阅读说明：本技术 一种离子化室温磷光材料、复合磷光材料及其制备方法和应用 (Ionized room-temperature phosphorescent material, composite phosphorescent material, and preparation methods and applications thereof ) 是由 徐炜 贺庆国 程建功 于 2020-12-22 设计创作，主要内容包括：本发明涉及有机光电材料技术领域,特别是涉及一种离子化室温磷光材料、复合磷光材料及其制备方法和应用。该材料具有如式I所示的结构：其中,R-1、R-2、R-3、R-4各自独立地选自氢原子、烷基、羟基取代的烷基、胺基取代的烷基、烷氧基、酯基、酰基、三氟烷基、硅烷基或腈基。该材料的制备方法,将有机胺与羰基化合物反应,其中,羰基化合物的α位至少包含一个带有氢原子的碳原子。该制备方法主要基于铵阳离子和烯醇阴离子层状夹心结构,层间具有独特的二维离子化网络结构,在常温常压无保护气体条件下,实现晶体的自发组装生长,并具有很好的柔性印刷性能,该离子化室温磷光材料有望用于低成本室温磷光图案制备。(The invention relates to the technical field of organic photoelectric materials, in particular to an ionized room temperature phosphorescent material, a composite phosphorescent material, and preparation methods and applications thereof. The material has a structure as shown in formula I: wherein R is 1 、R 2 、R 3 、R 4 Each independently selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyl-substituted alkyl group, an amine-substituted alkyl group, an alkoxy group, an ester group, an acyl group, a trifluoroalkyl group, a silane group, and a nitrile group. The preparation method of the material comprises the step of reacting organic amine with carbonyl compound, wherein alpha position of the carbonyl compound at least comprises one carbon atom with hydrogen atom. The preparation method is mainly based on an ammonium cation and enol anion layered sandwich structure, a unique two-dimensional ionization network structure is arranged between layers, spontaneous assembly growth of crystals is realized under the conditions of normal temperature and normal pressure without protective gas, the flexible printing performance is good, and the ionized room-temperature phosphorescent material is expected to be used for preparing low-cost room-temperature phosphorescent patterns.)

1. An ionized room temperature phosphorescent material is characterized by having a structure shown as a formula I:

wherein R is₁、R₂、R₃、R₄Each independently selected from hydrogen atom, alkyl, hydroxyl substituted alkyl, amino substituted alkyl, alkoxy, ester group, acylA trifluoroalkyl group, a silane group or a nitrile group.

2. The ionized room temperature phosphorescent material of claim 1, further comprising at least one of the following technical features:

1) the ionized room temperature phosphorescent material is of an ion-pair sandwich structure formed by enol ions and ammonium ions, wherein the enol ions form enol ion layers, the ammonium ions form ammonium ion layers, and the ammonium ion layers are positioned between the enol ion layers;

2) the oxygen atom and the hydrogen atom adjacent to the nitrogen atom form a hydrogen bond;

3)R₁、R₂each independently selected from H, alkyl, hydroxy-substituted alkyl or amino-substituted alkyl;

4)R₃、R₄each independently selected from-A₁-A₂、-A₁-A₃-A₂or-A₃-A₁-A₂Wherein, in the step (A),

A₁selected from carbonyl, (sulph) sulfonyl, (phosph) yl or nitroxyl;

A₂selected from alkyl, hydroxyl substituted alkyl, amino substituted alkyl, alkoxy, ester group, carboalkyl, trifluoroalkyl, silane group or nitrile group;

A₃selected from alkylene groups.

3. The method of claim 1 or 2, further comprising at least one of the following technical features:

a)R₁、R₂a cyclic structure or a repeating unit of a heterocyclic group which may be formed together with the N atom to which it is bonded;

b)R₃、R₄may form a cyclic structure of a heterocyclic group or a high molecular structure of a repeating unit together with the N atom to which it is bonded.

