JP6230326B2 - Phosphor and use thereof - Google Patents

Description

  The present invention relates to a novel phosphor and use thereof.

  Compared to inorganic phosphors, organic phosphors can be manufactured at lower manufacturing costs, and because of their low specific gravity and good dispersibility in media, dye lasers, bioimaging, organic EL light-emitting dyes, solar cell light It is used in a wide range of fields such as wavelength conversion materials. However, it is known as a characteristic of organic phosphors that it causes a significant decrease in luminance due to concentration quenching under high concentration conditions. In order to avoid these problems, it is a common practice to use organic phosphors in a dilute state in which they are uniformly dispersed at a molecular level in a low molecular or high molecular host material or solvent.

  On the other hand, contrary to conventional organic phosphors, so-called aggregation-induced luminescent molecules have been found in which light emission increases significantly when aggregated, overcoming the problems of conventional organic phosphors, and in the medical field. It is expected to realize new applications of organic phosphors in the industrial field and the like (see Non-Patent Documents 1 and 2).

  By the way, there are many reports on substituted maleimides (see Patent Document 1, Non-Patent Documents 3 to 8), and some are known as organic phosphors (see Patent Document 1, Non-Patent Documents 3 and 4). A substituted maleimide conventionally used as an organic phosphor has a structure in which a benzene ring or a heterocyclic ring is directly bonded to the 2-position or 3-position. However, the maleimide organic phosphor does not exhibit aggregation-induced light emission.

Special table 2003-509441 gazette

Chem.Commun., 2009,4332-4353 Chem.Commun., 2010,46,9013-9015 Chem.Commun., 2003,404-405 J. Polym. Sci. Part A: Polym. Chem., 49, 3550-3558 (2011) J. Org. Chem., 35, 3138 (1970) J. Org. Chem., 40, 423 (1975) J. Heteocyclic Chem., 25, 1777 (1988) Chem. Heterocyclic Comp., 43, 844-845 (2007)

  There has never been an organic phosphor having a relatively simple structure, capable of controlling the emission color in the visible region, and exhibiting aggregation-induced luminescence.

  The aggregation-induced luminescent molecule described in Non-Patent Document 1 has an extremely limited structure in which a large number of aromatic rings are bonded to a propeller type, and the molecular design guidelines are insufficient, so that the aggregation-induced luminescent molecule according to the purpose Is difficult to synthesize.

  In addition, the aggregation-induced light-emitting molecule described in Non-Patent Document 2 cannot emit light due to its molecular structure being distorted by itself because the light-emitting portion of the dye molecule is extremely long. However, when the molecules are aggregated and stacked, the planarity increases and fluorescence is increased. Has a mechanism to dramatically increase. However, this technique cannot be applied to simple molecules with low molecular weight.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic phosphor having a relatively simple structure, capable of controlling a luminescent color in the visible region, and exhibiting aggregation-induced luminescence. Is to realize.

  In order to solve the above problems, according to one aspect of the present invention, there is provided a phosphor comprising an aminomaleimide represented by the following general formula (1).

(In general formula (1),
A represents a substituted or unsubstituted saturated alkyl group,
B represents a substituted or unsubstituted phenyl group. )
According to said structure, there exists an effect that it is possible to implement | achieve the organic fluorescent substance which can control luminescent color in a visible region with a comparatively simple structure, and shows aggregation-induced luminescent property.

  In one embodiment, A is a C3-C20 linear or branched substituted or unsubstituted saturated alkyl group.

  The aggregation-inducing luminescent material according to the present invention is characterized by containing the phosphor.

  The pH stimulus responsive material according to the present invention is characterized by containing the phosphor.

  The light wavelength conversion material according to the present invention is characterized by including the phosphor.

  As described above, the phosphor according to the present invention has a structure made of aminomaleimide represented by the general formula (1), so that the emission color can be controlled in the visible region with a relatively simple structure. In addition, an organic phosphor exhibiting aggregation-induced light emission can be realized.

¹ H-NMR spectrum of 2-anilino-Nn-hexylmaleimide obtained according to Example 1 of the present invention. It is a figure which shows the result of having measured the emission spectrum of the aminomaleimide powder obtained by Example 1 of this invention. In Example 5 of the present invention, 2-anilino-Nn- in a mixed solvent of THF and water in which the ratio of water to the total weight of the mixture is 70% by weight, 72% by weight, and 80% by weight, respectively. It is a figure which shows the result of having confirmed the increase in the emitted light intensity accompanying aggregation by irradiating a near-ultraviolet ray to hexyl maleimide. In Example 5 of the present invention, 2-anilino-Nn- in a mixed solvent of THF and water in which the ratio of water to the total weight of the mixture is 70% by weight, 72% by weight, and 80% by weight, respectively. It is a figure which shows the result of having excited hexyl maleimide at 335 nm and having measured the emission spectrum. It is a figure which shows the result of having irradiated the solid film of 2-anilino-N-hexyl maleimide of Example 1 of this invention with the black light blue lamp. (A) Maximum emission wavelength of the emission spectrum of the aminomaleimide powder, EVA film, PS film and PMMA film of Examples 1 to 3 of the present invention with an excitation wavelength of 400 nm. (B) Emission spectra of anilino-N-hexylmaleimide powder crystals, EVA film and PS film of Example 1. In Example 7 of this invention, it is a figure which shows the pH responsiveness of light emission of aminomaleimide, (A) shows the liquid mixture of 2-anilino-Nn-hexylmaleimide, THF, and water under near ultraviolet irradiation. It is a figure and (B) is a figure which shows the liquid mixture after 35% HCl aqueous solution addition.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this, and can be implemented in a mode in which various modifications are made within the described range. Moreover, all the academic literatures and patent literatures described in this specification are incorporated herein by reference. Unless otherwise specified in this specification, “A to B” indicating a numerical range means “A or more and B or less”.

