CN113072929B

CN113072929B - Sandwich type organic supermolecule fluorescent polymer and preparation method and application thereof

Info

Publication number: CN113072929B
Application number: CN202110384373.3A
Authority: CN
Inventors: 黄坤林; 张愿; 陈新; 夏畅; 胡敏
Original assignee: Chongqing Normal University
Current assignee: Chongqing Normal University
Priority date: 2021-04-09
Filing date: 2021-04-09
Publication date: 2022-04-12
Anticipated expiration: 2041-04-09
Also published as: CN113072929A

Abstract

The invention provides a sandwich type steel wire ropeThe organic supermolecular polymer is formed from anion layer and cation chain, and its chemical general formula is [ (H)₂pip)(Hbpeb)]_nBelonging to the monoclinic system, space group is P2(1)/c, unit cell parameter

In the general formula (II)₂pip^‑Is a semi-rigid triorganic carboxylic acid H₃pip is deprotonated by 1 proton, Hbpeb⁺Is obtained by bpeb obtaining 1 proton, said H₃The structure of pip is shown as formula I; the bpeb structure is shown as a formula II,

the polymer provided by the invention has higher thermal stability, stably exists in solvents such as water, acetonitrile and the like, emits green fluorescence when the maximum peak wavelength of solid fluorescence emission of the polymer is 549nm, emits green fluorescence when the solution of the polymer is used for emitting green fluorescence, has higher sensitivity when being used for ion detection, and can also be used for preparing fluorescent materials and devices. The preparation method adopted by the invention has mild conditions and the highest yield reaches about 52 percent.

Description

Sandwich type organic supermolecule fluorescent polymer and preparation method and application thereof

Technical Field

The invention belongs to the technical field of advanced luminescent materials, and particularly relates to a sandwich type organic supermolecule fluorescent polymer and a preparation method and application thereof.

Background

Supramolecular chemistry, which was pioneered by scholars represented by Lehn, became an important subject field for the development of new materials. The luminescent solid material has important application value in sensing, nonlinear optics, catalysis, electroluminescence and imaging. The green material is a commercial example, and the fluorescent solid chemical substances with the peak wavelength of 530-550 nm found naturally or artificially are fewer. In the design and synthesis of supramolecular polymers, how to reasonably select and match organic functional components to synthesize fluorescent materials with specific emission wavelengths, and meanwhile, the relationship between the structure and the luminescence performance is studied in a fine manner still faces huge challenges. The currently reported organic supramolecular polymers with luminescence properties have less thermal stability higher than 300 ℃, and how to design and synthesize a relatively stable fluorescent solid material with certain practical application value is a challenging subject.

Transition metal ion Fe³⁺、Zn²⁺、Co²⁺、Mg²⁺And Cu²⁺Etc. which play an important role in living systems at appropriate concentrations, excessive accumulation of ions disrupts the intracellular balance of organisms, resulting in dysfunction, and in severe cases, may cause a number of diseases including cancer, heart disease, neuronal degeneration, etc. Therefore, it is highly desirable to detect them with high selectivity and high sensitivity. In the current research, the supramolecular fluorescent polymer becomes a novel photosensitive material with potential application value due to the characteristics of adjustable structure, various light-emitting modes, good thermal stability and chemical stability and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the sandwich type organic supramolecular fluorescent polymer, the novel substance has a green fluorescence emission peak at 549nm, has high thermal stability, and can be used for preparing fluorescent materials and devices and performing fluorescence detection on heavy metal ions.

In order to achieve the above object, according to a first aspect of the present invention, the present invention provides the following solutions: a sandwich type organic supermolecular fluorescent polymer with general chemical formula of [ (H)₂pip)(Hbpeb)]_nBelonging to the monoclinic system, space group is P2(1)/c, unit cell parameter

