JP7270909B2 - Bisphosphine oxide rare earth complex and optical functional material - Google Patents

Description

The present invention relates to a bisphosphine oxide rare earth complex and an optical functional material.

The level of the 4f orbital of rare earth ions is usually not degenerate due to the existence of a crystal field or the like. When light corresponding to the energy difference between the levels is irradiated, light emission occurs due to electronic transition between the levels of the 4f orbital, and a sharp emission spectrum is obtained. The emission of rare earth ions based on such ff transition has high color purity and is beautiful, so it is attracting attention as a material for displays and optical devices. Rare-earth complexes, in which organic ligands are attached to rare-earth ions, have the characteristic that their optical functions can be freely controlled by changing the coordination structure and the combination of ligands.

Circularly polarized light emission (CPL) is generated by incorporating optically active ligands into rare earth complexes. Optical functional materials exhibiting circularly polarized luminescence can impart right-handed circularly polarized light and left-handed circularly polarized light as security information to normal visible light, and are therefore attracting attention as raw materials for security markers and polarized inks.

The term “circularly polarized luminescence” refers to the property that, for example, in a compound that emits fluorescence or phosphorescence when irradiated with ultraviolet rays, the intensities of left and right circularly polarized light of the fluorescence or phosphorescence emitted by the compound are different. Circular polarization can be indicated by a g value (anisotropy factor). For example, when the CPL spectrum is observed and the g _CPL value is calculated from the CPL spectrum by the following formula, the light is emitted such that g≠0.
g-value=2ΔI/I=2( _IL - _IR )/( _IL + _IR )
(In the formula, _IL represents the intensity of left-handed circularly polarized luminescence, and _IR represents the intensity of right-handed circularly polarized luminescence.)
Circular dichroism spectrum (CD spectrum) shows that clockwise and counterclockwise circularly polarized light can be selectively absorbed, and the g value is calculated from the following formula.
g value = 2Δε/ε = 2(ε _L - ε _R )/(ε _L + ε _R )
(In the formula, _εL is the absorption coefficient for left-handed circularly polarized light, and _IR is the absorption coefficient for right-handed circularly polarized light.)

Rare earth complexes having a binaphthyl structure, such as BINAPO, have been proposed as compounds exhibiting circularly polarized luminescence (Patent Documents 1 and 2). This rare earth complex exhibits circular polarization due to the asymmetric ligand field derived from the diasteremeric structure of the binaphthyl ligand.

Japanese Patent Application Laid-Open No. 2003-327590 JP 2005-097240 A

Although various rare earth complexes have been developed so far, only a small number of them have high emission intensity and circularly polarized light emission.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel rare earth complex. Another object of the present invention is to provide a rare earth complex having high emission intensity and circularly polarized light emission.

As a result of intensive research in view of the above-mentioned circumstances, the present inventors have found that a bisphosphine oxide rare earth complex with a specific structure has extremely high luminous intensity and circularly polarized light luminescence, and have completed the present invention. rice field.

That is, the first invention to be provided by the present invention is a bisphosphine oxide rare earth complex represented by the following general formula (1), in which a bisphosphine oxide ligand and an acetylacetone ligand are coordinated to a rare earth ion: is.

（式中、Ｒ^１～Ｒ^４は、置換されていてもよい直鎖状若しくは分岐状の炭素数１～１０のアルキル基、置換されていてもよいシクロアルキル基、置換されていてもよいアダマンチル基又は置換されていてもよいフェニル基を示し、Ｒ^１～Ｒ^４は、それぞれが同一の基であっても異なる基であってもよい。Ｒ^５は一価の置換基を示し、ｎは０～４の整数を示す。ｍ１は１～２の整数を示し、ｍ１が２の場合、２つのビスホスフィンオキシド配位子は、それぞれが同一であっても異なっていてもよい。
Ａ^１～Ａ^３は、水素原子、重水素原子、ハロゲン原子、水酸基、ニトロ基、アミノ基、スルホニル基、シアノ基、シリル基、ホスホン酸基、ジアゾ基、メルカプト基、炭素数１～２０のアルキル基、炭素数１～２０のハロゲン化アルキル基、炭素数１～２０のアルコキシ基、炭素数１～２０のアルコキシカルボニル基、ニトロ基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、置換されていてもよいジアリールホスフィノ基、置換されていてもよいジヘテロアリールホスフィノ基、炭素数１～２０のジアルキルホスフィノ基、炭素数１～２０のアルキルアリールホスフィノ基又は炭素数１～２０のアルキルヘテロアリールホスフィノ基を示す。Ａ^１～Ａ^３は、それぞれが同一の基であっても異なる基であってもよく、Ａ^１とＡ^３又はＡ^２とＡ^３はお互いに結合して環構造を形成していてもよい。ｍ２は２～４の整数を示し、２～４つのアセチルアセトン配位子は、それぞれが同一であっても異なっていてもよい。
Ｌｎは三価の希土類イオンを示す。）