(I) Phosphor according to the present invention As a result of intensive studies in view of the above problems, the present inventors have found that a substituted or unsubstituted saturated alkyl group is bonded to the N-position of maleimide, and 2-position or 3-position of maleimide. It was found that the aminomaleimide in which a substituted or unsubstituted phenyl group is bonded to the C atom of the compound does not emit light in a solution, and the emission is remarkably increased when the molecules are aggregated.

  As a result, it has been found that an organic phosphor having a relatively simple structure having a low molecular weight and capable of controlling the emission color in the visible region and exhibiting aggregation-induced light emission can be realized. The present invention has been completed.

  That is, the phosphor according to the present invention comprises an aminomaleimide represented by the following general formula (1). In this specification, the C atom adjacent to the N atom (N position) of the 5-membered ring forming maleimide is defined as the first position, and the C atom adjacent to the C atom is defined as the second position to form maleimide. Shall be numbered in order.

  Here, in the general formula (1), A represents a substituted or unsubstituted saturated alkyl group, and B represents a substituted or unsubstituted phenyl group.

  The saturated alkyl group of A may be a linear, branched or cyclic saturated alkyl group. Examples of linear saturated alkyl include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, etc. Is mentioned. Examples of branched saturated alkyls include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl, isododecyl, isotridecyl, isotetradecyl, isopentadecyl, isohexadecyl Examples include decyl, isoheptadecyl, isooctadecyl, isononadecyl, and isoicosyl. Examples of cyclic saturated alkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like.

  The number of carbon atoms of the saturated alkyl group is not particularly limited as long as it has the function of a phosphor, but usually 1 to 20 (especially 1 to 20 in the case of a straight chain, 3 to 20 in the case of a branched chain or a ring), more preferably Is 3-20, even more preferably 5-16, most preferably 6-10. When the saturated alkyl group is substituted, the carbon number of the saturated alkyl group indicates the total number of carbon atoms including the carbon number in the substituent.

  The saturated alkyl group may be substituted with one or more substituents, and when the saturated alkyl group has a substituent, usually 1 to 3, more preferably 1 or 2 substituents, particularly preferably Substituted with one substituent. The substituent may be bonded to any position of the alkyl group.

  The substituent of the saturated alkyl group is not particularly limited as long as it does not impair the function of the aminomaleimide phosphor of the present invention, and examples thereof include an alkyl group having 1 to 6 carbon atoms or a halogen atom. It is done. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group. The halogen atom may be any halogen atom selected from F, Cl, Br and I.

  The phenyl group of B may be substituted with one or more substituents, and when the saturated alkyl group has a substituent, usually 1 to 3, more preferably 1 or 2 substituents, particularly preferably Is substituted with one substituent. The substituent may be bonded at any position with respect to the amino group bonded to the C atom at the 2-position of maleimide.

  The substituent of the phenyl group is not particularly limited as long as it does not impair the action of the aminomaleimide of the present invention as a phosphor, and examples thereof include an alkyl group having 1 to 6 carbon atoms or a halogen atom. . Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group. The halogen atom may be any halogen atom selected from F, Cl, Br and I.

  Examples of preferred B phenyl groups include phenyl, (o-, m-, p-) methylphenyl, (o-, m-, p-) ethylphenyl, (o-, m-, p-) propylphenyl, (O-, m-, p-) butylphenyl, (o-, m-, p-) pentylphenyl, (o-, m-, p-) hexylphenyl and the like.

  For example, when B is a phenyl group and there is one substituent, the aminomaleimide of the present invention is represented by the following general formula (2)

R ¹ may be bonded to any of the para position, the meta position, and the ortho position with respect to the amino group bonded to the C atom at the 2-position of maleimide. When benzene is unsubstituted, R ¹ is hydrogen.

R ¹ is not particularly limited as long as it is an arbitrary substituent that does not impair the action of the aminomaleimide of the present invention as a phosphor, and examples thereof include an alkyl group having 1 to 6 carbon atoms or a halogen atom. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and an isobutyl group. The halogen atom may be any halogen atom selected from F, Cl, Br and I.

  Representative aminomaleimides constituting the phosphor according to the present invention include, for example, 2-anilino-Nn-pentylmaleimide, 2-anilino-Nn-hexylmaleimide, 2-anilino-Nn-heptyl. Maleimide, 2-anilino-Nn-octylmaleimide, 2-anilino-Nn-nonylmaleimide, 2-anilino-Nn-decylmaleimide, 2-anilino-Nn-undecylmaleimide, 2-anilino -Nn-dodecylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-pentylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-hexyl Maleimide, 2- (o-, m-, p-)-toluidino-Nn-heptylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-octylmaleimide 2- (o-, m-, p-)-toluidino-Nn-nonylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-decylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-undecylmaleimide, 2- (o-, m-, p-)-toluidino-Nn-dodecylmaleimide, 2- (o-, m-, p- ) -Methylbenzylaminopentylmaleimide, 2- (o-, m-, p-)-methylbenzylaminohexylmaleimide, 2- (o-, m-, p-)-methylbenzylaminoheptylmaleimide, 2- (o -, M-, p-)-methylbenzylaminooctylmaleimide, 2- (o-, m-, p-)-methylbenzylaminononylmaleimide, 2- (o-, m-, p-)-methylbenzylamino Decylmaleimide, 2- (o- m-, p-)-methylbenzylaminoundecylmaleimide, 2- (o-, m-, p-)-methylbenzylaminododecylmaleimide, 2- (o, m, p) -bromoanilino-Nn-pentyl Maleimide, 2- (o, m, p) -bromoanilino-Nn-hexylmaleimide, 2- (o, m, p) -bromoanilino-Nn-heptylmaleimide, 2- (o, m, p)- Bromoanilino-Nn-octylmaleimide, 2- (o, m, p) -bromoanilino-Nn-nonylmaleimide, 2- (o, m, p) -bromoanilino-Nn-decylmaleimide, 2- ( o, m, p) -bromoanilino-Nn-undecylmaleimide, 2- (o, m, p) -bromoanilino-Nn-dodecylmaleimide, and the like.