4. The method for preparing an ionized room temperature phosphorescent material of any one of claims 1 to 3, wherein an organic amine is reacted with a carbonyl compound, wherein the α -position of the carbonyl compound comprises at least one carbon atom with a hydrogen atom, and the corresponding hydroxyl position of the enol structure belongs to an acid site;

wherein the organic amine and the carbonyl compound have structures shown in formulas I-1 and I-2 respectively:

5. the method of claim 4, further comprising at least one of the following features:

1) when at least one of the organic amine and the carbonyl compound is a solid, reacting the organic amine with the carbonyl compound in an organic solvent;

2) coating the reaction raw materials on the surface of a substrate;

3) reacting the organic amine with the carbonyl compound according to a chemical dose ratio;

4) the organic amine is selected from ammonia, propylamine, butylamine, diethylamine, di-n-propylamine, diisopropylamine, cyclohexylamine, piperidine, pyridine, piperazine, diethanolamine, hexamethyldisilimine or polyethyleneimine;

5) the alpha position or the beta position of the enol structure corresponding to the carbonyl compound is linked with carbonyl, (sulfenyl), (phosphoryl) or (nitroxyl);

6) the carbonyl compound is selected from the compounds of the following structural general formula:

wherein, B₁、B₂、B₃Each independently selected from the group consisting of alkyl, hydroxy-substituted alkyl, amino-substituted alkyl, alkoxy, ester, carbonyl, trifluoroalkyl, silane, and nitrile.

6. The method of claim 5, further comprising at least one of the following features:

11) in the feature 1), the organic solvent is at least one selected from the group consisting of ethanol, tetrahydrofuran, chloroform and dichloromethane;

12) in feature 1), the preparation method further includes: volatilizing to remove the organic solvent;

21) the feature 2) is that the substrate is at least one selected from the group consisting of filter paper, quartz plate, silicon wafer, and nanomaterial.

7. The method for producing an ionized room temperature phosphorescent material as claimed in claim 5, wherein in the feature 6), B₁、B₂、B₃Can be linked to form a cyclic structure of heterocyclic radical or a high molecular structure of repeating unit.

8. Use of the ionized phosphorescent room temperature material of any of claims 1 to 3 in sensing, catalysis, luminescence and anti-counterfeiting fields.

9. A composite phosphorescent material, which is characterized in that the ionized room temperature phosphorescent material of any one of claims 1 to 3 is used as a side chain group, or is in a blending doping form, and is compounded with a polymer, a metal organic framework material or a covalent organic framework material.

10. Use of the composite phosphorescent material of claim 9 in sensing, catalysis, luminescence and anti-counterfeiting fields.

Technical Field

The invention relates to the technical field of organic photoelectric materials, in particular to an ionized room temperature phosphorescent material, a composite phosphorescent material, and preparation methods and applications thereof.

Background

In the field of photoluminescent materials, organic phosphorescent materials have recently become a research hotspot, and have wide application prospects from digital encryption and biological imaging to optical sensors. The phosphorescent material has strict requirements on the stability of a triplet excited state of the structure and the energy level thereof, and in a traditional phosphorescent system, the phosphorescent material is often an ionic structure in which rare earth elements participate in coordination; in view of the limitation of the cost and reserve of rare earth elements on the wide application of the materials, great progress has been made in recent years in realizing long-life room temperature phosphorescence by using pure organic compounds such as naphthalimide, carbazole compounds, benzophenone compounds, phenothiazine, aromatic carboxylic acid and the like as raw materials. Based on the materials, the room temperature phosphorescence theory is intensively researched by combining experimental trials and theoretical simulation. However, most of these systems are based on aromatic structure design, and the design and synthesis still have great limitations.

Different from the traditional aromatic phosphorescence structure, the unconventional structure, particularly the room temperature phosphorescence of a non-aromatic organic system, is widely concerned, and the room temperature phosphorescence of the unconventional structure has the characteristics of low cost, simple synthesis process, small fluorescence interference, low environmental toxicity and the like. However, due to the electron delocalization effect of aromatic rigid conformation in the conventional system, the triplet excited state can be effectively stabilized, so that in the non-aromatic system, it is very challenging to obtain the corresponding stabilization effect to realize strong emission and long-life room temperature phosphorescence. Meanwhile, the crystallization performance of a non-aromatic system is often poor, the spatial interaction between key units is difficult to control accurately, and the single crystal structure is analyzed to clarify the emission mechanism. Therefore, in view of the above limitation factors, the types of non-aromatic room temperature phosphorescent systems that have been reported so far are very limited.

