JP6925620B2 - Platinum complex and luminescent material containing it - Google Patents

Description

The present invention relates to a platinum complex and a luminescent material containing the platinum complex.

Phosphorescent luminescence by an organic metal complex can theoretically achieve higher quantum efficiency than fluorescent luminescence in organic EL (electroluminescence). Therefore, the organometallic complex is expected as a material for a functional element such as an organic light emitting element, which is a next-generation technology, specifically, a material for an organic EL display and the like. As the organometallic complex, a complex such as iridium, platinum, or ruthenium is known. Among them, the iridium complex is widely used as a highly efficient phosphorescent light emitting material. However, iridium is a rare element and its reserves are small. Therefore, in recent years, platinum complexes have been attracting attention as a phosphorescent light emitting material instead of iridium.

As the platinum complex, an organic platinum complex containing a platinum atom coordinated by four bidentate ligands, an organic platinum complex containing a platinum atom coordinated by two bidentate ligands, and one bidentate Known are organic platinum complexes containing platinum atoms coordinated with a position and two monodentate ligands, and organic platinum complexes containing platinum atoms coordinated with one tetradentate ligand. As an organic platinum complex containing a platinum atom coordinated by one bidentate ligand and two bidentate ligands, one iminopyrazole (bidentate ligand) and two monodentate ligands An organic platinum complex containing a platinum atom coordinated with four ligands containing the above is known (Non-Patent Document 1). However, there is no report on the luminescence of this organic platinum complex.

Marc-Etienne Moret and Peter Chen, Organometallics, 2008, Vol. 27, p.4903-4916

Therefore, an object of the present invention is to provide a platinum complex having iminopyrazole as a ligand and having phosphorescent characteristics.

The present invention is a platinum complex represented by the formula (I), the formula (II), the formula (III), or the formula (IV).

In the above formula,
n1 and n2 are independently integers of 2 to 20.
R ¹ and R ² are independently halogen atoms, alkyl groups having 1-22 carbon atoms, alkoxy groups having 2 to 16 carbon atoms, alkynyl groups having 2 to 16 carbon atoms, cycloalkyl groups, and 1 to 1 carbon atoms. Selected from 16 alkoxy groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 2 to 16 carbon atoms, and an alkynyl having 2 to 16 carbon atoms. It is selected from a group, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group. ..

Further, the present invention is a luminescent material containing one or more selected from the group consisting of platinum complexes represented by formulas (I), (II), (III), and (IV).

In the above formula,
n1 and n2 are independently integers of 2 to 20.
R ¹ and R ² are independently halogen atoms, alkyl groups having 1-22 carbon atoms, alkoxy groups having 2 to 16 carbon atoms, alkynyl groups having 2 to 16 carbon atoms, cycloalkyl groups, and 1 to 1 carbon atoms. Selected from 16 alkoxy groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 2 to 16 carbon atoms, and an alkynyl having 2 to 16 carbon atoms. It is selected from a group, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group. ..

The light emitting material containing the platinum complex of the present invention has an advantage that the light emitting intensity is strong even in a solution state.

FIG. 1 shows the emission characteristics of the compound (1), the compound (3) and the compound (4) in the crystalline state at 298K. FIG. 2 shows the emission characteristics of the compound (1), the compound (3) and the compound (4) in the crystalline state at 77K. FIG. 3 shows the emission characteristics of the compound (1) in the amorphous state and the crystalline state at 298K. FIG. 4 shows the emission characteristics of the compound (1) in the amorphous state and the crystalline state at 77K. FIG. 5 shows the molecular structure of compound (1). FIG. 6 is a packing diagram of compound (1) in a crystal. FIG. 7 shows the molecular structure of compound (3). FIG. 8 is a packing diagram of compound (3) in a crystal. FIG. 9 is a UV spectrum when an acid is added to the solution of compound (1). FIG. 10 is an emission spectrum when methanesulfonic acid is added to the solution of compound (1). FIG. 11 is an image of a solution of compound (1) to which methanesulfonic acid has been added.

The present inventors have stated that when bis (pyrazoleimine) platinum is used as the mother skeleton, the luminescence intensity is strong even in a solution state dissolved in a solvent, and further, the luminescence intensity is strong even in a solution state and at room temperature. I found it unexpectedly. Based on this finding, the present inventors have completed the present invention.

The platinum complex of the present invention is represented by the formula (I), the formula (II), the formula (III), or the formula (IV).

In the above formula,
n1 and n2 are independently integers of 2 to 20.
R ¹ and R ² are independently halogen atoms, alkyl groups having 1-22 carbon atoms, alkoxy groups having 2 to 16 carbon atoms, alkynyl groups having 2 to 16 carbon atoms, cycloalkyl groups, and 1 to 1 carbon atoms. Selected from 16 alkoxy groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 2 to 16 carbon atoms, and an alkynyl having 2 to 16 carbon atoms. It is selected from a group, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group. ..

The platinum complex of the present invention is a planar platinum complex having two iminopyrazole as ligands. This platinum complex has high quantum luminous efficiency in the solution state. Further, the platinum complexes represented by the formulas (I) and (II), which are ring-crossing complexes in which two iminopyrazole as ligands are crosslinked with alkylene, show high luminous efficiency even in the solid state. .. It has not been reported that ordinary platinum complexes have high luminous efficiency in such a solid state.