In the chemical general formula, the component H₂pip^-Is a semi-rigid triorganic carboxylic acid H₃pip is deprotonated by 1 proton, and the fraction Hbpeb⁺Is obtained by obtaining 1 proton from the N-component bpeb; said H₃The structure of pip is shown as formula I, the structure of bpeb component is shown as formula II,

further, the sandwich type organic supramolecular fluorescent polymer is characterized in that 1 crystallographically independent H is contained in an asymmetric unit of a microscopic crystal structure of the sandwich type organic supramolecular fluorescent polymer₂pip^-And 1 Hbpeb⁺Preparing components; said H₂pip^-The components are constructed into two dimensions (H) by 4 different O-H.O hydrogen bonds₂pip^-)_nAnionic supramolecular layered structures, i.e. (H)₂pip^-)_nThe anion layer is connected by hydrogen bonds as shown in the formula III, and particularly, the anion layer comprises two rings with different sizes; component Hbpeb⁺Are connected by N-H.N hydrogen bond to form one-dimensional (Hbpeb)⁺)_nThe cation chain is connected by hydrogen bonds as shown in a formula IV; (H)₂pip^-)_nAnionic layer and (Hbpeb)⁺)_nThe cationic chain is further expanded into a sandwich type three-dimensional organic supramolecular polymer,

according to a second aspect of the present invention, the present invention provides a process for the preparation of the above mentioned sandwich type organic supramolecular polymer: with H₃pip, bpeb and HNO₃Or byH₃pip、bpeb、HNO₃And Zn (NO)₃)₂·6H₂O or Cd (NO)₃)₂·4H₂O is used as a raw material, a mixed solvent of acetonitrile and water is used as a medium, and the preparation method adopts a solvothermal synthesis method. Preferably, only with H₃pip, bpeb and HNO₃The sandwich type organic supermolecular polymer is prepared by taking a mixed solvent of acetonitrile and water as a medium and adopting a solvothermal synthesis method.

Further, the preparation method specifically comprises the following steps:

(1) mixing the raw materials and a solvent to form a reaction system, and placing the reaction system in a closed container; the raw material H₃pip：bpeb：Zn(NO₃)₂·6H₂O or Cd (NO)₃)₂·4H₂O：HNO₃The mass ratio of substances is 1: 1: 0-2: 2-5; the volume ratio of the solvents acetonitrile and water is 1: 9;

(2) and (3) placing the reaction system at room temperature, stirring for 10-30min, then heating the reaction system to 110-130 ℃, reacting for 3-5 days, naturally cooling to obtain blocky crystals, and then filtering and drying.

Preferably, said H in step (1)₃pip：bpeb：HNO₃The mass ratio of (1): 1: 3.

preferably, H in the reaction system₃The initial mass concentration of pip or bpeb was 3.3 mmol/L.

Preferably, the reaction temperature in step (2) is 120 ℃, and the drying means natural drying in the air at room temperature after the crystals are washed with distilled water.

According to a third aspect of the invention, the invention also provides an application of the sandwich type organic supramolecular fluorescent polymer prepared by the preparation method in preparation of a fluorescent composite material or detection of heavy metal ferric ions.

Compared with the prior art, the invention has the following beneficial effects:

(1) the sandwich type organic supermolecular fluorescent polymer provided by the invention is constructed by an anion layer and a cation chain, and in the spatial structure, H is₂pip^-And Hbpeb⁺The components form a sandwich type three-dimensional supramolecular polymer with alternating yin and yang through abundant strong hydrogen bonds. The organic supermolecule fluorescent polymer has higher thermal stability and stably exists in solvents such as water, acetonitrile and the like; under 365nm ultraviolet light, the flaky crystal presents brighter green; at room temperature, the maximum peak wavelength of solid fluorescence emission of the polymer is 549nm (emission wavelength range is 450-800nm), green fluorescence is emitted, and Stokes shift reaches 222 nm; and the strongest emission peak wavelength of the aqueous solution is 517nm (emission wavelength range 400-750nm) in a visible light region, and green fluorescence is also emitted, so that the aqueous solution has higher sensitivity when being used for ion detection.

(2) The preparation conditions of the novel substance provided by the invention are mild, and the highest yield of the supramolecular polymer prepared by the method provided by the invention is about 52%. Researches show that when a new organic supermolecular fluorescent polymer structure is prepared under solvothermal conditions, metal ions are sometimes required to be added for induction, but in the invention, the polymer can be successfully prepared under the condition of not adding the metal ions, the yield is slightly improved, and the preparation method is more green, economic and environment-friendly. The sandwich type organic supermolecule fluorescent polymer provided by the invention can be used for preparing fluorescent materials and devices and detecting ferric ions.