In view of the above, developing a new material system that does not contain the traditional aromatic ring structure and realizes pure organic room temperature phosphorescence would have important value in theory and application.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide an ionized room temperature phosphorescent material, a composite phosphorescent material, and a preparation method and an application thereof, wherein the preparation method is simple and convenient to operate and low in cost, and can effectively provide an aromatic structure which is relatively rigid and relatively poor in dissolution processing performance and is not used in an organic phosphorescent material, thereby providing a technical and material basis for related applications.

To achieve the above and other related objects, a first aspect of the present invention provides an ionized room temperature phosphorescent material having a structure represented by formula I:

wherein R is₁、R₂、R₃、R₄Each independently selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyl-substituted alkyl group, an amine-substituted alkyl group, an alkoxy group, an ester group, an acyl group, a trifluoroalkyl group, a silane group, and a nitrile group.

Preferably, at least one of the following technical features is also included:

1) the ionized room temperature phosphorescent material is of an ion-pair sandwich structure formed by enol ions and ammonium ions, wherein the enol ions form enol ion layers, the ammonium ions form ammonium ion layers, and the ammonium ion layers are positioned between the enol ion layers;

2) the oxygen atom and the hydrogen atom adjacent to the nitrogen atom form a hydrogen bond;

3)R₁、R₂each independently selected from H, alkyl, hydroxy-substituted alkyl or amino-substituted alkyl;

4)R₃、R₄each independently selected from-A₁-A₂、-A₁-A₃-A₂or-A₃-A₁-A₂Wherein, in the step (A),

A₁selected from carbonyl, (sulph) sulfonyl, (phosph) yl or nitroxyl;

A₂selected from alkyl, hydroxyl substituted alkyl, amino substituted alkyl, alkoxy, ester group, carboalkyl, trifluoroalkyl, silane group or nitrile group;

A₃selected from alkylene groups.

Preferably, at least one of the following technical features is also included:

a)R₁、R₂a cyclic structure or a repeating unit of a heterocyclic group which may be formed together with the N atom to which it is bonded;

b)R₃、R₄may form a cyclic structure of a heterocyclic group or a high molecular structure of a repeating unit together with the N atom to which it is bonded.

The second invention of the present invention provides a preparation method of the ionized room temperature phosphorescent material, wherein organic amine is reacted with a carbonyl compound, wherein the α position of the carbonyl compound at least comprises a carbon atom with a hydrogen atom, and the corresponding hydroxyl position of the enol structure belongs to an acid site;

wherein the organic amine and the carbonyl compound have structures shown in formulas I-1 and I-2 respectively:

preferably, at least one of the following technical features is also included:

1) the organic amine and the carbonyl compound are mostly in solution, no solvent is needed, and in a few cases: when at least one of the organic amine and the carbonyl compound is a solid, reacting the organic amine with the carbonyl compound in an organic solvent;

2) coating the reaction raw materials on the surface of a substrate;

3) reacting the organic amine with the carbonyl compound according to a chemical dose ratio;

4) the organic amine is selected from ammonia, propylamine, butylamine, diethylamine, di-n-propylamine, diisopropylamine, cyclohexylamine, piperidine, pyridine, piperazine, diethanolamine, hexamethyldisilimine or polyethyleneimine. The ammonium ions formed were as follows:

5) the corresponding enol structure alpha position or beta position of the carbonyl compound is linked with carbonyl, (sulfenyl), (phosphorylidene) or (nitrinatoyl) to facilitate to become a multiple hydrogen bond acceptor structure; the enol anion and the ammonium cation with a plurality of protons form a highly stable enol-ammonium ion sandwich structure under the action of multiple hydrogen bonds and ionic bonds, the stabilization effect of an aromatic rigid structure on a triplet excited state in a traditional room temperature phosphorescence system is replaced, and long-life aromatic ring-free organic room temperature phosphorescence is realized;