The platinum complex having iminoimidazole as a ligand, which is a positional isomer of the nitrogen element of the platinum complex of the present invention, does not exhibit luminescence. Considering this, in the platinum complex of the present invention, the nitrogen atom of iminopyrazole, which is a ligand, forms an intramolecular hydrogen bond with another hydrogen atom of iminopyrazole in the molecule, and the metal plane is rigid. It is considered that high light emission efficiency is realized by the conversion.

In the present invention, the term "halogen atom" means fluorine, chlorine, bromine or iodine. Fluorine is preferable as the halogen atom.

In the present invention, the term "alkyl group having 1 to 16 carbon atoms" means, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like. Hexadecyl and the like can be mentioned. The alkyl group may be linear or branched. The alkyl group having 1 to 16 carbon atoms is preferably an alkyl group having 1 to 13 carbon atoms, more preferably 1 to 8 carbon atoms, and further preferably 1 to 5 carbon atoms.

In the present invention, the term "alkyl group having 1 to 32 carbon atoms" means, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like. Hexadecyl and the like can be mentioned. The alkyl group may be linear or branched. The alkyl group having 1 to 32 carbon atoms is preferably an alkyl group having 4 to 24 carbon atoms, more preferably 4 to 20 carbon atoms, and further preferably 5 to 16 carbon atoms.

In the present invention, the term "alkenyl group having 2 to 16 carbon atoms" means vinyl, allyl, isopropenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decynyl, undecynyl, dodecynyl, tridodecynyl, tetradecynyl, pentadecynyl, Examples thereof include a linear or branched alkenyl group having 2 to 16 carbon atoms such as hexadecynyl. The alkynyl group having 2 to 16 carbon atoms is preferably an alkenyl group having 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and further preferably 2 to 8 carbon atoms. In the term "alkenyl group having 2 to 16 carbon atoms", the position of the double bond is not limited.

In the present invention, the term "alkynyl group having 2 to 16 carbon atoms" refers to a linear or branched alkynyl group having 2 to 16 carbon atoms such as acetylenyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, and octynyl. Can be mentioned. The alkynyl group having 2 to 16 carbon atoms is preferably an alkynyl group having 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and further preferably 2 to 8 carbon atoms. In the term "alkynyl group having 2 to 16 carbon atoms", the position of the triple bond is not limited.

In the present invention, the term "alkoxy group having 1 to 16 carbon atoms" is an alkyloxy group. The alkyl moiety of this alkyloxy group is the same as that of the alkyl group having 1 to 16 carbon atoms. Examples of the alkoxyl group include methoxy, ethoxy, propyloxy, butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy, tetradecyloxy and pentadecyloxy. , Hexadecyloxy and the like. The "alkoxy group having 1 to 16 carbon atoms" is preferably an alkoxy group having 1 to 13 carbon atoms, more preferably 1 to 8 carbon atoms, and further preferably 1 to 5 carbon atoms.

In the present invention, the term "alkylamino group" is a linear and branched alkylamino group. Examples of the "alkylamino group" include methylamino, ethylamino, propylamino, butylamino, pentylamino, hexylamino, heptylamino, octylamino, nonylamino, decylamino, undecylamino, dodecylamino, tridecylamino and tetra. Examples thereof include decylamino, pentadecylamino and hexadecylamino. The alkyl group of the "alkylamino group" may be linear or branched. The alkyl group of the "alkylamino group" is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 13 carbon atoms, and further preferably 1 to 8 carbon atoms.

In the present invention, the term "alkoxycarbonyl group" is an alkyloxycarbonyl group. The alkyl moiety of this alkyloxycarbonyl group is the same as the alkyl group having 1 to 16 carbon atoms. Examples of the alkoxylcarbonyl group include methoxycarbonyl, ethoxycarbonyl, propyloxycarbonyl, butyloxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl and undecyloxycarbonyl. , Dodecyloxycarbonyl, tridecyloxycarbonyl, tetradecyloxycarbonyl, pentadecyloxycarbonyl, hexadecyloxycarbonyl and the like. The "alkoxycarbonyl group" is preferably an alkoxycarbonyl group containing an alkoxy moiety having 1 to 13 carbon atoms, more preferably an alkoxy partial alkoxycarbonyl group having 1 to 8 carbon atoms, and further preferably an alkoxy moiety having 1 to 5 carbon atoms. It is an alkoxycarbonyl group containing.

In the present invention, the term "cycloalkyl group" is an alicyclic hydrocarbon group having 5 to 8 carbon atoms. Examples of the "cycloalkyl group" include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like. The "cycloalkyl group" is preferably a cycloalkyl group having 5 to 7 carbon atoms, and more preferably a cycloalkyl group having 5 to 6 carbon atoms.

Of the platinum complexes, R ¹ and R ² are preferably platinum complexes represented by the formula (III) or the formula (IV), which are alkyl groups having 1 to 32 carbon atoms, respectively.

Among the platinum complexes, R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are preferably platinum complexes represented by formulas (I), formulas (II), formulas (III) or formulas (IV), which are hydrogen atoms. ..

Of the platinum complexes, n1 and n2 are preferably platinum complexes represented by the formula (I) or the formula (II), which are integers of 8 to 15, respectively.