(wherein R ¹ to R ⁴ are optionally substituted linear or branched alkyl groups having 1 to 10 carbon atoms, optionally substituted cycloalkyl groups, optionally substituted adamantyl or an optionally substituted phenyl group, R ¹ to R ⁴ may be the same group or different groups, R ⁵ is a monovalent substituent, and n is represents an integer of 0 to 4. m1 represents an integer of 1 to 2, and when m1 is 2, the two bisphosphine oxide ligands may be the same or different.
A ¹ to A ³ are hydrogen atom, deuterium atom, halogen atom, hydroxyl group, nitro group, amino group, sulfonyl group, cyano group, silyl group, phosphonic acid group, diazo group, mercapto group, C 1-20 alkyl group, halogenated alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkoxycarbonyl group having 1 to 20 carbon atoms, nitro group, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted diarylphosphino group, optionally substituted diheteroarylphosphino group, dialkylphosphino group having 1 to 20 carbon atoms, alkylarylphosphino group having 1 to 20 carbon atoms group or an alkylheteroarylphosphino group having 1 to 20 carbon atoms. A ¹ to A ³ may be the same group or different groups, and A ¹ and A ³ or A ² and A ³ may be bonded to each other to form a ring structure. . m2 represents an integer of 2 to 4, and the 2 to 4 acetylacetone ligands may be the same or different.
Ln represents a trivalent rare earth ion. )

A second invention to be provided by the present invention is an optically active substance of the bisphosphine oxide rare earth complex represented by the general formula (1).
A third invention to be provided by the present invention is an optical functional material containing an optically active substance of the bisphosphine oxide rare earth complex represented by the general formula (1) of the second invention.

According to the present invention, a novel rare earth complex can be provided. Furthermore, it is possible to provide a rare earth complex having high emission intensity and circularly polarized light emission.

2 is an excitation spectrum diagram of a solution of the bisphosphine oxide rare earth complex obtained in Example 1. FIG. 1 is an emission spectrum diagram of a solution of a bisphosphine oxide rare earth complex obtained in Example 1. FIG. 2 is an excitation spectrum diagram of the bisphosphine oxide rare earth complex powder obtained in Example 1. FIG. 2 is an emission spectrum diagram of the bisphosphine oxide rare earth complex powder obtained in Example 1. FIG. FIG. 2 is a CD spectrum diagram of the bisphosphine oxide rare earth complexes obtained in Examples 1 and 2. FIG. 2 is a CPL spectrum diagram of the bisphosphine oxide rare earth complexes obtained in Examples 1 and 2. FIG.

The present invention will be described below based on preferred embodiments.
The bisphosphine oxide rare earth complex according to the present invention is represented by the general formula (1). That is, it is a rare earth complex containing a bisphosphine oxide ligand site and an acetylacetone ligand site via a rare earth ion.

In the bisphosphine oxide rare earth complex of the present invention represented by the general formula (1), R ¹ , R ² , R ³ and R ⁴ in the formula relating to the bisphosphine oxide ligand moiety may be substituted. It represents a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted cycloalkyl group, an optionally substituted adamantyl group or an optionally substituted phenyl group. In addition, R ¹ to R ⁴ may each be the same group or different groups.

Linear or branched C1-C10 alkyl groups for R ¹ to R ⁴ include, for example, methyl group, ethyl group, isopropyl group, n-propyl group, isobutyl group, n-butyl group, sec-butyl group, tert-butyl group, isoheptyl group, n-heptyl group, isohexyl group, n-hexyl group, 1,1,3,3-tetramethylbutyl group (tert-octyl group) and the like.

The cycloalkyl group for R ¹ to R ⁴ preferably has 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms. Such cycloalkyl groups include cyclopentyl and cyclohexyl groups.

When R ¹ to R ⁴ are a substituted cycloalkyl group, a substituted adamantyl group or a substituted phenyl group, examples of the substituent include an alkyl group, a nitro group, an amino group, a hydroxyl group, An alkoxy group, a fluoro group, a chloro group, a bromo group, an iodo group and the like are included. When R ¹ to R ⁴ are substituted alkyl groups, the substituents include nitro, amino, hydroxyl, fluoro, chloro, bromo and iodo groups. If the substituent has carbon atoms, it preferably has the stated number of carbon atoms, including that carbon atom. When R ¹ to R ⁴ are alkyl groups having substituents, the substituents include trifluoromethyl group and the like.

R ⁵ associated with the bisphosphine oxide ligand moiety in the general formula (1) represents a monovalent substituent. R ⁵ is not particularly limited as long as it is a monovalent substituent, and examples thereof include linear or branched alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups, nitro groups, amino groups, hydroxyl group, alkoxy group, fluoro group, chloro group, bromo group, iodo group, silyl group and the like. n in the formula (1) represents an integer of 0-4.