  In one embodiment, the present invention includes an aminomaleimide represented by the following general formula (3):

In general formula (3),
R ¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom,
n represents any of 0-2, 4, and 6-10.

  The phosphor according to the present invention does not emit light in a solution. Here, in this specification, the solution means a uniform mixture in a liquid state. That is, in a state where the phosphor according to the present invention is completely dissolved in a solvent, it does not emit light even when excited with near ultraviolet light. Note that near-ultraviolet light refers to light of 300 to 400 nm. The reason why the phosphor according to the present invention does not emit light in a molecularly dispersed solution is that the substituted or unsubstituted phenylamino group bonded to the 2nd or 3rd position of the maleimide molecule freely rotates in the solution. It is thought that this is because the light is not consumed by the rotational movement. Compared with the aminomaleimide molecule of the present invention, the conventional phosphor having a structure in which a benzene ring or a heterocycle is directly bonded to the 2-position or 3-position of the aminomaleimide molecule allows the benzene ring or heterocycle to rotate freely. It is thought that it does not quench in the solution because it is difficult to do.

  The phosphor according to the present invention is a phosphor having so-called aggregation-induced luminescence that does not emit light in a solution, but emits light significantly in a liquid state or a solid state where a molecular aggregation state occurs. When the phosphor according to the present invention is added to the solution with the non-solvent or poor solvent of the phosphor according to the present invention to precipitate and aggregate the phosphor according to the present invention, the phosphor emits light with near-ultraviolet excitation light. Confirmed to do. Further, as the proportion of the non-solvent or poor solvent added increases and the amount of aggregation increases, the emission intensity increases.

  In addition, the phosphor according to the present invention emits light in a solid state, the maximum emission wavelength is 400 nm to 650 nm, and the wavelength of excitation light is 250 nm to 500 nm.

  The reason why the phosphor according to the present invention remarkably increases the light emission in the aggregated (solid) state and does not cause a decrease in luminance due to concentration quenching under high concentration conditions is as follows: (i) C at the 2- or 3-position of maleimide The rotation of the substituted or unsubstituted phenylamino group bonded to the atom is suppressed, and the planarity of the benzene ring and the maleimide ring of the phenylamino group at the 2-position is increased; and (ii) the maleimide ring and the maleimide It is considered that π-stacking is suppressed by twisting with the N-substituent.

  As described above, the phosphor according to the present invention has a conventional maleimide phosphor by virtue of the free rotation of the substituted or unsubstituted phenylamino group bonded to the C atom at the 2-position or 3-position of maleimide and its suppression. No quenching in solution, and has the property that luminescence is significantly increased by aggregation. Therefore, it can be suitably used for a sensor using a difference in light emission behavior between a solution and an aggregated state.

  In addition, the phosphor according to the present invention is bonded to the substituted or unsubstituted phenylamino group (amine-side substituent) bonded to the C atom at the 2-position or 3-position of maleimide, and bonded to the N-position of maleimide. It has been found that light is emitted in different colors by changing the substituent of the saturated alkyl group (the substituent on the imide side). Therefore, in the phosphor according to the present invention, the emission wavelength can be finely adjusted by appropriately selecting the amine-side substituent and the imide-side substituent.

(II) Method for producing phosphor according to the present invention The method for producing the phosphor according to the present invention is not particularly limited, and a conventionally known method can be appropriately selected and used.

  As an example of the manufacturing method of the phosphor according to the present invention, the following general formula (4)

And dimethyl acetylenedicarboxylate represented by the following general formula (5)
R ³ NH ₂ (5)
A first step of reacting with a primary amine represented by the following general formula (6) obtained by the first step:

And a compound represented by the following general formula (7)
R ⁴ NH ₂ (7)
And a second step of obtaining an aminomaleimide represented by the following general formula (8) by reacting with a primary amine represented by formula (8).

Here, R ³ is the phenyl group of B described in the description of the general formula (1) of (I). R ⁴ is the saturated alkyl group of A described in the description of the general formula (1) of (I) above.

  According to the said manufacturing method, the group couple | bonded with N position of maleimide is the saturated alkyl group of A described in the description of general formula (1) of said (I), and N couple | bonded with C atom of 2-position of maleimide. An aminomaleimide in which the group bonded to the atom is a phenyl group of B can be obtained.

  In the above two-step method, in the first step, the compound represented by the general formula (4) is reacted with the primary amine represented by the general formula (5) to represent the compound represented by the general formula (6). To obtain the compound. Here, the molar ratio of the primary amine represented by the general formula (5) to the compound represented by the general formula (4) (number of moles of the primary amine represented by the general formula (5) / general formula (4 The number of moles of the compound represented by) is not particularly limited, but is preferably about 1 to 4.

  In addition, the solvent that can be used in the first step is not particularly limited as long as the compound represented by the general formula (4) and the primary amine represented by the general formula (5) react with each other. It may be used according to. As such a solvent, for example, DMAc, toluene, chlorobenzene and the like can be suitably used. Alternatively, no solvent may be used if the reaction mixture is in a liquid state during the reaction.

  The reaction temperature in the first step is not particularly limited, and is usually −20 to 150 ° C., may be 60 to 120 ° C. in one embodiment, and may be 0 to 40 ° C. in another embodiment. It can also be synthesized under reaction conditions. Also, the reaction time is not particularly limited, but is usually 30 minutes to 1 day, more preferably 1 to 10 hours.