In the platinum complex represented by the formula (I), n1 is preferably an integer of 8 to 15, more preferably an integer of 9 to 13, and even more preferably an integer of 9 to 12. In the platinum complex represented by the formula (I), R ¹¹ is preferably a hydrogen atom. In the platinum complex represented by the formula (I), n1 is preferably an integer of 8 to 15 and R ¹¹ is a hydrogen atom, and more preferably n1 is 9 to 9. It is an integer of 13, and R ¹¹ is a hydrogen atom, more preferably n1 is an integer of 9 to 12, and R ¹¹ is a hydrogen atom.

In the platinum complex represented by the formula (II), n2 is preferably an integer of 8 to 15, more preferably an integer of 9 to 13, and even more preferably an integer of 9 to 12. In the platinum complex represented by the formula (II), R ¹² is preferably a hydrogen atom. In the platinum complex represented by the formula (II), n2 is preferably an integer of 8 to 15 and R ¹² is a hydrogen atom, and more preferably n2 is 9 to 9. It is an integer of 13, and R ¹² is a hydrogen atom, more preferably n2 is an integer of 9 to 12, and R ¹² is a hydrogen atom.

In the platinum complex represented by the formula (III), R ¹ is preferably an alkyl group having 1 to 32 carbon atoms, more preferably an alkyl group having 4 to 24 carbon atoms, and further preferably 4 carbon atoms. ~ 20 alkyl groups. In the platinum complex represented by the formula (III), R ¹³ is preferably a hydrogen atom. In the formula, the platinum complex represented by the formula (III) preferably has R 1 as an alkyl group having ^{1 to 32 carbon atoms and R 13} as a hydrogen atom, more preferably R. ¹ is an alkyl group having 4 to 24 carbon atoms, and R ¹³ is a hydrogen atom, more preferably R ¹ is an alkyl group having 4 to 20 carbon atoms, and R ¹³ is hydrogen. It is an atom.

In the platinum complex represented by the formula (IV), R ² is preferably an alkyl group having 1 to 32 carbon atoms, more preferably an alkyl group having 4 to 24 carbon atoms, and further preferably 4 carbon atoms. ~ 20 alkyl groups. In the platinum complex represented by the formula (IV), R ¹⁴ is preferably a hydrogen atom. In the formula, the platinum complex represented by the formula (IV) preferably has R ² as an alkyl group having 1 to 32 carbon atoms and R ¹⁴ as a hydrogen atom, more preferably R. ² is an alkyl group having 4 to 24 carbon atoms and R ¹⁴ is a hydrogen atom, more preferably R ² is an alkyl group having 4 to 20 carbon atoms and R ¹⁴ is an alkyl group having 4 to 20 carbon atoms. , A hydrogen atom.

Further, among the platinum complexes, a platinum complex represented by the formula (1), the formula (2), the formula (3) or the formula (4) is preferable.

Further, the present invention is a luminescent material containing one or more selected from the group consisting of platinum complexes represented by formulas (I), (II), (III), and (IV).

In the above formula,
n1 and n2 are independently integers of 2 to 20.
R ¹ and R ² are independently halogen atoms, alkyl groups having 1-22 carbon atoms, alkoxy groups having 2 to 16 carbon atoms, alkynyl groups having 2 to 16 carbon atoms, cycloalkyl groups, and 1 to 1 carbon atoms. Selected from 16 alkoxy groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹¹ , R ¹² , R ¹³ and R ¹⁴ independently have a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 2 to 16 carbon atoms, and an alkynyl having 2 to 16 carbon atoms. It is selected from a group, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group. ..

Of the platinum complexes, R ¹ and R ² are independently selected from the group consisting of platinum complexes represented by formulas (III) and (IV), which are alkyl groups having 1 to 32 carbon atoms, respectively. A light emitting material containing 1 or more is preferable.

Among the platinum complexes, R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are composed of platinum complexes represented by formulas (I), formulas (II), formulas (III) and formulas (IV), which are hydrogen atoms. A luminescent material containing one or more selected from the group is preferred.

Of the platinum complexes, n1 and n2 independently contain one or more selected from the group consisting of platinum complexes represented by formulas (I) and (II), which are integers of 8 to 15, respectively. The material is preferred.

In the platinum complex represented by the formula (I) contained in the luminescent material, n1 is preferably an integer of 8 to 15, more preferably an integer of 9 to 13, and even more preferably an integer of 9 to 12. be. In the platinum complex represented by the formula (I) contained in the light emitting material, R ¹¹ is preferably a hydrogen atom in the formula. In the formula, the platinum complex represented by the formula (I) contained in the light emitting material preferably has n1 as an integer of 8 to 15 and R ¹¹ as a hydrogen atom, more preferably. n1 is an integer of 9 to 13 and R ¹¹ is a hydrogen atom, more preferably n1 is an integer of 9 to 12 and R ¹¹ is a hydrogen atom.

In the platinum complex represented by the formula (II) contained in the luminescent material, n2 is preferably an integer of 8 to 15, more preferably an integer of 9 to 13, and even more preferably an integer of 9 to 12. be. In the platinum complex represented by the formula (II) contained in the light emitting material, R ¹² is preferably a hydrogen atom. In the formula, the platinum complex represented by the formula (II) contained in the light emitting material preferably has n2 as an integer of 8 to 15 and R ¹² as a hydrogen atom, more preferably. n2 is an integer of 9 to 13 and R ¹² is a hydrogen atom, more preferably n2 is an integer of 9 to ¹² and R 12 is a hydrogen atom.