A ¹ to A ³ related to the acetylacetone ligand moiety in the general formula (1) are a hydrogen atom, a deuterium atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, and a phosphonic group. acid group, diazo group, mercapto group, alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, 1 to 20 carbon atoms , preferably an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, preferably an alkoxycarbonyl group having 1 to 10 carbon atoms, a nitro group, an optionally substituted aryl group, an optionally substituted heteroaryl optionally substituted diarylphosphino group, optionally substituted diheteroarylphosphino group, dialkylphosphino group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, 1 to 20 carbon atoms , preferably an alkylarylphosphino group having 1 to 10 carbon atoms or an alkylheteroarylphosphino group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms.

Examples of the aryl group for A ¹ to A ³ include phenyl group, naphthyl group and anthryl group. The same applies to the aryl groups in the diarylphosphino groups and alkylarylphosphino groups for A ¹ to A ³ .

Examples of heteroaryl groups for A ¹ to A ³ include pyridyl group, thienyl group, furyl group, pyrazolyl group and imidazolyl group. The same applies to the heteroaryl groups in the diheteroarylphosphino groups and alkylheteroarylphosphino groups for A ¹ to A ³ .

Examples of substituents with which the aryl group of A ¹ to A ³ can be substituted include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, and a Examples thereof include alkoxy groups having 1 to 10 carbon atoms, alkoxycarbonyl groups having 1 to 10 carbon atoms, nitro groups, phenyl groups and naphthyl groups.

A ¹ to A ³ may each be the same group or different groups. A ¹ and A ² are preferably C 1-10 perfluoroalkyl groups, particularly preferably trifluoromethyl groups. Also, ^A3 is preferably a hydrogen atom or a deuterium atom.

Also, A ¹ and A ³ or A ² and A ³ may be bonded to each other to form a ring structure. When forming the ring structure, the acetylacetone ligand moiety is preferably a moiety derived from a camphor derivative represented by the following general formula (a) or (b). In addition, general formula (a) and general formula (b) have a relationship of optical isomers.

（式中、Ｚ^１は、ハロゲン原子、水酸基、ニトロ基、アミノ基、スルホニル基、シアノ基、シリル基、ホスホン酸基、ジアゾ基、メルカプト基、炭素数１～２０、好ましくは炭素数１～１０のアルキル基、炭素数１～２０、好ましくは炭素数１～１０のハロゲン化アルキル基、炭素数１～２０、好ましくは炭素数１～１０のアルコキシ基、炭素数１～２０、好ましくは炭素数１～１０のアルコキシカルボニル基、ニトロ基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、置換されていてもよいジアリールホスフィノ基、置換されていてもよいジヘテロアリールホスフィノ基、炭素数１～２０、好ましくは炭素数１～１０のジアルキルホスフィノ基、炭素数１～２０、好ましくは炭素数１～１０のアルキルアリールホスフィノ基又は炭素数１～２０、好ましくは炭素数１～１０のアルキルヘテロアリールホスフィノ基を示す。Ｚ^２～Ｚ^３はそれぞれ独立に、水素原子、重水素原子、ハロゲン原子、炭素数１～２０、好ましくは炭素数１～１０のアルキル基、水酸基、ニトロ基、アミノ基、スルホニル基、シアノ基、シリル基、ホスホン酸基、ジアゾ基又はメルカプト基のいずれかを示す。式中の＊は炭素原子上の不斉中心を示す。）

(In the formula, Z ¹ is a halogen atom, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, and has 1 to 20 carbon atoms, preferably 1 to 20 carbon atoms. 10 alkyl group, halogenated alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, alkoxy group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, 1 to 20 carbon atoms, preferably carbon Number 1 to 10 alkoxycarbonyl group, nitro group, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted diarylphosphino group, optionally substituted dihetero an arylphosphino group, a dialkylphosphino group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, an alkylarylphosphino group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, or 1 to 20 carbon atoms, It preferably represents an alkylheteroarylphosphino group having 1 to 10 carbon atoms, and Z ² to Z ³ each independently represent a hydrogen atom, deuterium atom, halogen atom, or 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. is an alkyl group, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, or a mercapto group, where * indicates an asymmetric center on a carbon atom .)

The aryl group for Z ¹ includes, for example, a phenyl group, a naphthyl group, an anthryl group, and the like. The same applies to the diarylphosphino group and the aryl group in the alkylarylphosphino group for Z ¹ .

Examples of the heteroaryl group for Z ¹ include pyridyl group, thienyl group, furyl group, pyrazolyl group and imidazolyl group. The same applies to the diheteroarylphosphino group and the heteroaryl group in the alkylheteroarylphosphino group for Z ¹ .