6) the carbonyl compound is selected from the compounds of the following structural general formula:

wherein, B₁、B₂、B₃Are selected from alkyl, hydroxyl-containing alkyl, amine-containing alkyl, alkoxy, ester, carbonyl, trifluoroalkyl, silane or nitrile groups. The enol ions formed are as follows:

more preferably, at least one of the following technical characteristics is also included:

11) in the feature 1), the organic solvent is at least one selected from the group consisting of ethanol, tetrahydrofuran, chloroform and dichloromethane;

12) in feature 1), the preparation method further includes: volatilizing to remove the organic solvent;

21) the feature 2) is that the substrate is at least one selected from the group consisting of filter paper, quartz plate, silicon wafer, and nanomaterial. The nanomaterial may be a nanomaterial of various dimensions, such as: quantum dots, nanowires, nanoparticles, nanoribbons, and the like.

More preferably, feature 6), B₁、B₂、B₃Can be linked to form a cyclic structure of heterocyclic radical or a high molecular structure of repeating unit, for example, the structural formula of the carbonyl compound is as follows:the enol ions formed are as follows:

the third aspect of the invention provides the application of the ionized room temperature phosphorescent material in the fields of sensing, catalysis, luminescence and anti-counterfeiting. Under the ionization action, a layered crystal structure is formed by spontaneous growth, and the good shape plasticity and the film printing performance of the layered crystal structure are utilized to be applied to a series of fields such as sensing, catalysis, luminescence, anti-counterfeiting and the like.

The fourth aspect of the invention provides a composite phosphorescent material, which is compounded with a polymer, a metal-organic framework material or a covalent organic framework material in a form of taking the ionized room temperature phosphorescent material as a side chain group or blending and doping.

The fifth aspect of the invention provides the application of the composite phosphorescent material in the fields of sensing, catalysis, luminescence and anti-counterfeiting.

The invention has the following advantages and beneficial effects:

1) the phosphorescence system avoids the use of an aromatic ring structure, creates an anion-cation sandwich structure beneficial to phosphorescence and luminescence, has the phosphorescence service life as long as 0.33 second and the quantum efficiency as high as 25.94 percent, and has important value on phosphorescence-related theories and application practices.

2) According to the application, an enol ion-ammonium ion is utilized to form an anion and cation pair, so that the structure self-assembly is realized, and the long-life room-temperature phosphorescence emission life is longer than microsecond level.

3) The liquid crystal material is mixed with pure liquid raw materials, spontaneously grows to form a layered crystal structure, can be directly printed on planes such as filter paper and the like to form a film, is simple, convenient and efficient, and can be applied to a series of fields such as sensing, catalysis, luminescence, anti-counterfeiting and the like.

4) Compared with aromatic hydrocarbon structures, the aliphatic compound raw materials are easy to obtain, low in cost and less in environmental pollution.

5) The method utilizes the ionization network structure to stabilize pure organic room temperature phosphorescence, is a new phosphorescence mechanism except an aromatic ring stabilization mechanism, provides a new design thought and an effective control means for the research on room temperature phosphorescence materials and triplet excited states at present, and has guiding significance for the application based on related theories.

6) This application is because the used raw materials aliphatic hydrocarbon compound of preparation material is mostly liquid, can effectively avoid using extra solvent and introducing impurity molecule in the structure, promotes the controllability and the purity of structure. The pure liquid raw material is also plastic in shape, can provide possibility for room temperature phosphorescent thin film patterns printed at low cost, and is expected to be applied to a series of fields such as sensing, catalysis, luminescence, anti-counterfeiting and the like.

Drawings

FIG. 1 shows the chemical molecular structure of the ion pair material of examples 1 to 9.

FIG. 2 is a graph showing the UV-VIS absorption spectra of examples 1-4.

FIG. 3 is a phosphorescence emission spectrum of examples 1 to 4.

FIG. 4 is a graph of phosphorescent lifetime for examples 1-4.

Fig. 5 is a crystal structure obtained by single crystal XRD of example 1.

Fig. 6 is a crystal structure obtained by single crystal XRD of example 2.