In the platinum complex represented by the formula (III) contained in the light emitting material, R ¹ is preferably an alkyl group having 1 to 32 carbon atoms, more preferably an alkyl group having 4 to 24 carbon atoms, and further. It is preferably an alkyl group having 4 to 20 carbon atoms. In the platinum complex represented by the formula (III) contained in the light emitting material, R ¹³ is preferably a hydrogen atom. In the formula, the platinum complex represented by the formula (III) contained in the light emitting material preferably has R 1 as an alkyl group having ^{1 to 32 carbon atoms and R 13} as a hydrogen atom. More preferably, R ¹ is an alkyl group having 4 to 24 carbon atoms, R ¹³ is a hydrogen atom, and more preferably R ¹ is an alkyl group having 4 to 20 carbon atoms. R ¹³ is a hydrogen atom.

In the platinum complex represented by the formula (IV) contained in the light emitting material, R ² is preferably an alkyl group having 1 to 32 carbon atoms, more preferably an alkyl group having 4 to 24 carbon atoms, and further. It is preferably an alkyl group having 4 to 20 carbon atoms. In the platinum complex represented by the formula (IV) contained in the light emitting material, R ¹⁴ is preferably a hydrogen atom. In the formula, the platinum complex represented by the formula (IV) contained in the light emitting material preferably has R ² as an alkyl group having 1 to 32 carbon atoms and R ¹⁴ as a hydrogen atom. More preferably, R ² is an alkyl group having 4 to 24 carbon atoms, and R ¹⁴ is a hydrogen atom, and even more preferably, R ² is an alkyl group having 4 to 20 carbon atoms. And R ¹⁴ is a hydrogen atom.

Further, a luminescent material containing 1 or more selected from the group consisting of platinum complexes represented by the formulas (1), (2), (3) and (4) is preferable. This is because these platinum complexes have strong luminescence intensity even in a solution state dissolved in a solvent, and further have strong luminescence intensity even in a crystalline state and at room temperature.

The platinum complex (I) of the present invention can be produced, for example, as follows.

In the above formula, n1 is an integer of 2 to 20.
R ¹¹ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, and the like. It is selected from an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group.

The compound of the formula (XII) and the platinum compound (V) are reacted in the presence of a base to obtain the compound of the formula (I). Examples of this platinum compound include PtCl ₂ (CH ₃ CN) ₂ and K ₂ PtCl ₄ . As the base, for example, K ₂ CO ₃ , NaH, triethylamine and the like may be used. This reaction is carried out, for example, at 20 to 130 ° C. for 1 to 48 hours. Examples of the solvent for this reaction include, but are not limited to, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), a mixture of toluene and DMSO, and the like.

The compound represented by the formula (XII) may be commercially available or may be home-made by referring to publicly known documents. The compound represented by the formula (XII) is obtained by heating, for example, an aldehyde derivative of the formula (XA) and a diamine (compound of the formula (XIA)) in an amount of 0.5 equivalent to the aldehyde derivative in a solvent. To obtain the compound of formula (XII). This reaction is carried out, for example, at 20 to 100 ° C. for a required time. Examples of the solvent for this reaction include, but are not limited to, methanol, ethanol, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), and the like.

The platinum complex (II) of the present invention can be produced, for example, as follows.

In the above formula, n2 is an integer of 2 to 20.
R ¹² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, and the like. It is selected from an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group.

The compound of the formula (XIII) and the platinum compound (V) are reacted in the presence of a base to obtain the compound of the formula (II). Examples of this platinum compound include PtCl ₂ (CH ₃ CN) ₂ and K ₂ PtCl ₄ . As the base, for example, K ₂ CO ₃ , NaH, triethylamine and the like may be used. This reaction is carried out, for example, at 20 to 130 ° C. for 1 to 48 hours. Examples of the solvent for this reaction include, but are not limited to, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), a mixture of toluene and DMSO, and the like.

The compound represented by the formula (XIII) may be commercially available or may be home-made by referring to publicly known documents. The compound represented by the formula (XIII) is obtained by heating, for example, an aldehyde derivative of the formula (XVIA) and a diamine (compound of the formula (XIB)) in an amount of 0.5 equivalent to the aldehyde derivative in a solvent. To obtain the compound of formula (XIII). This reaction is carried out, for example, at 20 to 100 ° C. for a required time. Examples of the solvent for this reaction include, but are not limited to, methanol, ethanol, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), and the like.

The platinum complex (III) of the present invention can be produced, for example, as follows.

In the above formula,
R ¹ is independently a halogen atom, an alkyl group having 1 to 32 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, and an alkoxy having 1 to 16 carbon atoms. Selected from groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹³ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, and the like. It is selected from an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group.

The compound of the formula (XV) and the platinum compound (V) are reacted in the presence of a base to obtain the compound of the formula (III). Examples of this platinum compound include PtCl ₂ (CH ₃ CN) ₂ and K ₂ PtCl ₄ . As the base, for example, K ₂ CO ₃ , NaH, triethylamine and the like may be used. This reaction is carried out, for example, at 20 to 130 ° C. for 1 to 48 hours. Examples of the solvent for this reaction include, but are not limited to, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), a mixture of toluene and DMSO, and the like.