Examples of substituents with which the aryl group of Z ¹ can be substituted include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, and a halogenated alkyl group having 1 to 10 carbon atoms. alkoxy group having 10 carbon atoms, alkoxycarbonyl group having 1 to 10 carbon atoms, nitro group, phenyl group, naphthyl group and the like.

In the present invention, Z ¹ is preferably a C 1-10 perfluoroalkyl group, particularly preferably a trifluoromethyl group.

In addition, Ln in the general formula (1) represents a trivalent rare earth ion, such as Eu(III) ion, Tb(III) ion, Sm(III) ion, Yb(III) ion, Nd (III) ions, Er(III) ions, Dy(III) ions, and Gd(III) ions, among which Eu(III) ions and Tb(III) ions are preferred from the viewpoint of high emission intensity. , especially the Eu(III) ion.

m1 in the general formula (1) represents the coordination number of the bisphosphine oxide ligand to the trivalent rare earth ion represented by Ln, and m2 represents the acetylacetone coordination to the trivalent rare earth ion represented by Ln. Indicates the coordination number of the ligand. m1 represents an integer of 1 to 2, preferably 1; m2 represents an integer of 2 to 4, preferably 3; When m1 is 2, the two bisphosphine oxide ligands coordinated to the trivalent rare earth ion represented by Ln may be the same or different. The 2 to 4 acetylacetone ligands coordinated to the trivalent rare earth ion represented by Ln may be the same or different.

In the present invention, the bisphosphine oxide rare earth complex represented by the general formula (1) is preferably an optically active substance from the viewpoint of use as an optical functional material exhibiting circularly polarized luminescence. As the optically active substance, bisphosphine oxide rare earth complexes represented by the following general formulas (2) and (3) are used from the viewpoint of becoming rare earth complexes having high emission intensity and circularly polarized light emission properties. preferable.

In the analysis of the CPL spectrum, for example, the optically active form of the bisphosphine oxide rare earth complex represented by the following general formula (2) has a CPL spectrum in which the (R,R) form and the (S,S) form are inverted. Observed.

（式中のＲ^１～Ｒ^２、Ｒ^５、ｎ、Ａ^１～Ａ^３、Ｌｎ、ｍ１及びｍ２は前記一般式（１）と同義。但し、Ｒ^１とＲ^２は同一の基ではない。＊はリン原子上の不斉中心を示す。）

(In the formula, R ¹ to R ² , R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 have the same meanings as in general formula (1) above. However, R ¹ and R ² are not the same group. * indicates an asymmetric center on the phosphorus atom.)

（式中のＲ^１、Ｒ^３～Ｒ^４、Ｒ^５、ｎ、Ａ^１～Ａ^３、Ｌｎ、ｍ１及びｍ２は前記一般式（１）と同義。但し、Ｒ^３とＲ^４は同一の基ではない。＊はリン原子上の不斉中心を示す。）

(In the formula, R ¹ , R ³ to R ⁴ , R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 have the same meanings as in the general formula (1), provided that R ³ and R ⁴ are the same group. not. * indicates an asymmetric center on the phosphorus atom.)

The compound related to the optically active form of the bisphosphine oxide rare earth complex represented by the general formula (2) includes R ¹ , R ² , R ⁵ , n, and A ¹ to A ³ in the general formula (2). , Ln, m1 and m2 correspond to R ¹ , R ² , R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 in the formula of the bisphosphine oxide rare earth complex of general formula (1), respectively. and R ¹ =R ³ and R ² =R ⁴ .

R ¹ and R ² in the general formula (2) are preferably groups of any combination of the following (i) to (v) when used as an optically functional material.
(i) A combination of a tert-butyl group and a methyl group for R ¹ and R ² .
(ii) a combination of adamantyl and methyl groups for ^R1 and ^R2 ;
(iii) R ¹ and R ² are a combination of 1,1,3,3-tetramethylbutyl group and methyl group.
(iv) A combination of isopropyl and methyl groups for ^R1 and ^R2 .
(v) A combination of a 1-methylcyclohexyl group and a methyl group for ^R1 and ^R2 .
In the present invention, R ¹ and R ² in formula (2) are preferably combinations of (i) to (iii) above.

The compound related to the optically active form of the bisphosphine oxide rare earth complex represented by the general formula (3) includes R ¹ , R ³ to R ⁵ , n, and A ¹ to A ³ in the general formula (3). , Ln, m1 and m2 respectively correspond to R ¹ , R ³ to R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 in the formula of the bisphosphine oxide rare earth complex of general formula (1). , and is a compound having a relationship of R ¹ =R ² .