FIG. 7 is a photograph of phosphorescent emission from the crystalline structures of examples 1-4.

FIG. 8 is a phosphorescent photograph of a self-assembled film on filter paper printed by a brush pen in example 1.

Detailed Description

The technical solution of the present invention will be further specifically described below by way of specific examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, all parts and percentages are by weight, unless otherwise specified, and the equipment and materials used are commercially available or commonly used in the art. The methods in the following examples are conventional in the art unless otherwise specified.

Example 1

Acetyl acetone enol anion-diethylamine cation ACAC^-/Et₂NH₂ ⁺：

Mixing acetylacetone and diethylamine in equimolar mode to form an anion-cation pair structure, and obtaining a pure crystal form product without impurities.

Example 2

Acetylacetone enol anion-ammonium cation ACAC^-/NH₄ ⁺：

Mixing acetylacetone and hexamethyl disilimine in equal molar ratio to form anion-cation pair structure and obtain pure crystal form product without impurities.

Example 3

Trifluoroacetylacetone enol formAnionic-diethylamine cation CF₃AC^-/Et₂NH₂ ⁺：

Mixing trifluoroacetylacetone and diethylamine in an equimolar way to form an anion-cation pair structure, and obtaining a pure crystal form product without impurities.

Example 4

Trifluoroacetylacetone enol anion-ammonium cation CF₃AC^-/NH₄ ⁺：

Mixing trifluoroacetylacetone and hexamethyldisilimine in equimolar mode to form an anion-cation pair structure, and obtaining a pure crystal form product without impurities.

Example 5

Acetoacetic acid ethyl enol type anion-diethylamine cation ACAC^-/Et₂NH₂ ⁺：

Mixing the ethyl acetoacetate and diethylamine in an equimolar way to form an anion-cation pair structure, thus obtaining a pure crystal form product without impurities.

Example 6

Acetoacetic acid ethyl ester enol type anion-ammonium cation ACAC^-/NH₄ ⁺：

Mixing the ethyl acetoacetate and hexamethyl disilimine in an equimolar way to form a cation-anion pair structure, thus obtaining a pure crystal form product without impurities.

Example 7

Bis-trifluoromethyl-1-3-propanedione enol anion-diethylamine cation CF₃AC^-/Et₂NH₂ ⁺：

Mixing bis (trifluoromethyl) 1-3-propanedione and diethylamine in equimolar mode to form an anion-cation pair structure, and obtaining a pure crystal form product without impurities.

Example 8

Bis-trifluoromethyl-1-3-propanedione enolate anion-ammonium cation CF₃AC^-/NH₄ ⁺：

Mixing bis (trifluoromethyl) 1-3-propanedione and hexamethyl disilimine in equimolar mode to form an anion-cation pair structure, and obtaining a pure crystal form product without impurities.

Example 9

Acetylacetone enol anion-polyethyleneimine cation ACAC^-/PEI：

Excessive (the molar ratio of the acetylacetone to the reactive active sites of the polymer is more than 1:1) and polyethyleneimine (the polymerization degree is 10000) are mixed to form an anion-cation pair structure, so that a pure crystal form product without impurities is obtained.

FIG. 2 is a UV-VIS absorption spectrum of examples 1-4:

shows four representative crystal materials prepared from aliphatic hydrocarbon raw materials, all having absorption wavelength and intensity close to those of aromatic organic materials, wherein ACAC^-/Et₂NH₂ ⁺And ACAC^-/NH₄ ⁺The maximum absorption peaks of the crystal are at 280nm and 284nm, while CF₃AC^-/Et₂NH₂ ⁺And CF₃AC^-/NH₄ ⁺The maximum absorption peaks of the crystals were red-shifted to 308nm and 315 nm. The crystal containing trifluoromethyl substituent and ammonium ion has stronger ion interaction, longer absorption wavelength and larger integral area, so that fine modulation of the absorption wavelength can be realized by adjusting the substituent groups on enol ion and ammonium ion.