  In the two-step method, the phosphor according to the present invention is produced by reacting the primary amine represented by the general formula (7) with the compound represented by the general formula (6) in the second step. can do. Here, the molar ratio of the primary amine represented by the general formula (7) to the compound represented by the general formula (6) (number of moles of the primary amine represented by the general formula (7) / general formula (6 ) Is preferably about 1-4.

  The solvent that can be used in the second step is not particularly limited as long as the compound represented by the general formula (6) and the primary amine represented by the general formula (7) react with each other. It may be used according to. As such a solvent, for example, DMAc, toluene, DMF and the like can be suitably used. Alternatively, no solvent may be used if the reaction mixture is in a liquid state during the reaction.

  The reaction temperature in the second step is not particularly limited, but is −20 to 150 ° C., may be 80 to 150 ° C. in one embodiment, and may be 0 to 40 ° C. in another embodiment. It can also be synthesized under reaction conditions. Also, the reaction time is not particularly limited, but is usually 30 minutes to 2 days, more preferably 4 to 24 hours.

  According to the method for producing a phosphor of the present invention, it has been found that the quantum yield of the obtained phosphor is significantly increased. For example, a conventional aminomaleimide organic phosphor has a quantum yield of 8% or less, but in the case of the phosphor of the present invention, the quantum yield is 10% or more, and in some cases 20% or 30% or more. Rate can be achieved.

(III) Utilization of phosphor according to the present invention As described above, the phosphor according to the present invention does not emit light in a solution, but the so-called aggregation induction in which light emission is remarkably increased in a liquid state or a solid state where a molecular aggregation state occurs. It is a phosphor having a light emitting property. Therefore, it can be used under high concentration conditions. In addition, the emission wavelength can be finely adjusted by appropriately selecting a substituent on the amine side and a substituent on the imide side. Therefore, the phosphor according to the present invention can be suitably used in a wide range of fields such as dye lasers, bioimaging, and organic EL light-emitting elements.

  In addition, the phosphor according to the present invention is a solution that is not found in conventional maleimide phosphors by free rotation of a substituted or unsubstituted phenylamino group bonded to the C atom at the 2-position or 3-position of maleimide and its suppression. It has the characteristics that it is quenched and emits light significantly by aggregation. Therefore, it can be suitably used for a sensor using a difference in light emission behavior between a solution and an aggregated state.

  Therefore, the present invention also includes an aggregation-induced luminescent material containing the phosphor according to the present invention. Such an aggregation-induced luminescent material includes at least the phosphor according to the present invention, and further includes, for example, a solvent, a non-solvent, a poor solvent, a polymer compound, a combination thereof, or the like of the phosphor according to the present invention. .

  Furthermore, the phosphor according to the present invention can be suitably used for the following applications.

<PH stimulus responsive material, stimulus response material for metal sensor, stimulus response material for pressure sensor>
When the non-solvent or poor solvent of the phosphor according to the present invention is added to the solution in which the phosphor according to the present invention is dissolved, and the phosphor according to the present invention is precipitated and aggregated, the near ultraviolet excitation light Flashes on. It has been found that the emission intensity decreases when an acid is added to the liquid containing the aggregated molecules of the phosphor according to the present invention. This is because, by adding an acid, the amino group bonded to the C atom at the 2-position or 3-position of the maleimide is protonated, the conjugated system is cleaved, and the planarity between the benzene ring and the maleimide ring of the phenylamino group is impaired. This is probably because

  Thus, the phosphor according to the present invention can be used as a pH stimulus responsive material because it emits light or is quenched by the surrounding pH in an aggregated state. Therefore, the present invention includes a pH stimulus responsive material comprising the phosphor according to the present invention. Such a pH stimulus responsive material also includes the phosphor according to the present invention, and may further include a solvent such as a solvent, a non-solvent, or a poor solvent.

  In addition, the phosphor according to the present invention changes the wavelength of light emission when the metal is coordinated to the amino group bonded to the C atom at the 2-position or 3-position of maleimide. Can be used.

  Furthermore, the phosphor according to the present invention can be used as a stimulus-responsive material for a pressure sensor because, when a pressure is applied, the crystal is distorted and the wavelength of light emission changes.

<Light wavelength conversion material>
Moreover, the phosphor according to the present invention can be suitably used as a light wavelength conversion material. For example, in a silicon crystal solar cell, light having a wavelength shorter than 400 nm and light having a wavelength longer than 1200 nm are not effectively used in sunlight. Therefore, about 56% of solar energy is generated by photovoltaic power generation due to this spectrum mismatch. Does not contribute. In order to solve such a problem, the wavelength region that can contribute to power generation by converting the wavelength of light in the ultraviolet region or infrared region that does not contribute to power generation in the solar spectrum using the light wavelength conversion material for solar cells. A method has been proposed in which a layer that emits light is provided on the light-receiving surface side of the solar cell. The phosphor according to the present invention can be suitably used as such a light wavelength conversion material for solar cells. Since the phosphor according to the present invention has good dispersibility, wavelength conversion can be performed in an aggregated state in which concentration quenching is suppressed, and sunlight can be used efficiently and stably.

  Alternatively, the phosphor according to the present invention, for the purpose of promoting the growth of plants by converting light having a wavelength not used for plant photosynthesis into an absorption wavelength range necessary for photosynthesis, such as an agricultural sheet, a gardening sheet, etc. It can be suitably used as an optical wavelength conversion material for agricultural and horticultural wavelength conversion coating materials.

  Furthermore, the phosphor according to the present invention is a light wavelength conversion material for signs, display boards, safety goods, etc. using the characteristic that light is emitted even in bad weather conditions by converting invisible ultraviolet light into visible light emission. Can be suitably used.