R ¹ , R ³ and R ⁴ in the general formula (3) are preferably any combination of groups (1) to (12) below when used as an optical functional material.
(1) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(2) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group (generally sometimes referred to as a "tert-octyl group") and a methyl group; .
(3) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(4) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group.
(5) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(6) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group and a methyl group.
(7) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(8) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group.
(9) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(10) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group and a methyl group.
(11) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(12) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group.

The bisphosphine oxide rare earth complex represented by the general formula (1) is obtained by the following general formula (5) by oxidizing the bisphosphine compound represented by the following general formula (4) according to the following reaction scheme (1). After obtaining the represented bisphosphine oxide compound, it can be produced by reacting it with a rare earth compound represented by the following general formula (6).

（式中のＲ^１～Ｒ^５、ｎ、Ａ^１～Ａ^３、Ｌｎ、ｍ１及びｍ２は前記一般式（１）と同義。）

(R ¹ to R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 in the formula have the same meanings as in general formula (1) above.)

The bisphosphine oxide compound represented by the general formula (5) can be obtained by oxidizing the bisphosphine compound represented by the general formula (4) with an oxidizing agent such as hydrogen peroxide.
The bisphosphine compound represented by the general formula (4) is a known compound and can be produced by a known production method (for example, JP-A-2007-56007, JP-A-2011-219413, JP-A-2011-219413, JP 2019-31460, WO2019/12918, WO2019/69828, Journal of Organic Chemistry Vol.77, 4184-4188 (2012), etc.).

Then, the bisphosphine oxide compound represented by the general formula (5) and the rare earth compound represented by the general formula (6) are stirred at -50 to 80°C, preferably 0 to 40°C for 1 to 24 hours. The bisphosphine oxide rare earth complex represented by the general formula (1) can be obtained by reacting the above.
Rare earth compounds represented by the general formula (6), for example, JP-A-2004-345989, JP-A-2005-82529, JP-A-2013-121921, JP-A-2016-166140, etc. It can be produced by the method described.
In the present invention, the rare earth compound represented by the general formula (6) is particularly preferably tris(hexafluoroacetylacetonato)europium (Eu(hfa) ₃ (H ₂ O) ₂ ).

When producing an optically active form of the bisphosphine oxide rare earth complex represented by the general formula (2) or (3), the bisphosphine compound represented by the general formula (4) is used. It is sufficient to use an optically active substance that The optically active form of the bisphosphine compound represented by the general formula (4) can be produced by a known production method (e.g., JP-A-2007-56007, JP-A-2011-219413 Publication, JP 2019-31460, WO2019/12918, WO2019/69828, Journal of Organic Chemistry Vol.77, 4184-4188 (2012), etc.). Further, the optically active form of the bisphosphine compound represented by the general formula (4) is commercially available from Nippon Kagaku Kogyo.

When the bisphosphine oxide rare earth complex of the present invention is used as an optical functional material, the bisphosphine oxide rare earth complex may be used directly, or the bisphosphine oxide rare earth complex may be contained in a transparent solid carrier such as a transparent polymer or transparent glass. good too. Alternatively, the bisphosphine oxide rare earth complex can be dissolved in an organic solvent to form a paint.

Examples of optical functional materials include circularly polarizing filters, security inks, security sensors, bio-related labeling agents (immunoassays), and circularly polarized light sources.

Further, the bisphosphine oxide rare earth complex represented by the general formula (2) includes various optical isomers of (R,R), (R,S), and (S,S), and the general formula (3). The bisphosphine oxide rare earth complex represented by has optical isomers (R) and (S), but when the bisphosphine oxide rare earth complex of the present invention is used as an optical functional material, these optical isomers It may be a mixture of bodies.

As the transparent polymer containing the bisphosphine oxide rare earth complex according to the present invention, those known in the art can be used. , polyethylene, polypropylene, polybutene and other polyolefins, fluorine-containing polyolefins, polyvinyl ether, fluorine-containing polyvinyl ether, polyvinyl acetate, polyvinyl chloride, and their copolymers, cellulose, polyacetal, polyester, polycarbonate, epoxy resin, polyamide resin , polyimide resin, polyurethane, Nafion, petroleum resin, rosin, silicone resin, etc., preferably polymethyl methacrylate, fluorine-containing polymethacrylate, polyacrylate, fluorine-containing polyacrylate, polystyrene, polyolefin, polyvinyl ether, and their co- One or more of polymers, epoxy resins, etc. can be used.

The method of blending and molding a polymer containing a bisphosphine oxide rare earth complex is not particularly limited, but injection molding, blow molding, compression molding, extrusion molding, reaction molding, hollow molding, thermoforming, FRP molding, etc. is mentioned.

A coating film containing a bisphosphine oxide rare earth complex may be formed on the surface of a carrier by conventionally known methods such as brush coating, dip coating, spin coating, plate coating, and spinner coating. A coating method, a bead coating method, a gravure printing method, a screen printing method, an offset printing method, and a letterpress printing method can be used.