The compound represented by the formula (XV) may be commercially available or may be home-made by referring to publicly known documents. The compound represented by the formula (XV) is prepared by, for example, heating an aldehyde derivative of the formula (XB) and an amine (compound of the formula (XIVA)) in an amount equivalent to 1 equivalent of the aldehyde derivative in a solvent. Obtain the compound of formula (XV). This reaction is carried out, for example, at 20 to 100 ° C. for a required time. Examples of the solvent for this reaction include, but are not limited to, methanol, ethanol, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), and the like.

The platinum complex (IV) of the present invention can be produced, for example, as follows.

In the above formula,
R ² is independently a halogen atom, an alkyl group having 1 to 32 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, and an alkoxy having 1 to 16 carbon atoms. Selected from groups, amino groups, alkylamino groups, hydroxy groups, carboxyl groups, alkoxycarbonyl groups, phenyl groups, phenoxy groups, nitrile groups, nitro groups or thiol groups.
R ¹⁴ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, a cycloalkyl group, an alkoxy group having 1 to 16 carbon atoms, and the like. It is selected from an amino group, an alkylamino group, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, a phenyl group, a phenoxy group, a nitrile group, a nitro group or a thiol group.

The compound of the formula (XVI) and the platinum compound (V) are reacted in the presence of a base to obtain the compound of the formula (IV). Examples of this platinum compound include PtCl ₂ (CH ₃ CN) ₂ and K ₂ PtCl ₄ . As the base, for example, K ₂ CO ₃ , NaH, triethylamine and the like may be used. This reaction is carried out, for example, at 20 to 130 ° C. for 1 to 48 hours. Examples of the solvent for this reaction include, but are not limited to, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), a mixture of toluene and DMSO, and the like.

The compound represented by the formula (XVI) may be commercially available, or may be home-made by referring to publicly known documents. The compound represented by the formula (XVI) is prepared by, for example, heating an aldehyde derivative of the formula (XVIB) and an amine (compound of the formula (XIVB)) in an amount equivalent to 1 equivalent of the aldehyde derivative in a solvent. Obtain a compound of formula (XVI). This reaction is carried out, for example, at 20 to 100 ° C. for a required time. Examples of the solvent for this reaction include, but are not limited to, methanol, ethanol, a mixture of dimethylformamide (DMF) and methanol, dimethyl sulfoxide (DMSO), and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

Various spectra were measured using the following instruments.
The nuclear magnetic resonance (NMR) spectrum was measured using a UNITY-INOVA nuclear magnetic resonance apparatus (500 MHz) manufactured by Varian, and the residual signal of the measurement solvent was used as an internal reference.

The quantum yield was measured using a fluorometer FP-6500N, a low-temperature medium-integrating sphere system INK-533 compatible with phosphorescence measurement, and a liquid sample cell LPH-120 (all manufactured by JASCO Corporation).

The following abbreviations are used in the description herein.
DMSO: Dimethyl sulfoxide

[Example 1]
Synthesis of trans- [μ-N, N'-dodecamethylenebis (3-iminopyrazolato)] platinum (II) (compound (1))

Compound (1) was synthesized according to Scheme 1. Pyrazole-3-carbaldehyde (X-1) (0.480 g, 5.0 mmol) and 1,12-dodecanediamine (XI-1) (0.501 g, 2.5 mmol) in ethanol (50 mL) for 20 hours. By refluxing and removing the solvent from the reaction solution under reduced pressure, the ligands N, N'-(dodecane-1,12-diyl) bis [1- (1H-pyrazol-5-yl) methaneimine] (XII-1) was obtained as a yellow liquid. This compound (XII-1) was used for the next reaction without further purification.

Subsequently, in an argon atmosphere, compound (XII-1) (0.891 g, 2.50 mmol), PtCl ₂ (CH ₃ CN) ₂ (V-1) (0.870 g, 2.50 mmol) and K ₂ CO ₃ (4.146 g, 30.0 mmol) was heated at 120 ° C. for 24 hours in a mixed solvent of toluene (300 mL) and DMSO (75 mL). Then, the solid produced by removing toluene from the reaction solution under reduced pressure was collected by filtration. The resulting solid was dissolved in ethyl acetate (400 mL) and the solution was washed 3 times with saturated brine (200 mL) to remove DMSO. After washing, the collected organic layer was _{dried over Na 2} SO ₄ , filtered, and concentrated under reduced pressure to obtain a crude product. The obtained crude product is purified by silica gel column chromatography (NH-SiO ₂ , eluate: CH ₂ Cl ₂ / hexane = 3: 7) to obtain the compound represented by the chemical formula (1) as a yellow solid. (0.345 g, 25%).