  Therefore, the present invention includes a light wavelength conversion material comprising the phosphor according to the present invention. Such a light wavelength conversion material may also be a polymer film, a polymer sheet, a polymer molded body or the like containing the phosphor according to the present invention, or the phosphor according to the present invention and a film, a sheet or a molded body. It may be a film-forming composition or a molding composition containing a polymer compound that forms a polymer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by an Example.

  The emission spectrum and excitation spectrum in the solid state and in the liquid were measured using a PERKIN ELMER LS50B Luminescence Spectrometer.

(Synthesis Example 1)
Preparation of dimethylanilinofumarate Aniline (1.97 g, 21.2 mmol) was slowly added dropwise while cooling dimethyl acetylenedicarboxylate (1.49 g, 10.5 mmol) with ice water, and the mixture was stirred at room temperature for 4 hours. As the stirring continued, the solution became yellow. After the reaction, the raw material was distilled off under reduced pressure to obtain yellow oily dimethylanilinofumarate in a yield of 90%.
¹ H-NMR (CDCl ₃ ): δ 9.67 (s, 1H); 7.28 (t, J = 7.6, 8.4 Hz, 2H); 7.09 (t, J = 7.6, 7.2 Hz, 1H); 6.90 (d, J = 7.6 Hz, 2H); 5.39 (s, 1H); 3.74 (s, 3H); 3.69 (s, 3H).

(Synthesis Example 2)
Production of dimethyl-p-toluidino fumarate While cooling dimethyl acetylenedicarboxylate (1.04 g, 7.31 mmol) with ice water, aniline (0.756 g, 7.06 mmol) was slowly added dropwise, and the mixture was stirred at room temperature for 48 hours. As the stirring continued, the solution became yellow. After the reaction, the raw material was distilled off under reduced pressure to obtain yellow oily dimethyl-p-toluidino fumarate in a yield of 90%.
¹ H-NMR (CDCl ₃ ): δ 9.62 (s, 1H); 7.08 (d, J = 8.0 Hz, 2H); 6.80 (d, J = 8.4 Hz, 2H); 5.33 (s, 1H); 3.73 ( s, 3H); 3.69 (s, 3H); 2.30 (s, 3H).

Example 1: Production of 2-anilino-Nn-hexylmaleimide
Dimethylanilinofumarate (0.188 g, 0.799 mmol) was dissolved in methanol (5 ml), n-hexylamine (0.243 g, 2.40 mmol) was added dropwise with stirring, and stirring was continued at room temperature for 24 hours. After stirring, the yellow solid that had precipitated was collected by filtration using cooled methanol. The obtained solid was recrystallized from methylene chloride and 2-propanol to obtain yellow crystals in a yield of 26%. Melting point 133 ° C. FIG. 1 shows the H-NMR spectrum of 2-anilino-Nn-hexylmaleimide obtained in Example 1.
¹ H-NMR (CDCl ₃ ): δ 7.40 (t, J = 8.4, 7.6 Hz, 2H); 7.23 (s, 1H); 7.15 (t, J = 6.8, 8.4 Hz, 1H); 7.14 (d, J = 8.4 Hz, 2H); 5.50 (s, 1H); 3.53 (t, J = 7.2, 7.6 Hz, 2H); 1.61 (m, 2H), 1.31 (m, 6H), 0.88 (m, 3H).

[Example 2: Production of 2-anilino-Nn-octylmaleimide]
Dimethylanilinofumarate (0.195 g, 0.829 mmol) was dissolved in methanol (5 ml), octylamine (0.326 g, 2.52 mmol) was added dropwise with stirring, and stirring was continued at room temperature for 24 hours. After stirring, the yellow solid that had precipitated was collected by filtration using cooled methanol. The obtained solid was recrystallized from methylene chloride and 2-propanol to obtain yellow crystals in a yield of 26%.
¹ H-NMR (CDCl ₃ ): δ 7.40 (t, J = 8.0, 8.0 Hz, 2H); 7.25 (s, 1H); 7.17-7.13 (m, 3H); 5.50 (s, 1H); 3.53 (t , J = 7.2, 7.2 Hz, 2H); 1.61 (m, 2H); 1.28 (m, 10H); 0.87 (m, 3H).

[Example 3: Production of 2-p-toluidino-Nn-hexylmaleimide]
Dimethyl-p-toluidinofumarate (0.188 g, 0.755 mmol) is dissolved in methanol (5 ml), and n-hexylamine (0.222 g, 2.19 mmol) is added dropwise with stirring, followed by stirring at room temperature for 48 hours. I kept doing it. After stirring, the yellow solid that had precipitated was collected by filtration using cooled methanol. The obtained solid was recrystallized with methylene chloride and 2-propanol to obtain yellow crystals with a yield of 28%.
¹ H-NMR (CDCl ₃ ): δ 7.20 (d, J = 8.4 Hz, 2H); 7.17 (s, 1H); 7.04 (d, J = 8.4 Hz, 2H); 5.43 (s, 1H); 3.52 ( t, J = 7.2, 7.6 Hz, 2H); 2.35 (s, 3H); 1.61 (m, 2H); 1.30 (m, 6H); 0.88 (m, 3H).

[Example 4: Luminescence in the solid state]
When a solid sample of aminomaleimide obtained in Examples 1 to 3 was irradiated with near ultraviolet light (315 nm to 400 nm, wavelength with the strongest lamp intensity: 352 nm) using a black light blue lamp, all emitted light in a solid state. showed that. In addition, as the black light blue lamp, an ultraviolet ray box standard type strong type (manufactured by Mutual Science Glass Co., Ltd.) was used.

  In addition, a solid sample of aminomaleimide obtained in Examples 1 to 3 was uniformly placed in a solid powder cell, and all were excited at 400 nm, and an emission spectrum was measured with a spectrofluorometer (FP-8500, JASCO Corporation). ). The maximum emission wavelength was observed at 492 nm for 2-anilino-N-hexylmaleimide, 495 nm for 2-anilino-N-octylmaleimide, and 499 nm for 2-p-toluidino-N-hexylmaleimide. The result of measuring the emission spectrum of is shown as an example.