FIG. 3 is a phosphorescence emission spectra for examples 1-4, as determined using the Delta-Hub phosphorescence lifetime component of the HORIBA Fluoro-Max 4plus fluorescence spectrometer:

as can be seen from FIG. 3, the ionic crystals have the same phosphorescence emission peak at 530nm, but different intensities, CF₃AC^-/Et₂NH₂ ⁺Is 43636, CF₃AC^-/NH₄ ⁺25448, ACAC^-/Et₂NH₂ ⁺Is 7119, ACAC^-/NH₄ ⁺Is 4303. Here, the enhancement of the emission from the ammonium ion pair by the diethylamine cation was 1.71 times and 1.65 times in the acetylacetone system and the trifluoroacetylacetone system, respectively. Trifluoromethyl substituent makes ammonium radical system and diethylammoniumThe emission intensity of the system is increased 6.13 times and 5.91 times of the original emission intensity respectively.

The result of accurate measurement by the integrating sphere method also shows that the emission efficiency value and the emission intensity have the same trend. ACAC^-/Et₂NH₂ ⁺The phosphorescent efficiency of the crystal was 6.32%, which is ACAC^-/NH₄ ⁺Crystal 3.69% phosphorescence efficiency 1.71 times, and CF₃AC^-/Et₂NH₂ ⁺The phosphorescent efficiency of the crystal was 25.94%, which was CF₃AC^-/NH₄ ⁺Crystal 15.88% phosphorescence efficiency is 1.63 times.

FIG. 4 is a plot of phosphorescence lifetime for examples 1-4, as determined using the Delta-Hub phosphorescence lifetime component of the HORIBA Fluoro-Max 4plus fluorescence spectrometer.

The different attenuation trends of the four lifetime curves can be visually seen in the graph, corresponding to different phosphorescence emission lifetimes, ACAC^-/NH₄ ⁺The service life of the crystal reaches 0.326 second and is far longer than that of ACAC^-/Et₂NH₂ ⁺Lifetime of the crystal 596 microseconds; the lifetime of the CF3AC-/NH4+ crystals was 145.44 microseconds and the lifetime of the CF3AC-Et2NH2+ crystals was 2.13 microseconds. Thus, the substituent groups on the enolate ion and the ammonium group are modulated, enabling fine modulation of the phosphorescent emission wavelength.

FIG. 5 is the crystal structure obtained by single crystal XRD of example 1, as measured by Brooks APEX-II CCD diffractometer, in which acetylacetone (ACAC) molecules exist in enolic anion state, while every two ACAC molecules are in coplanar state, and form stable dimer hydrogen bond supramolecular structure by hydrogen bonding with four hydrogen atoms adjacent to nitrogen atom on diethylamine cation. The dimer structure is used as a repeating unit and is horizontally and orderly arranged along a (100) crystal face of the crystal to finally form an ion interaction layer which is mainly composed of an acetylacetone ion layered structure, alternating acetylacetone molecular layers and diethylamine.

Fig. 6 shows the crystal structure obtained by the single crystal XRD of example 2, which is also a layered ion network structure, but because the ammonium ions allow dense hydrogen bonding, no dimer structure is observed in the structure, but rather a more specific two-dimensional ionized network structure, the extending direction of which is the (002) crystal plane.

FIG. 7 is a photograph of phosphorescence emission of the crystalline structure of examples 1-4 taken under the conditions of 20 times magnification and 64 frame rate by a fluorescence microscope, showing fluorescence images of 4 self-assembled ionic phosphorescent crystals after excitation is stopped at 0s, 0.25s, 0.5s, 0.75s and 1s, demonstrating that the lifetime of the non-aromatic ionic crystals is long enough to allow direct observation of the residual glow phenomenon under an optical microscope and the naked eye.

Fig. 8 is a phosphorescent photograph of a self-assembled film on a filter paper printed by a brush pen in example 1, and it can be illustrated that the non-aromatic ion room temperature phosphorescent crystal system can be directly printed on the filter paper in the form of brush writing using a rapid and convenient self-assembly process due to the absence of any solid components in the raw material, resulting in a high quality room temperature phosphorescent pattern, such as "pl. Therefore, this strategy is promising for designing and manufacturing low-cost shape-adaptive and large-scale printable room temperature phosphorescent materials.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.