^{1 1} H NMR (500 MHz, CDCl ₃ ) δ = 0.93-1.05 (m, 2H), 1.12-1.41 (m, 14H), 1.55-1.65 (m, 2H), 2.20−2.31 (m, 2H), 3.39 ( ddd, J = 11.1, 11.1, 3.0 Hz, 2H), 5.34 (dddd, J = 11.1, 4.7, 3.9, 1.1 Hz Hz, 2H), 6.62 (d, J = 2.1 Hz, 2H), 7.68 (d, J = 2.1 Hz, 2H), 7.84 (s, 2H) ppm;
¹³ C NMR δ = 22.9, 26.92, 26.96, 27.3, 60.0, 107.6, 138.9, 148.7, 161.1 ppm;
IR (KBr) 2923, 2855, 1605, 1417, 1353, 1148, 1035, 929, 748, 697 cm- ¹ ;
For HRMS (FAB) m / z C ₂₀ H ₃₁ N ₆ ¹⁹⁵ Pt Calculated: 550.2258; Measured: 550.2267 [M + H] ⁺ .

[Example 2]
Production of trans- [μ-N, N'-dodecamethylenebis (3-iminoindazolate)] platinum (II) (compound (2))

Compound (2) was synthesized according to Scheme 2. Indazole-3-carbaldehyde (XVI-1) (0.153 g, 1.05 mmol) and 1,12-dodecanediamine (XI-1) (0.108 g, 0.539 mmol) in ethanol (4.0 mL). By refluxing for 3 hours and removing the solvent from the reaction solution under reduced pressure, the ligand N, N'-(dodecane-1,12-diyl) bis [1- (1H-indazole-5-yl) Methanimine] (XIII-1) was obtained as a yellow liquid. This compound (XIII-1) was used for the next reaction without further formation.

Subsequently, in an argon atmosphere, compound (XIII-1) (0.360 g, 2.0 mmol), PtCl ₂ (CH ₃ CN) ₂ (V-1) (176.2 mg, 0.506 mmol) and K ₂ CO ₃ (854.8 mg, 6.07 mmol) was heated at 120 ° C. for 24 hours in a mixed solvent of toluene (100 mL) and DMSO (2.4 mL). Then, the solid produced by removing toluene from the reaction solution under reduced pressure was collected by filtration. The resulting solid was dissolved in ethyl acetate (100 mL) and the solution was washed 3 times with saturated brine (100 mL) to remove DMSO. After washing, the collected organic layer was _{dried over Na 2} SO ₄ , filtered, and concentrated under reduced pressure to obtain a crude product. The obtained crude product is purified by silica gel column chromatography (NH-SiO ₂ , eluate: hexane / ethyl acetate = 4: 1) and subsequently subjected to GPC to carry out the compound represented by the chemical formula (2). Was obtained as a red solid (93.0 g, 42%).

^{1 1} H NMR (500 MHz, CDCl ₃ ): δ = 0.73-0.83 (br, 2H), 0.92-1.24 (m, 14H), 1.40-1.50 (m, 2H), 2.00-2.11 (m, 2H), 2.85 (td, J = 11.5, 2.4 Hz, 2H), 5.44 (dt, J = 11.5, 3.7 Hz, 2H), 6.87 (s, 2H), 7.23-7.30 (m, 4H), 7.61-7.66 (m, 2H) ), 7.90-7.95 (m, 2H) ppm;
¹³ C NMR (125MHz, CDCl ₃ ): δ = 22.8, 26.8, 26.9, 29.0, 59.7, 117.4, 119.1, 123.1, 123.1, 141.3, 150.2, 157.6 ppm;
HRMS (APCI): m / z [M + H] ⁺ C ₂₈ H ₃₄ N ₆ Pt Calculated value: 650.2568; Measured value: 650.2559.

[Example 3]
Production of trans- [N-Pentyl (3-iminopyrazolato)] Platinum (II) (Compound (3))

Compound (3) was synthesized according to Scheme 3. Pyrazole-3-carbaldehyde (X-1) (0.480 g, 5.0 mmol) and pentylamine (XIV-1) (0.436 g, 5.0 mmol) were refluxed in ethanol (30 mL) for 24 hours. By removing the solvent from the reaction solution under reduced pressure, the ligand N-pentyl-1- (1H-pyrazole-5-yl) methanimine (XV-1) was obtained as a yellow liquid. This compound (XV-1) was used for the next reaction without further purification.

Subsequently, the compound (XV-1) (0.360 g, 2.0 mmol), PtCl ₂ (CH ₃ CN) ₂ (V-1) (0.348 g, 1.00 mmol) and K ₂ CO _{3 under an argon atmosphere.} (1.658 g, 12.0 mmol) was heated at 120 ° C. for 24 hours in a mixed solvent of toluene (120 mL) and DMSO (30 mL). Then, the solid produced by removing toluene from the reaction solution under reduced pressure was collected by filtration. The resulting solid was dissolved in ethyl acetate (200 mL) and the solution was washed 3 times with saturated brine (200 mL) to remove DMSO. After washing, the collected organic layer was _{dried over Na 2} SO ₄ , filtered, and concentrated under reduced pressure to obtain a crude product. The obtained crude product is purified by silica gel column chromatography (NH-SiO ₂ , eluate: CH ₂ Cl ₂ / hexane = 2: 3) to turn the compound represented by the chemical formula (3) into an orange color. Obtained as a solid (0.330 g, 63%).

