Donor-receptor type chiral macrocyclic eutectic material as well as preparation method and application thereof

Abstract

The invention discloses a donor-acceptor type chiral macrocyclic eutectic material as well as a preparation method and application thereof, and belongs to the field of luminescent materials. The chemical formula of the eutectic material is C76H52N6O12, and the chemical formula is C76H52N6O12. The crystal belongs to an orthorhombic system, and the space group is P212121. The invention also provides a preparation method of the eutectic material, and the preparation method comprises the following steps: dissolving cyclotrimeric naphthalene diimine and pyrene in a solvent, and reacting to obtain the eutectic material. When the cyclotrimeric naphthalene diimine is in an R type, an R type eutectic material is obtained; and when the cyclotrimeric naphthalene diimine is S-type, obtaining the S-type eutectic material. The synthesis method has the advantages of simplicity, low production cost, mild reaction conditions and suitability for large-scale production. The material is a crystalline pure organic eutectic material, has the optical properties of circularly polarized light of dark red and near-infrared emission and two-photon excited dark red and near-infrared emission, is easy to process and stable, and has certain device potential.

Description

Technical Field

[0001] The present application relates to a donor-acceptor chiral macrocyclic eutectic material and a preparation method and application thereof, belonging to the field of luminescent materials. Background Art

[0002] Circularly polarized light (CPL) is a chiral feature generated by the rotational difference between left-handed and right-handed circularly polarized light. CPL materials have a wide range of applications in three-dimensional display, biomedicine, information encryption, anti-counterfeiting and other fields. Initially, circularly polarized light could be generated by combining a polarizer and a quarter-wave plate, but this method inevitably leads to significant optical losses. Alternatively, the direct integration of chiral units and luminophores can lead to materials with CPL activity, thereby reducing optical losses by approximately 50%. In recent years, new materials reported in this field include compounds such as chiral organic molecules, chiral metal oxide clusters, and chiral covalent organic frameworks (CCOFs). However, most of these materials have difficulty in achieving tunable emission, especially circularly polarized emission in the deep red and near-infrared wavelength ranges.

[0003] Two-photon absorption (TPA) materials have the ability to shift the excitation wavelength from visible light to the near-infrared (NIR) region by simultaneously absorbing two photons. Compared to visible light, NIR light exhibits less photodamage, lower optical scattering, higher energy density, and superior optical penetration. Therefore, it is widely used in photodynamic therapy, disease monitoring, information encoding, and other fields. Summary of the Invention

[0004] This application constructs a co-crystal with synergistic electron donor-acceptor properties into a material with CPL and TPA properties, introduces chiral groups into the donor-acceptor co-crystal, and successfully prepares a multifunctional crystalline organic optical material with both circularly polarized luminescence and two-photon absorption properties. The non-chiral donor pyrene (Py) and the chiral acceptor cyclotrimethylnaphthalene diimide (R-NDI and S-NDI) are selected to construct the supramolecular assembled donor-acceptor chiral macrocyclic co-crystals R-NDI-Py and S-NDI-Py. The molecules form a pair of enantiomeric crystalline luminescent materials through non-covalent π-π interaction, CH···π, CH···O and intermolecular charge transfer (ICT). The peak of their circularly polarized luminescence is at 675nm, and the emission spectrum covers the deep red and near-infrared regions. The maximum luminescence asymmetry factor (g lum ) is +1.5×10 -2 and -1.0×10 -2 The material's two-photon excited fluorescence emission peak is located at 680nm, and the emission spectrum covers the deep red and near-infrared regions. The two-photon absorption cross-section value at 810nm is as high as 2.277×10 3 GM.

[0005] According to a first aspect of the present application, a donor-acceptor type chiral macrocyclic eutectic material is provided.

[0006] A donor-acceptor chiral macrocyclic eutectic material, the chemical formula of the eutectic material is C 76 H 52 N6O 12 ;

[0007] It belongs to the orthorhombic crystal system and its space group is P212121.