  From this result, it can be seen that the maximum emission wavelength changes in the region from 492 nm to 499 nm due to the difference in the carbon chain of the substituent or saturated alkyl. It is considered that the emission wavelength was tuned in detail by changing the electronic state by changing the substituent or by changing the planarity of the imide moiety and the amine moiety.

[Example 5: Aggregation-induced luminescence]
In ¹ mL of a tetrahydrofuran (THF) solution of 2-anilino-Nn-hexylmaleimide obtained in Example 1 (4 mmol L ⁻¹ ), the ratio of water to the total weight of the mixture was 70% by weight and 72% by weight, respectively. 4 mL of a mixed solvent of THF and water was added so as to be 80% by weight, and near ultraviolet rays (315 nm to 400 nm, wavelength with the strongest lamp intensity: 352 nm) were irradiated using the same black light blue lamp as in Example 4. As a result, an increase in the emission intensity associated with the aggregation was confirmed. The results are shown in FIG. In the state where 2-anilino-Nn-hexylmaleimide was dissolved in THF (the ratio of water was 70% by weight), almost no light emission was observed. However, as the proportion of water increases, 2-anilino-Nn-hexylmaleimide precipitates and aggregates to produce luminescence. It was also confirmed that the emission intensity increased with the amount of aggregation. From this result, it can be seen that 2-anilino-Nn-hexylmaleimide exhibits aggregation-induced luminescence.

  In addition, a mixture of 2-anilino-Nn-hexylmaleimide with a ratio of water to the total weight of the mixture of 70% by weight, 72% by weight, and 80% by weight, respectively, and a THF / water mixed solvent at 335 nm. FIG. 4 shows the result of measuring the emission spectrum after excitation. As shown in FIG. 4, it was confirmed that the emission intensity increased as the water concentration increased.

[Example 6: Luminescence in a solid film]
2-anilino-Nn-hexylmaleimide (2.7 mg) of Example 1 was dissolved in 5 mL of toluene. 30 mL of ethylene-vinyl acetate copolymer (EVA), polystyrene (PS), or polymethyl methacrylate resin (PMMA) is added to 1 mL of this 2-anilino-Nn-hexylmaleimide toluene solution (0.54 mg / mL). mg was dissolved, cast on a silicon substrate at 70 ° C., and dried by heating at 130 ° C. for 20 minutes.

  All the prepared films were pale yellow transparent films. When this film was irradiated with a black light blue lamp, light was emitted as shown in FIG.

  When the emission spectrum of the film having an excitation wavelength of 400 nm was measured, the maximum emission wavelength as shown in FIG. 6A was observed. In the figure, powder refers to aminomaleimide crystals that are not dissolved in the polymer. From this result, it was found that the aminomaleimide of the present invention emits light even in a polymer film (film), and the emission wavelength varies depending on the type of polymer matrix. FIG. 6B shows the emission spectra of 2-anilino-Nn-hexylmaleimide powder, EVA film, and PS film of Example 1.

[Example 7: pH response of luminescence]
2-anilino-Nn-hexylmaleimide (11 mg) obtained in Example 1 was dissolved in 10 mL of tetrahydrofuran (THF). By adding 4 mL of water to 1 mL of this 2-anilino-Nn-hexylmaleimide in THF (4 mmol L ⁻¹ ), luminescence was observed as shown in FIG. The emission spectrum of this mixture of 2-anilino-Nn-hexylmaleimide and a THF / water mixed solvent is shown in FIG.

  When 2 mL of 35% HCl aqueous solution was added to this mixture, no light was emitted as shown in FIG. 7B, and the emission intensity was reduced.

  This is considered to be because the amino group was protonated by adding an acid, and as a result, the planarity of the aminomaleimide unit was impaired. This result indicates that the phosphor of the present invention has pH responsiveness.

[Example 8: Quantum yield of aminomaleimide of the present invention]
When the quantum yield of the aminomaleimide of the present invention in the production methods of Examples 1 to 3 was measured with a spectrofluorometer (FP-8500, JASCO Corporation), it was 34%, 35%, and 16 respectively. %Met.

  As a reference aminomaleimide (Reference Example 1-6), the inventors of the present application have a substituted or unsubstituted phenyl group or a substituted or unsubstituted benzyl bonded to the N-position of maleimide, and 2-position or 3-position of maleimide. An aminomaleimide in which a substituted or unsubstituted phenylamino group (anilino group) is bonded to this atom was prepared. The aminomaleimide for reference had a low quantum yield of 8% or less in all cases (Table 1).

  In fact, since the aminomaleimide of the present invention has a high quantum yield, fluorescence that is strong enough to be observable with the naked eye as compared with the reference aminomaleimide phosphor was observed.

  The reference aminomaleimide of Reference Example 3-5 was substituted or unsubstituted aniline or substituted or unsubstituted benzylamine in place of the saturated alkylamine of Example 1-3 in the second step of the two-step process herein. (See the method for producing aminomaleimide of Reference Example 3-5 below). In this case, the reaction temperature had to be 150 ° C. to produce a reference aminomaleimide.

  The reference aminomaleimides of Reference Examples 1, 2, and 6 are substituted with a substituted or unsubstituted phenyl group or substituted or unsubstituted benzyl at the N-position of maleimide, and substituted with the 2- or 3-position atom of maleimide. Aminomaleimide formed by bonding an unsubstituted phenylamino group (anilino group) is reacted with 1,4-dihydro-1,4-diarsinic acid dianhydride at 60 to 120 ° C. for 1 to 10 hours. A two-step process comprising a first step and a second step in which a primary amine is reacted with the 1,4-dihydro 1,4-diarsinine tetracarboxydiimide obtained in the first step at 80 to 150 ° C. for 4 to 24 hours. (See the method for producing aminomaleimide in Reference Examples 1, 2 and 6 below).