^{1 1} H NMR (500 MHz, CDCl ₃ ) δ = 0.90 (t, J = 7 Hz, 6H), 1.32-1.43 (m, 8H), 1.78-1.86 (m, 4H), 4.26 (t, J = 7 Hz) , 4H), 6.57 (d, J = 2.1 Hz, 2H), 7.65 (d, J = 2.1 Hz, 2H), 7.70 (s, 2H) ppm;
¹³ C NMR δ = 14.0, 22.4, 28.6, 30.9, 59.6, 107.7, 138.4, 148.8, 160.9 ppm;
IR (KBr): 2957, 2939, 2856, 1598, 1467, 1416, 1348, 1212, 1146, 1042, 930, 778, 768, 729, 697 cm- ¹ ;
For HRMS (FAB) m / z C ₁₈ H ₂₉ N ₆ ¹⁹⁵ Pt Calculated: 524.2101; Measured: 524.2097 [M + H] ⁺ .

[Example 4]
Production of trans- [N-hexadecane (3-iminopyrazolato)] platinum (II) (compound (4))

Compound (4) was synthesized according to Scheme 4. Pyrazole-3-carbaldehyde (X-1) (0.38 g, 4.0 mmol) and hexadecaneamine (XIV-2) (0.97] g, 4.0] mmol) in ethanol (50 mL) for 24 hours. By removing the solvent from the refluxed reaction solution under reduced pressure, the ligand N-hexadecane-1- (1H-pyrazole-5-yl) methaneimine (XV-2) was obtained as a yellow liquid. This compound (XV-2) was used for the next reaction without further purification.

Subsequently, in an argon atmosphere, compound (XV-2) (1.28 g, 4.0 mmol), PtCl ₂ (CH ₃ CN) ₂ (V-1) (0.70 g, 2.0 mmol) and K ₂ CO ₃ (3.32 g, 24 mmol) was heated at 120 ° C. for 24 hours in a mixed solvent of toluene (400 mL) and DMSO (100 mL). Then, the solid produced by removing toluene from the reaction solution under reduced pressure was collected by filtration. The resulting solid was dissolved in ethyl acetate (150 mL) and the solution was washed 3 times with saturated brine (200 mL) to remove DMSO. After washing, the collected organic layer was _{dried over Na 2} SO ₄ , filtered, and concentrated under reduced pressure to obtain a crude product. The obtained crude product is purified by silica gel column chromatography (NH-SiO ₂ , eluate: CH ₂ Cl ₂ / hexane = 2: 8) to turn the compound represented by the chemical formula (4) into an orange color. Obtained as a solid (0.27 g, 21%).

^{1 1} H NMR (500 MHz, CDCl ₃ ) δ = 0.89 (t, 6 H), 1.20-1.36 (m, 48 H), 1.36-1.44 (m, 4 H), 1.81-1.90 (m, 4 H), 4.37 (t, 4 H), 6.62 (d, 2 H), 7.66 (d, 2 H), 7.87 (s, 2 H) ppm;
¹³ C NMR δ = 14.1, 22.7, 26.4, 29.3, 29.4, 29.55, 29.59, 29.64, 29.66, 29.67, 29.69, 29.69, 29.69, 31.3, 31.9, 59.7, 107.9, 138.9, 148.8, 161.3 ppm;
IR (KBr): 2919, 2850, 1604, 1465, 1414, 1355, 1211, 1144, 1040, 929, 779, 761, 725, 700 cm- ¹ ;
HRMS (FAB) m / z C ₄₀ H ₇₃ N ₆ ¹⁹⁵ Pt: Calculated value: 832.5544; Measured value: 832.5538 [M + H] ⁺ .

[Measurement of solution emission quantum yield]
The 2-methyltetrahydrofurous solution (2 × 10 ^-4 M) of all the samples in the quartz cell was degassed to remove the influence of oxygen and placed in an argon atmosphere. The measurement at a low temperature (77K) was carried out using a quartz Dewar while cooling the quartz cell with liquid nitrogen. All emission spectra were corrected by using a standard light source. Light having a wavelength of 450 nm was used as the excitation light. A solid quantum efficiency calculation program (manufactured by JASCO Corporation) was used to calculate the internal quantum yield. In addition, the maximum emission wavelength of the light emitted by each platinum complex was also measured. The measurement results are shown in Table 1.

As shown in Table 1, from the results of Examples 1 to 4, the platinum complexes represented by the formulas (I), (II) and (III) are phosphorescent with high quantum efficiency at room temperature in a solution state. It was confirmed that it showed light emission.

[Measurement of solid-state emission quantum yield]
For the compound (1), compound (3) and compound (4) obtained in Example 1, Example 3 and Example 4, the solid emission quantum yield φ (%) at 298K and 77K was measured. Specifically, a crystal obtained by recrystallizing compound (3) from chloroform was used, and a crystal obtained by recrystallizing compound (1) and compound (4) from toluene was used. Then, the emission quantum yield in each crystal state (powder) was determined by an absolute method. The measurement method is as follows.

(Measuring method)
In order to eliminate the influence of oxygen during the measurement, all the samples were filled with crystals (compound (1), compound (3) and compound (4)) as they were in a quartz cell, and an argon stream was aerated for 1 minute. Oxygen was removed, and the measurement was carried out in an argon atmosphere as it was. Further, the measurement at a low temperature (77K) was carried out using a quartz Dewar while cooling the quartz cell in which the crystals were sealed with liquid nitrogen. All emission spectra were corrected by using a standard light source. Light having a wavelength of 420 nm was used as the excitation light. A solid quantum efficiency calculation program (manufactured by JASCO Corporation) was used to calculate the internal quantum yield. In addition, the maximum emission wavelength of the light emitted by each platinum complex was also measured. Table 2 shows the results of the solid-state emission quantum yield and the solid-state emission maximum wavelength.