Moreover, the bisphosphine oxide rare earth complex of the present invention can be used in combination with an organic dye for the purpose of changing the emission color.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

<Bisphosphine compound>
(R,R) form of 2,3-bis(tert-butylmethylphosphino)quinoxaline represented by the following general formula (4a) (abbreviation: (R,R)-QuinoxP ^* , manufactured by Nippon Kagaku Kogyo Co., Ltd.); , 2,3-bis(tert-butylmethylphosphino)quinoxaline (S,S) form (abbreviation: (S,S)-QuinoxP ^* , manufactured by Nippon Kagaku Kogyo Co., Ltd.) was used.

（式中、Ｒ^１はメチル基、Ｒ^２はｔｅｒｔ－ブチル基を示す。）

(In the formula, R ¹ represents a methyl group and R ² represents a tert-butyl group.)

＜Ｒ，Ｒ－ＱｕｉｎｏｘＰ^＊Ｏの合成＞
（Ｒ，Ｒ）－ＱｕｉｎｏｘＰ^＊（９８．３ｍｇ、０．２９ｍｍｏｌ）をジクロロメタン（２ｍＬ）に溶解させた。その溶液を０℃に冷却し、Ｈ_２Ｏ_２３０％ａｑ．（２ｍＬ）を滴下し、４時間撹拌した。反応液をジクロロメタンと飽和食塩水で３度抽出し、有機層をＭｇＳＯ_４で脱水し、溶媒を除去することで白色粉体（Ｒ，Ｒ－ＱｕｉｎｏｘＰ^＊Ｏ）を得た。
（Ｒ，Ｒ－ＱｕｉｎｏｘＰ^＊Ｏの同定データ）
^１Ｈ ＮＭＲ（４００ＭＨｚ，ＣＤＣｌ_３／ＴＭＳ） δ／ｐｐｍ＝８．１２（ｄｄ，２Ｈ，Ｊ＝３．４Ｈｚ，６．４Ｈｚ），７．９１（ｄｄ，２Ｈ，Ｊ＝３．２Ｈｚ，６．４Ｈｚ），２．１２（ｄ，６Ｈ，Ｊ＝１２．８Ｈｚ），１．４４（ｄ，１８Ｈ，Ｊ＝１４．６Ｈｚ） [Example 1]

<Synthesis of R,R-QuinoxP ^* O>
(R,R)-QuinoxP ^* (98.3 mg, 0.29 mmol) was dissolved in dichloromethane (2 mL). The solution is cooled to 0° C. and H ₂ O ₂ 30% aq. (2 mL) was added dropwise and stirred for 4 hours. The reaction solution was extracted three times with dichloromethane and saturated brine, the organic layer was dried over MgSO ₄ and the solvent was removed to obtain a white powder (R,R-QuinoxP ^* O).
(Identification data of R,R-QuinoxP ^* O)
^<1> H NMR (400 MHz, _CDCl3 /TMS) [delta]/ppm = 8.12 (dd, 2H, J = 3.4 Hz, 6.4 Hz), 7.91 (dd, 2H, J = 3.2 Hz, 6.4 Hz). 4Hz), 2.12 (d, 6H, J = 12.8Hz), 1.44 (d, 18H, J = 14.6Hz)

<Synthesis of Eu(hfa) ₃ (R,R-QuinoxP ^* O)>
R,R-QuinoxP ^* O (66.7 mg, 0.18 mmol) was dissolved in dichloromethane (5 ml). Eu(hfa) ₃ (H ₂ O) ₂ (193.4 mg, 0.24 mmol) was added to the solution and stirred for 2 hours. The reaction solution was filtered, and after removing the solvent of the filtrate, recrystallization was performed with methanol to obtain colorless and transparent dendrites (Eu(hfa) ₃ (R,R-QuinoxP ^* O)).
(Identification data of (Eu(hfa) ₃ (R,R-QuinoxP ^* O))
ESI-Mass (m/z): [M-hfa] ⁺ calcd. _{for C28H30EuF12N2O6P2} , _{933.06 ;} found _{, 933.09}
Elemental analysis (%): calcd. for _{C33H31EuF18N2O8P2} , C _{34.78 ,} H _2.74 , N 2.46 _; found, C 34.50 _, H 2.50, N 2.33
FT-IR (ATR): 1653 (st, C=O), 1252 (st, CF), 1139 (st, P=O) cm ⁻¹