[0008] Optionally, the eutectic material includes R-type and S-type;

[0009] When it is an R-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z=4, Dc=1.218~1.220g / cm 3 ;

[0010] When it is an S-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z=4, Dc=1.218~1.220g / cm 3 .

[0011] Specifically, when it is an R-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z = 4, Dc = 1.219 g / cm 3 .

[0012] When it is an S-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z = 4, Dc = 1.219 g / cm 3 .

[0013] Optionally, the eutectic material is dark red rod-shaped crystals.

[0014] Optionally, the circularly polarized light emission of the eutectic material is in the range of 550 to 850 nm, with an emission peak at 675 nm.

[0015] Optionally, the two-photon excited fluorescence emission peak of the eutectic material is located at 680 nm, and the emission spectrum covers the deep red and near-infrared regions.

[0016] Through intermolecular charge transfer interactions induced by donor and acceptor self-assembly, the material's circular dichroism signal extends to 400-800 nm, and a rare circularly polarized emission in the deep red and near-infrared region is obtained. The circularly polarized emission of R-NDI-Py and S-NDI-Py occurs in the 550-850 nm region, with an emission peak at 675 nm, and the spectra exhibit distinct mirror symmetry. This is attributed to the effective electron delocalization and polarization caused by the intermolecular charge transfer interactions between the donor and acceptor self-assembly systems. The material's two-photon excited fluorescence emission peaks at 680 nm, and the emission spectrum covers the deep red and near-infrared regions. When the incident laser excitation wavelength of the organic cocrystal powder is fixed at 1000 nm, the fluorescence intensity of R-NDI-Py is observed to be linearly proportional to the square of the laser power, indicating that this upconversion emission originates from a two-photon absorption mechanism. Further comparison of the two-photon emission spectra of the samples with those of a standard rhodamine B dye determined a TPA cross-section value of 2.277×10 3 GM.

[0017] According to a second aspect of the present application, a method for preparing the above-mentioned eutectic material is provided, wherein pyrene (Py) and cyclotrimethylnaphthalene diimide (NDI) are used as a donor and an acceptor, respectively, to prepare the eutectic material.

[0018] The method for preparing the eutectic material mentioned above comprises the following steps: dissolving cyclotrimer naphthalenediimide and pyrene in a solvent, and reacting the mixture to obtain the eutectic material.

[0019] Optionally, the cyclotrimer naphthalenediimide includes R type and S type;

[0020] When the cyclotrimethylnaphthalene diimide is in R-type, an R-type eutectic material is obtained;

[0021] When the cyclotrimethylnaphthalene diimide is in S-type, an S-type eutectic material is obtained.

[0022] Optionally, the molar ratio of cyclotrimer naphthalenediimide to pyrene is 1:0.5-2.

[0023] Specifically, the molar ratio of cyclotrimer naphthalenediimide to pyrene is 1:1.

[0024] Optionally, the reaction temperature is 60-120°C;

[0025] The reaction time is 48 to 72 hours.

[0026] Specifically, the reaction temperature is 85°C;

[0027] The reaction time is 72 h.

[0028] Optionally, the solvent is N,N-dimethylformamide and acetonitrile.

[0029] As a specific embodiment, the preparation method includes:

[0030] Pyrene and cyclotrimethylnaphthalene diimide were mixed in a molar ratio of 1:1, dissolved in N,N-dimethylformamide and acetonitrile solution, dispersed in a 10 ml glass vial, placed in an 85 ° C oven for reaction for 72 hours, and cooled to room temperature to obtain dark red crystals.

[0031] According to a third aspect of the present application, an application of the eutectic material described above is provided.

[0032] The above-mentioned eutectic material is used as a crystalline organic circularly polarized light-emitting material.

[0033] The cyclotrimethylnaphthalene diimide eutectic series exhibits both circularly polarized luminescence and two-photon absorption properties. This new crystalline, purely organic eutectic material is applied to both circularly polarized luminescence and two-photon absorption, resulting in a multifunctional crystalline organic optical material with excellent luminescence properties.

