution in which KOH was saturated and washed, and then washed again with an ultrasonic wave in 1 M nitric acid solution. The substrates were washed alternately with ethanol and acetone and then dried in an 80 ° C. electric oven. Tape was attached to one side of the substrate and then immersed in a small amount of dissolved branded CH ₂ Cl ₂ solvent for 2 seconds and then removed. After drying in air, the father tape was removed. Figure 13 shows a side-view of the substrate measured by FE-SEM. As shown in FIG. 13, the thickness of the thin film formed on the substrate is about 1.79 to 1.94 μm, and it can be seen that the thin film is formed evenly.

Example 16: [Eu (PC88A) according to the invention ₂ Polymer brand and thin film manufacturing

[Eu (PC88A) ₂ ] / polymer brand was prepared in the same manner as in Example 15 using the [Eu (PC88A) ₂ ] complex and the polymer prepared in Example 6. The polymers used were polystyrene (Pst), poly vinyl acetate (PVA), poly methyl methacrylate (PMMA) and poly ethylene glycol (PEG), as in Example 15.

A prepared thin film of [Eu (PC88A) ₂ ] / polymer brand was formed on a quartz slide substrate in the same manner as in Example 15.

Example 17 [Eu (BEHP) according to the present invention ₂ ] / Luminescence Measurement of Polymer Brands

FIG. 14 shows an image of [Eu (BEHP) ₂ ] / polymer brand thin film taken while irradiating a UV lamp of 365 nm. The thin film emits bright blue fluorescence. 15 is the luminescence spectrum of the [Eu (BEHP) ₂ ] / polymer brand thin film. The relative intensity of luminescence is shown in Table 1 below.

Comparison of luminescence relative intensity of [Eu (BEHP) ₂ ] / polymer brand thin films. Polymer Relative strength No blend
Pst
PVA
PMMA
PEG One
1.3
1.7
0.7
1.3

As shown in Table 1, among the polymers used, PVA increased the luminescence intensity by about 1.7 times, whereas PMMA rather decreased the luminescence intensity by 0.7 times.

Example 18 [Eu (PC88A) according to the invention ₂ ] / Luminescence Measurement of Polymer Brands

FIG. 16 is a luminescence spectrum of [Eu (PC88A) ₂ ] / polymer brand thin film, and the relative intensities of the luminescence for the [Eu (PC88A) ₂ ] thin film are shown in Table 2.

Comparison of luminescence relative strength of [Eu (PC88A) ₂ ] / polymer brand thin films. Polymer Relative strength No blend
Pst
PVA
PMMA
PEG One
13.8
0.9
10.3
8.8

As shown in Table 2, luminous relative strength of [Eu (PC88A) _2] / brand polymer thin film has shown the different results and [Eu (BEHP) 2] / polymer brand. Of the polymers used, Pst increased the luminescence intensity by about 13.8 times, while PVA rather decreased the luminescence intensity by 0.9 times.

Claims (11)

Divalent europium transition metal complex represented by Formula 1 or Formula 2 below
<Formula 1>

<Formula 2>

In Formula 1 or Formula 2,
R ^I and R ^II bonded to the phosphorus atom are each a phenyl group, and R ^III and R ^IV are each any one alkyl group selected from 1 to 12 carbon atoms which may be the same or different, or any one selected from 1 to 12 carbon atoms. Is an alkoxy group.
delete delete delete 1) preparing a europium halide salt having a divalent oxidation number;
2) directly reacting the europium halide salt with organic phosphoric acid in an organic solvent containing no oxygen atom to reflux to generate an Eu (II) / organic phosphoric acid complex and generating hydrogen chloride as a side reaction product;
3) A process for producing the Eu (II) / organophosphate complex according to claim 1, comprising the step of purifying the resulting Eu (II) / organophosphate complex.
1) preparing a europium halide salt having a divalent oxidation number;
2) converting the organophosphoric acid to an alkali metal salt of organophosphoric acid by deprotonation with a base;
3) reacting the alkali metal salt of the organophosphoric acid obtained in step 2 with the europium halide salt of step 1) to produce an Eu (II) / organophosphate complex and generating an alkali metal-halide salt as a side reaction;
4) A process for producing the Eu (II) / organophosphate complex according to claim 1, comprising the step of purifying the resulting Eu (II) / organophosphate complex.

1) preparing a europium oxide (Eu ₂ O ₃ ) having a trivalent oxidation number;
2) reacting the europium oxide (Eu ₂ O ₃ ) with hydrochloric acid to obtain an aqueous solution containing europium ions having a divalent oxidation state;
3) Eu (II) / organic phosphate complex is formed by refluxing an aqueous solution containing europium ions having a + 2-valent oxidation state obtained in step 2 and organic phosphoric acid in an organic solvent containing no oxygen atom. Generating hydrogen as a side reaction;
4) A process for producing the Eu (II) / organophosphate complex according to claim 1, comprising the step of purifying the resulting Eu (II) / organophosphate complex.

Blue phosphor comprising the Eu (II) / organophosphate complex of Formula 1 or Formula 2
A method of manufacturing a thin film, wherein the blue phosphor and the polymer of claim 8 are branded and dissolved in an organic solvent to prepare a thin film.
The method of claim 9, wherein the polymer is any one selected from polystyrene, PVA, PMMA, and PEG.
Phosphor composition obtained by branding the blue phosphor of claim 8 and a polymer

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