（Ｒ，Ｒ）－ＱｕｉｎｏｘＰ^＊に代えて（Ｓ，Ｓ）－ＱｕｉｎｏｘＰ^＊を用いた以外は実施例１と同様にして、無色透明な樹状結晶（Ｅｕ（ｈｆａ）_３（Ｓ，Ｓ－ＱｕｉｎｏｘＰ^＊Ｏ）を得た。
（（Ｅｕ（ｈｆａ）_３（Ｓ，Ｓ－ＱｕｉｎｏｘＰ^＊Ｏ）の同定データ）
ＥＳＩ－Ｍａｓｓ（ｍ／ｚ）：［Ｍ－ｈｆａ］^＋ ｃａｌｃｄ． ｆｏｒ Ｃ_２８Ｈ_３０ＥｕＦ_１２Ｎ_２Ｏ_６Ｐ_２，９３３．０６； ｆｏｕｎｄ，９３３．１０
Ｅｌｅｍｅｎｔａｌ ａｎａｌｙｓｉｓ（％）：ｃａｌｃｄ． ｆｏｒ Ｃ_３３Ｈ_３１ＥｕＦ_１８Ｎ_２Ｏ_８Ｐ_２，Ｃ ３４．７８，Ｈ ２．７４，Ｎ ２．４６； ｆｏｕｎｄ，Ｃ ３４．３６，Ｈ ２．５３，Ｎ ２．２９ [Example 2]

Colorless and transparent dendrites (Eu(hfa) ₃ (S,S-QuinoxP ⁾ were prepared in the same manner as in Example 1 except that (S,S)-QuinoxP ^* was used instead of (R,R)-QuinoxP*. ^* O) was obtained.
(Identification data of (Eu(hfa) ₃ (S, S-QuinoxP ^* O))
ESI-Mass (m/z): [M-hfa] ⁺ calcd. _{for C28H30EuF12N2O6P2} , _{933.06 ;} found _{, 933.10}
Elemental analysis (%): calcd. for _{C33H31EuF18N2O8P2} , C _{34.78 ,} H _2.74 , N 2.46 _; found, C 34.36 _, H 2.53, N 2.29

(Measurement of emission quantum yield)
An excitation spectrum (FIG. 1) and an emission spectrum (FIG. 2) in a solution of the bisphosphine oxide rare earth complex (Eu(hfa) ₃ (R,R-QuinoxP ^* O)) obtained in Example 1 were measured. A sample prepared by dissolving 11.4 mg of Eu(hfa) ₃ (R,R-QuinoxP ^* O) in 10 mL of dichloromethane for spectroscopic analysis was used for the measurement.

(Calculation of luminescence quantum yield φ _Ln , radiation rate constant k _r , non-radiation rate constant k _nr )
The luminescence quantum yield φ _Ln , the radiation rate constant k _r , and the non-radiation rate constant k _nr were calculated based on equations (1) to (3). Table 1 shows the results.
_φLn = _kr /( _kr + _knr )= _τobs / _τrad (1)
1/ _τrad = _AMD, ⁰ⁿ³ ( _Itot / _IMD ) (2)
k _r =1/τ _rad (3)
τ _obs : Observed luminescence lifetime τ _rad : Ideal luminescence lifetime without deactivation process A _MD,0 : Constant 14.65 s ⁻¹
n: refractive index of solvent I _tot /I _MD : area of magnetic dipole transition/total area of emission spectrum (measurement of optical properties)

Further, the excitation spectrum (FIG. 3) and emission spectrum (FIG. 4) of the bisphosphine oxide rare earth complex (Eu(hfa) ₃ (R,R-QuinoxP ^* O)) obtained in Example 1 were measured.
Table 2 shows the calculated emission quantum yield φ _Ln , radiation rate constant k _r , and non-radiation rate constant k _nr .

(Measurement of CD spectrum)
In order to determine the circularly polarized luminescence properties of the bisphosphine oxide rare earth complexes obtained in Examples 1 and 2, a dichloromethane solution (1×10 ⁻⁴ M) of the bisphosphine oxide rare earth complex was prepared and its CD spectrum was measured. . The results are shown in FIG.

(Measurement of circularly polarized light emission spectrum (CPL spectrum))
In order to examine the circularly polarized light of the bisphosphine oxide rare earth complexes obtained in Examples 1 and 2, circularly polarized light emission spectra (CPL spectra) were measured. A bisphosphine oxide rare earth complex in dichloromethane solution (1×10 ⁻³ M) was prepared and the circularly polarized light emission spectrum was measured under the following measurement conditions. The results are shown in FIG.
Measuring device: CPL-200 (JASCO)
Excitation side: excitation wavelength: 360 nm, slit width: 3000 μm
Detection side: Sensitivity: Standard, Data acquisition interval: 0.2 nm, Scanning mode: Continuous, Scanning speed: 10 nm/min, Response: 1 sec, Slit width: 200 µm, Integration: 5 times

As shown in FIGS. 5 and 6, the (R,R) and (S,S) isomers had inverted CD and CPL spectra. Also, the g _CPL value was calculated from the CPL spectrum by the following formula. Table 3 shows the results. In addition, the g _CPL value was described as an absolute value. In Example 1, the values are at an emission wavelength of 588.4 nm, and in Example 2, the values are at an emission wavelength of 588.6 nm.
g-value=2ΔI/I=2( _IL - _IR )/( _IL + _IR )
(In the formula, _IL represents the intensity of left-handed circularly polarized luminescence, and _IR represents the intensity of right-handed circularly polarized luminescence.)