[0034] The beneficial effects of this application include:

[0035] 1) The donor-acceptor chiral macrocyclic eutectic material provided in this application is a crystalline, pure organic eutectic material. It exhibits the optical properties of deep red and near-infrared circularly polarized emission, as well as deep red and near-infrared emission under two-photon excitation. Its circularly polarized emission peak is located near 675nm, making it the longest emission peak reported for a crystalline organic circularly polarized luminescent material. The material is easy to process and stable, which gives it considerable potential for device application.

[0036] 2) The preparation method of the donor-acceptor chiral macrocyclic eutectic material provided in this application has the advantages of simple synthesis, low production cost, mild reaction conditions, and suitability for large-scale production. The resulting crystalline pure organic eutectic circularly polarized luminescent material has the advantages of good crystallinity and high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the structure of the synthesized crystalline pure organic eutectic material.

[0038] Figure 2 These are the solid-state UV and fluorescence spectra of compounds R-NDI-Py, R-NDI, and Py.

[0039] Figure 3 These are the circular dichroism and circular polarization spectra of compound R / S-NDI-Py.

[0040] Figure 4 This is the two-photon absorption spectrum and fitting curve of compound R-NDI-Py. DETAILED DESCRIPTION

[0041] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0042] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0043] Unless otherwise specified, conventional methods were used for testing, and instrument settings were those recommended by the manufacturer.

[0044] Example 1

[0045] R-NDI (11.0 mg, 0.01 mmol) and pyrene (2.6 mg, 0.01 mmol) were dissolved in a 10 ml glass bottle with 2 ml of DMF and 2 ml of acetonitrile and heated in an 85°C oven for 72 h. After cooling to room temperature, deep red crystals of R-NDI-Py were observed with a yield of approximately 75%. The preparation method of S-NDI-Py cocrystal was the same. Its structure was determined by single crystal diffractometry, and the test results showed that its structural formula is C 76 H 52 N6O 12 , belongs to the orthorhombic crystal system, and the space group is P21212 1， The unit cell parameters of R-NDI-Py are α=β=γ=90°, the unit cell volume is Z = 4, Dc = 1.219 g / cm 3 ; The structural formula of S-NDI-P is C 76 H 52 N6O 12 , belongs to the orthorhombic crystal system, the space group is P212121, and the S-NDI-Py unit cell parameters are α=β=γ=90°, the unit cell volume is Z = 4, Dc = 1.219 g / cm 3 Its structural diagram is as follows. Figure 1 As shown, the asymmetric structural unit contains an R-NDI molecule and a Py molecule, wherein R-NDI has a triangular inner hole of approximately (The distance between the center of mass of the naphthalenediamine plane was calculated without excluding the van der Waals radius.) Two closely connected R-NDI molecules are arranged almost vertically, establishing multiple CH·π interactions and CH·O hydrogen bonds between them. Two adjacent R-NDI molecules on the left and right and above and below are simultaneously stacked face-to-face with a Py molecule, forming a sandwich-like stacking pattern. Therefore, the Py molecule fills the gaps between the R-NDI molecules, enabling them to stack together to form a two-dimensional helical superstructure induced by the donor-acceptor type supramolecular assembly.

[0046] Example 2

[0047] UV-visible diffuse reflectance data of the powder samples were recorded at room temperature using a PerkinElmer Lamda-950 UV spectrophotometer with a scan range of 250–800 nm using BaSO₄ as a standard (100% reflectance). Photoluminescence spectroscopy was performed on a UV / V / NIR fluorescence spectrometer (FLS1000, Edinburgh, Germany). Figure 2 As shown, R-NDI-Py, Py, and R-NDI are excited at 375, 415, and 375 nm, respectively. The two-photon excitation fluorescence emission peak of R-NDI-Py material is located at 680 nm, and the emission spectrum covers the deep red and near-infrared regions. The two-photon absorption cross-section value at 810 nm is as high as 2.277×10 3 GM.