[Reference Example 3: Method for producing 2-m-toluidino-Np-tolylmaleimide]
Dimethyl acetylenedicarboxylate (0.395 g, 2.78 mmol) and m-toluidine (1.16 g, 10.8 mmol) were stirred at 150 ° C. for 4 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled in a freezer, the precipitated black-brown solid was washed with methanol, filtered, and the obtained solid was recrystallized with methylene chloride and methanol to give yellow 2-m-toluidino-Np. -Crystals of tolylmaleimide were obtained with a yield of 3%.
¹ H-NMR (CDCl ₃ ): δ 7.37-7.29 (m, 3H); 7.18 (t, J = 8.0, 8.0 Hz, 3H); 7.00 (d, J = 9.6 Hz, 3H); 5.66 (s, 1H ); 2.40 (s, 3H); 2.39 (s, 3H).

[Reference Example 4: Method for producing 2-p-bromoanilino-Np-bromophenylmaleimide]
Dimethyl acetylenedicarboxylate (0.399 g, 2.81 mmol) and p-bromoaniline (1.89 g, 11.0 mmol) were stirred at 150 ° C. for 1 hour under a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, the precipitated black-brown solid was washed with methanol, filtered, and the obtained solid was recrystallized with methylene chloride and methanol to give yellow 2-p-bromoanilino-Np. -Crystals of bromophenylmaleimide were obtained with a yield of 5%.
¹ H-NMR (CDCl ₃ ): δ 7.60 (d, J = 8.8 Hz, 2H); 7.55 (d, J = 8.8 Hz, 2H); 7.32 (d, J = 8.8 Hz, 2H); 7.09 (d, J = 9.2 Hz, 2H); 5.65 (s, 1H).

[Reference Example 5: Method for producing 2-anilino-Np-tolylmaleimide]
Dimethylanilinofumarate (0.195 g, 0.830 mmol) and p-toluidine (0.357 g, 3.33 mmol) were stirred at 150 ° C. for 3 hours under a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, the precipitated black-brown solid was washed with methanol, filtered, and the resulting solid was recrystallized with methylene chloride and methanol to give yellow 2-anilino-Np-tolyl. Maleimide crystals were obtained with a yield of 6%.
¹ H-NMR (CDCl ₃ ): δ 7.49-7.33 (m, 6H); 7.23 (d, J = 8.4 Hz, 2H); 7.10 (d, J = 8.4 Hz, 2H); 5.61 (s, 1H); 2.37 (s, 3H).

[Reference Example 1: Method for producing 2-anilino-N-phenylmaleimide]
1. 1. Production of cis-1,4-dihydro-1,4-dimethyl-1,4-diarsinine-2,3,5,6-tetracarboxylic dianhydride (cis-DHDADA) 1-1. Production of cis-1,4-dihydro-1,4-dimethyl-2,3,5,6-tetrakis (tert-butoxycarbonyl) -1,4-diarsinine (cis-DHDAtBu)
Synthesis and Characterization of Stereoisomers of 1,4-Dihydro-1,4-diarsinines Arita, M .; Naka, K .; Morisaki, Y .; Nakahashi, A .; Chujo, Y. Organometallics, 28 (20), 6109- According to the method described in 6113 (2009), iodomethane (50 g, 0.35 mol) was added to an aqueous sodium hydroxide solution (10 mol / L, 100 mL) of diarsenic trioxide (25 g, 0.13 mol), and the mixture was refluxed at 85 ° C. for 3 hours. After the reaction, 200 mL of ethanol was added to form a white precipitate, which was filtered and dissolved in 200 mL of distilled water. Then, 1 L of ethanol was added for reprecipitation to obtain white powder of disodium methylarsonate.
¹ H-NMR (D ₂ O): δ 1.50 (s, 3H).

A 50% aqueous phosphinic acid solution (150 g) was added to disodium methylarsonate sufficiently dried at room temperature under reduced pressure, and the mixture was stirred at 70 ° C. for 3 hours. The yellow organic phase separated into two phases was washed with an aqueous sodium hydroxide solution (2.5 mol / L) and then distilled under reduced pressure to obtain yellow liquid cyclo- (MeAs) ₅ .

Under a nitrogen atmosphere, cyclo- (MeAs) ₅ (3.97 g, 8.83 mmol) was added to a toluene solution (200 mL) of ditert-butylacetylene dicarboxylate (10.0 g, 44.2 mmol) refluxed at 120 ° C. and stirred for 12 hours. did. Thereafter, the solvent was distilled off under reduced pressure, and the residue was washed with methanol to remove components soluble in methanol. After drying under reduced pressure at room temperature, it was dissolved in a minimum amount of methylene chloride, and ethanol was slowly added so as not to disturb the liquid surface, followed by recrystallization to obtain transparent columnar crystal cis-DHDAtBu in a yield of 31.3%.
¹ H-NMR (CDCl ₃ ): δ 1.52 (s, 6H); 1.50 (s, 1H).