Table 3 confirms that the g _CPL is 2 to 2.5 times higher than the literature value of Eu(hfa) ₃ (R-BINAPO) (0.03) (Inorg. Chem. 2009, 48, 11242). rice field.

Claims (7)

A bisphosphine oxide rare earth complex represented by the following general formula (1), in which a bisphosphine oxide ligand and an acetylacetone ligand are coordinated to a rare earth ion.

(wherein R ¹ to R ⁴ are optionally substituted linear or branched alkyl groups having 1 to 10 carbon atoms, optionally substituted cycloalkyl groups, optionally substituted adamantyl or an optionally substituted phenyl group, R ¹ to R ⁴ may be the same group or different groups, R ⁵ is linear or branched, and a monovalent substituent selected from an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group, a nitro group, an amino group, a hydroxyl group, an alkoxy group, a fluoro group, a chloro group, a bromo group, an iodo group and a silyl group; , n represents an integer of 0 to 4. m1 represents an integer of 1 to 2, and when m1 is 2, the two bisphosphine oxide ligands may be the same or different.
A ¹ to A ³ are hydrogen atom, deuterium atom, halogen atom, hydroxyl group, nitro group, amino group, sulfonyl group, cyano group, silyl group, phosphonic acid group, diazo group, mercapto group, C 1-20 alkyl group, halogenated alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkoxycarbonyl group having 1 to 20 carbon atoms, nitro group, optionally substituted aryl group, optionally substituted heteroaryl group, optionally substituted diarylphosphino group, optionally substituted diheteroarylphosphino group, dialkylphosphino group having 1 to 20 carbon atoms, alkylarylphosphino group having 1 to 20 carbon atoms group or an alkylheteroarylphosphino group having 1 to 20 carbon atoms. A ¹ to A ³ may be the same group or different groups, and A ¹ and A ³ or A ² and A ³ may be bonded to each other to form a ring structure. . m2 represents an integer of 2 to 4, and the 2 to 4 acetylacetone ligands may be the same or different.
Ln represents a trivalent rare earth ion. ) An optically active form of the bisphosphine oxide rare earth complex represented by the general formula (1). 3. The optically active bisphosphine oxide rare earth complex according to claim 2, represented by the following general formula (2) or (3).

(R ¹ to R ² , R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 in general formula (2) have the same meanings as in general formula (1), provided that R ¹ and R ² are not the same group.
R ¹ , R ³ to R ⁴ , R ⁵ , n, A ¹ to A ³ , Ln, m1 and m2 in general formula (3) have the same meanings as in general formula (1). However, R ³ and R ⁴ are not the same group.
* in formulas (2) and (3) indicates an asymmetric center on the phosphorus atom. ) 4. The optically active bisphosphine oxide rare earth complex according to claim 3, wherein R ¹ and R ² in general formula (2) are any combination of groups (i) to (v) below.
(i) A combination of a tert-butyl group and a methyl group for R ¹ and R ² .
(ii) a combination of an adamantyl group and a methyl group for ^R1 and ^R2 ;
(iii) R ¹ and R ² are a combination of 1,1,3,3-tetramethylbutyl group and methyl group.
(iv) A combination of isopropyl and methyl groups for R ¹ and R ² .
(v) R ¹ and R ² are a combination of a 1-methylcyclohexyl group and a methyl group. The optically active form of the bisphosphine oxide rare earth complex according to claim 3, wherein R ¹ , R ³ and R ⁴ in the general formula (3) are any combination of groups (1) to (12) below. .
(1) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(2) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group and a methyl group.
(3) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(4) R ¹ is a tert-butyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group.
(5) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(6) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group and a methyl group.
(7) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(8) R ¹ is an adamantyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group.
(9) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of a tert-butyl group and a methyl group.
(10) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of a 1,1,3,3-tetramethylbutyl group and a methyl group.
(11) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of an adamantyl group and a methyl group.
(12) R ¹ is a 1,1,3,3-tetramethylbutyl group, and R ³ and R ⁴ are a combination of an isopropyl group and a methyl group. 4. The rare earth complex according to claim 3, wherein A ¹ and A ² in formulas (2) and (3) are perfluoroalkyl groups having 1 to 10 carbon atoms, and A ³ is a hydrogen atom. 3. An optically functional material comprising an optically active substance of the bisphosphine oxide rare earth complex represented by the general formula (1) according to claim 2.

Images