[0048] Example 3

[0049] Circular dichroism spectra were measured using KBr microspheres on a MOS-450 polarimeter. Circularly polarized luminescence spectra were measured on a JASCOCPL-300 instrument. For R-NDI-Py, the excitation wavelength was 375 nm, the measurement range was 850–550 nm, and the high voltage was 950 V. For S-NDI-Py, the excitation wavelength was 375 nm, the measurement range was 850–550 nm, and the high voltage was 900 V. The measurement results are shown in Figure 2. Figure 3 As shown, the spectrum shows obvious mirror symmetry, the circularly polarized luminescence is in the 550-850nm region, the peak of the circularly polarized luminescence is at 675nm, the emission spectrum covers the deep red and near-infrared regions, and the maximum luminescence asymmetry factor (g lum ) is +1.5×10 -2 and -1.0×10 -2 .

[0050] Example 4

[0051] Pure organic co-crystal materials of appropriate size were selected and two-photon microscopic images were captured using a laser fluorescence confocal microscope (A1MP) with excitation wavelengths of 720, 800 and 900 nm. The up-conversion fluorescence spectrum was measured using a multifunctional fluorescence spectrometer (FLS980). Microscope photographs under natural light and 365 nm ultraviolet light were recorded using an ECLIPES Si RS biological microscope. In the range of 770-810 nm, two-photon excitation fluorescence spectra were obtained using an Astrella / OperA single femtosecond laser as the excitation source, and the emission spectrum was collected using an Ocean Optics spectrophotometer (QE65 Pro). While keeping the test conditions consistent, the solid-state TPEF intensity of R-NDI-Py and R-NDI was compared with the TPEF intensity of Rhodamine B (Rhodamine B, RhB), and the TPEF cross sections of R-NDI-Py and R-NDI were quantitatively calculated. The results are shown in Figure 2. Figure 4 As shown in Figure 2, when the incident laser excitation wavelength is fixed at 1000 nm, the fluorescence intensity of R-NDI-Py is observed to be linearly related to the square of the laser power, indicating that this upconversion emission originates from a two-photon absorption mechanism. By further comparing the two-photon emission spectrum of the sample with that of the standard Rhodamine B dye, the TPA cross-section value is determined to be 2.277×10 3 GM.

[0052] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A donor-acceptor chiral macrocyclic eutectic material, characterized in that: The chemical formula of the eutectic material is C 76 H 52 N6O 12 ; It belongs to the orthorhombic crystal system and its space group is P212121.

2. The eutectic material according to claim 1, characterized in that The eutectic material includes R type and S type; When it is an R-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z=4, Dc=1.218~1.220g / cm 3 ; When it is an S-type eutectic material, the unit cell parameters are α=β=γ=90°, the unit cell volume is Z=4, Dc=1.218~1.220g / cm 3 .

3. The eutectic material according to claim 1, characterized in that The circularly polarized light emission of the eutectic material is in the region of 550 to 850 nm, with an emission peak at 675 nm.

4. The eutectic material according to claim 1, characterized in that The two-photon excited fluorescence emission peak of the eutectic material is located at 680 nm, and the emission spectrum covers the deep red and near infrared regions.

5. The method for preparing the eutectic material according to any one of claims 1 to 4, characterized in that: The following steps are involved: The cyclotrimer naphthalenediimide and pyrene are dissolved in a solvent and reacted to obtain the eutectic material.

6. The preparation method according to claim 5, characterized in that The cyclotrimer naphthalenediimide includes R type and S type; When the cyclotrimethylnaphthalene diimide is in R-type, an R-type eutectic material is obtained; When the cyclotrimethylnaphthalene diimide is in S-type, an S-type eutectic material is obtained.

7. The preparation method according to claim 5, characterized in that The molar ratio of cyclotrimer naphthalenediimide to pyrene is 1:0.5-2.

8. The preparation method according to claim 5, characterized in that The reaction temperature is 60-120°C; The reaction time is 48 to 96 hours.

9. The preparation method according to claim 5, characterized in that The solvent is N,N-dimethylformamide and acetonitrile.

10. Use of the eutectic material according to any one of claims 1 to 4 as a crystalline organic circularly polarized light-emitting material.

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