As shown in Table 2, from the results of Examples 1 and 3, the platinum complex represented by the formulas (I) and (III) exhibits phosphorescence with high quantum efficiency at room temperature in the crystalline state. It could be confirmed.

The emission characteristics of the compound (1), the compound (3) and the crystalline state of the compound (4) are shown in FIGS. 1 and 2. FIG. 1 is measured at 298K and FIG. 2 is measured at 77K.

[Measurement of emission quantum yield in amorphous state]
For the compound (1) obtained in Example 1, the emission quantum yield φ (%) at 298K and 77K was measured. Specifically, the emission quantum yield of compound (1) was determined by an absolute method. The measurement method is as follows.

(Measuring method)
At the time of measurement, in order to eliminate the influence of oxygen, the sample was measured in an argon atmosphere as it was by encapsulating the crystal (compound (1)) as it was in a quartz cell and ventilating an argon air stream for 1 minute to remove oxygen. .. Further, the measurement at a low temperature (77K) was carried out using a quartz Dewar while cooling the quartz cell in which the crystals were sealed with liquid nitrogen. All emission spectra were corrected by using a standard light source. Light having a wavelength of 420 nm was used as the excitation light. A solid quantum efficiency calculation program (manufactured by JASCO Corporation) was used to calculate the internal quantum yield. In addition, the maximum emission wavelength of the light emitted by each platinum complex was also measured. Table 3 shows the results of the emission quantum yield and the emission maximum wavelength. The emission characteristics of compound (1) in the amorphous state and the crystalline state are shown in FIGS. 3 and 4. FIG. 3 is measured at 298K and FIG. 4 is measured at 77K.

[X-ray crystal structure analysis]
The compound (1) of Example 1 and the compound (3) of Example 3 were subjected to single crystal X-ray crystallography using the imaging plate single crystal automatic X-ray structure analyzer PAPID-AUTO manufactured by Rigaku Co., Ltd. As X-rays, Mo-Kα rays (λ = 0.71075 Å) were used. As the compound (1) of Example 1, crystals crystallized by allowing the toluene solution to cool at room temperature were used. As the compound (3) of Example 3, crystals crystallized by allowing the chloroform solution to cool at room temperature were used. The crystal structure analysis of compound (1) of Example 1 was carried out at -173K. The molecular structure of the obtained compound (1) of Example 1 is shown in FIG. 5, the packing diagram of the obtained compound (1) in the crystal is shown in FIG. 6, and the molecular structure of the compound (3) of Example 3 is shown in FIG. FIG. 7 shows a packing diagram of the compound (3) of Example 3 in a crystal.

As shown in FIG. 5, it was confirmed that the compound (1) had a substantially planar structure except for the _{− (CH 2} ) _{12 − group.} Further, as shown in FIG. 6, it was confirmed why the compound (1) was arranged so as to face each other. Further, as shown in FIG. 7, it was confirmed that the compound (3) had a substantially planar structure.

[Effect of acid addition]
The UV spectrum and the emission spectrum were measured while adding methanesulfonic acid to ^{the acetonitrile solution (concentration 2.0 × 10 4} mol / l) of the compound (1) of Example 1. The obtained UV spectrum is shown in FIG. 9, and the emission spectrum is shown in FIG. An image of a solution of compound (1) to which methanesulfonic acid has been added is shown in FIG. In FIGS. 9-11, the numerical value is the equivalent of compound (1): methanesulfonic acid.

As shown in FIG. 9, it was confirmed that the absorbance slightly decreased with the addition of methanesulfonic acid. Further, as shown in FIG. 10, it was confirmed that the emission intensity gradually decreased with the addition of methanesulfonic acid. Further, as shown in FIG. 11, it was confirmed that the emission intensity became weaker with the addition of methanesulfonic acid. As described above, the compound of the present invention can regulate the light emission by the acid (proton).

Since the platinum complex of the present invention exhibits high luminous efficiency even in a solution state, it is possible to obtain practical emission intensity. It is also useful because platinum is used instead of iridium, which has a small reserve. Therefore, the light emitting material of the present invention is useful as a material for an organic light emitting device or the like, which is a next-generation technology.

Claims (3)

A platinum complex represented by the formula (I) or the formula (III).

[In the above formula,
n1 is an integer of 8 to 20 and
R ¹ is an alkyl group having 4 to 24 carbon atoms.
R ¹¹ and R ¹³ are independently hydrogen atom, halogen atom, alkyl group having 1 to 16 carbon atoms, alkoxy group having 2 to 16 carbon atoms, alkynyl group having 2 to 16 carbon atoms, cycloalkyl group, and carbon. It is selected from the number 1 to 16 alkoxy group, amino group, alkylamino group, hydroxy group, carboxyl group, alkoxycarbonyl group, phenyl group, phenoxy group, nitrile group, nitro group or thiol group. ] The platinum complex according to claim 1 , which is represented by the following formula (1), formula (3) or formula (4).

A luminescent material containing the platinum complex according to claim 1 or 2.

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