1-2. Production of cis-1,4-dihydro 1,4-dimethyl 1,4-diarsinine 2,3,5,6-tetrakiscarboxylic dianhydride (cis-DHDADA)
cis-DHDAtBu (2.2 g, 3.4 mmol) was added to formic acid (500 ml), and the mixture was stirred at 120 ° C. for 24 hours. After cis-DHDAtBu dissolved in formic acid, the liquid color changed from colorless and transparent to yellow and transparent in 5 minutes. The reaction mixture was concentrated under reduced pressure, chloroform was added to the residue to extract a yellow component, and the resulting yellow solution was concentrated under reduced pressure. Then, formic acid (500 ml) was added again and the mixture was stirred under reflux for 24 hours. Was concentrated under reduced pressure to obtain cis-DHDADA as yellow crystals in a yield of 93%.
¹ H-NMR (CDCl ₃ ): δ 1.81 (As-CH ₃ ). ¹³ C-NMR (CDCl ₃ ): δ 162.99; 152.77; 10.09. FT-IR: 1830 cm ⁻¹ , 1800 cm ₋₁ (C = O) 1240 cm ⁻¹ (CO)

2. Production of cis-DHDADI-phenyl A toluene solution of cis-DHDADA (371.9 g, 1.00 mmol) and aniline (273.8 g, 2.73 mmol) was refluxed for 2 hours under a nitrogen atmosphere. After the solvent was distilled off under reduced pressure, recrystallization was performed with a mixed solvent of methylene chloride / methanol to obtain yellow crystals in a yield of 52.3%.
¹ H-NMR (CDCl ₃ ): δ 7.51-7.37 (m, 5H); 1.79 (s, 3H). FAB-HR-MS (m / z): calculated for C ₂₂ H ₁₆ As ₂ N ₂ O ₄ , 552.2226; found, 521.9545. Anal. Calculated for C ₂₂ H ₁₆ As ₂ N ₂ O ₄ : C, 50.60; H, 3.09. Found: C, 50.43; H, 2.93.

3.2 Production of 2-anilino-N-phenylmaleimide
A aniline solution (0.5 mL) of cis-DHDADI-phenyl (33.5 mg, 0.064 mmol) was stirred at 130 ° C. for 7 hours. After the reaction, aniline was distilled off under reduced pressure, methanol was added and recrystallization was performed to obtain yellow 2-anilino-N-phenylmaleimide crystals in a yield of 30.1%.

[Reference Example 2: Method for producing 2-p-toluidino-Np-tolylmaleimide]
Under a nitrogen atmosphere, cis-DHDADA (104.2 mg, 0.28 mmol) and p-toluidine (1675.2 mg, 15.63 mmol) were stirred at 150 ° C. for 9.5 hours. After the reaction, p-toluidine was distilled off under reduced pressure, methanol was added to perform recrystallization, and yellow 2-p-toluidino-Np-tolylmaleimide crystals were obtained in a yield of 41.6%.
¹ H-NMR (CDCl ₃ ): δ 7.37 (s, 1H); 7.27 (s, 4H); 7.21 (d, J = 8.1 Hz, 6H); 7.09 (d, J = 8.5 Hz, 1H); 5.59 (s, 1H); 2.38 (s, 1H); 2.36 (s, 1H).
¹³ C-NMR (CDCl ₃ ): δ 171.57; 167.22; 142.69; 137.60; 135.74; 130.32; 129.70; 128.99; 125.88, 119.03; 88.42; 21.16;

[Reference Example 6: Method for producing 2-anilino-Np-bromophenylmaleimide]
1. Preparation of cis-DHDADI-p-bromophenyl (cis-DHDADI-p-BrPh) A chlorobenzene solution (15 mL) of cis-DHDADA (375.4 mg, 1.01 mmol) and p-bromoaniline (371.1 mg, 2.16 mmol) under a nitrogen atmosphere ) Was stirred at 130 ° C. for 3 hours. After the solvent was distilled off under reduced pressure, the residue was dissolved in methylene chloride and recrystallized by adding methanol to obtain yellow crystals of cis-DHDADI-p-BrPh in a yield of 37.4%.
¹ H-NMR (CDCl ₃ ): Δ7.62 (d, J = 8.8 Hz, 2H); 7.32 (d, J = 8 Hz); 1.79 (s, 3H).

2.2 Preparation of 2-anilino-Np-bromophenylmaleimide A aniline solution (2.5 mL) of cis-DHDADI-p-BrPh (61.4 mg, 0.0903 mmol) was stirred at 120 ° C. for 7 hours under a nitrogen atmosphere. After the reaction, aniline was distilled off under reduced pressure, methanol was added and recrystallization was performed to obtain yellow 2-anilino-Np-bromophenylmaleimide crystals in a yield of 43.4%.
¹ H-NMR (CDCl ₃ ): δ 7.64-7.18 (m. 10H); 5.67 (s. 1H).

  The phosphor according to the present invention has a relatively simple structure composed of carbon, nitrogen, oxygen, and hydrogen, and a novel organic material that can precisely control the emission color in the visible region by the electronic effect and steric effect depending on the type of substituent. It is a phosphor, and overcomes the problem of concentration quenching under conventional organic phosphor high concentration conditions, and also exhibits aggregation-induced luminescence. Therefore, it is not only used in a wide range of fields such as dye lasers, bioimaging, organic EL light-emitting dyes, and light wavelength conversion materials for solar cells, but it is also an aggregation-induced light-emitting molecule with secondary amines. In organic and industrial fields, new applications of organic phosphors such as pressure sensors, solvent vapor sensors, pH sensors, and metal sensors are expected.

Claims (7)

A phosphor comprising aminomaleimide represented by the following general formula (1).
(In general formula (1),
A represents a substituted or unsubstituted saturated alkyl group,
B represents a substituted or unsubstituted phenyl group. ) The phosphor according to claim 1, wherein A is a linear or branched substituted or unsubstituted saturated alkyl group having 3 to 20 carbon atoms.   An aggregation-induced luminescent material comprising the phosphor according to claim 1.   A pH stimulus responsive material comprising the phosphor according to claim 1.   An optical wavelength conversion material comprising the phosphor according to claim 1. Aminomaleimide represented by the following general formula (4).
(In general formula (4),
R ¹ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a halogen atom,
n represents 4 or 6-10. ) A phosphor comprising aminomaleimide represented by the following general formula (1).
(In general formula (1),
A represents a substituted or unsubstituted saturated alkyl group,
B represents an unsubstituted phenyl group. )