Drawings

FIG. 1 is an X-ray powder diffraction pattern of the sandwich type organic supramolecular fluorescent polymer of the invention;

FIG. 2 is a thermogravimetric plot of the sandwiched organic supramolecular fluorescent polymer of the present invention;

FIG. 3 is an infrared spectrum of the sandwich type organic supramolecular fluorescent polymer of the invention;

FIG. 4 shows a sandwich type organic supramolecular fluorescent polymer of the invention, and a diagram (a) in FIG. 4 shows H in the polymer structure₂pip^-The components are connected by hydrogen bonds, and the figure (b) shows H in the polymer structure₂pip^-The component forms two-dimensional (H) through strong O-H … O hydrogen bond₂pip^-)_nAnionic layer, (c) diagram shows Hbpeb in the polymer structure⁺Formation of the connection between the components by hydrogen bondsOne dimension (Hbpeb)⁺)_nA cationic chain;

FIG. 5 is a three-dimensional structure diagram of the sandwich type organic supramolecular fluorescent polymer of the invention;

FIG. 6 shows ligand H₃Room temperature solid state fluorescence spectrum of pip;

FIG. 7 is a graph of room temperature solid state fluorescence spectrum of the supramolecular fluorescent polymer of the invention (inset is a fluorescent photograph of the crystal under UV lamp);

FIG. 8 is a fluorescence spectrum of the supramolecular fluorescent polymer of the invention for detecting cations;

FIG. 9 shows a sandwich type organic supramolecular fluorescent polymer pair Fe³⁺Detecting the fluorescence spectrum of the sample;

FIG. 10 shows the difference in fluorescence intensity and Fe in the fluorescence detection of the present invention³⁺Linear plot of concentration.

Detailed Description

The process of the present invention will be described in detail with reference to specific examples. The sandwich type organic supramolecular polymer provided by the invention can be abbreviated as OSP (organic supramolecular polymer). The method carries out X-ray single crystal diffraction test on the final product, and analyzes to obtain the accurate electronic structure of the final product; and performing a series of characterizations such as infrared, X-ray powder diffraction, thermogravimetry, fluorescence, etc. on the final product to determine that the chemical composition general formula is [ (H)₂pip)(Hbpeb)]_n. With H₃The amount of pip used is based on the calculated yield, i.e.on H in the composition of the product OSP₂pip^-The mass of the supermolecule solid which is theoretically obtained is calculated, and the ratio of the actually obtained product mass to the former is the yield. In the invention H₃The Chinese name for pip is 5- (4-carboxyphenoxy) isophthalic acid and the Chinese name for the component bipyridine bpeb is 1,4' -bis [2- (4-pyridyl) ethenyl]Benzene.

Preparation of sandwich type organic supermolecule fluorescent polymer

Example 1

Taking the following materials according to the specific mass or volume: h₃pip (10.0mg,0.033mmol), bpeb (9.4mg,0.033mmol), acetonitrile CH₃CN(1mL)，H₂O(9mL),HNO₃Solution (15. mu.L, 7mol/L,0.105 mmol). Placing the materials in a 25mL polytetrafluoroethylene lining, stirring for about 15min, sealing in a stainless steel reaction kettle, placing the reaction kettle in an electric heating air blast oven, heating to 120 ℃, reacting for 3 days, naturally cooling to room temperature to obtain a blocky crystal sample, filtering the blocky crystal sample from mother liquor, washing with distilled water, and naturally drying in the air at room temperature.

The prepared crystal sample is subjected to powder diffraction test by an Shimadzu XRD-6100X-ray diffractometer (the result is shown in figure 1, wherein, the abscissa-angle and the ordinate-diffraction intensity), and the peak of the test crystal sample spectrum can be well matched with the peak of a crystal structure simulation spectrum (software Mercury), which indicates that the structure of the obtained crystal sample is the same as that of single crystal data and the purity of the sample is high.

Thermogravimetric data analysis of the obtained crystalline sample showed (as shown in fig. 2, thermogravimetric analysis was performed under nitrogen atmosphere; wherein, abscissa-temperature, ordinate-sample residual rate), from fig. 2, it can be seen that the sandwich type organic supramolecular polymer OSP crystal sample did not lose weight before 310 ℃, and the skeleton collapsed and decomposed after 312 ℃. This indicates that the sandwich type organic supramolecular polymer of the invention has relatively high thermal stability.

Determination of the Single Crystal Structure: selecting proper single crystal, and making the selected single crystal be placed on SMART APEXII CZN single crystal diffractometer (Mo-Ka,

graphite monochromator) were collected at room temperature and X-ray diffraction data were corrected for Lp factor. The crystal structure is solved by direct method, the analysis and refinement of the structure are completed by SHELXTL-97 program package, and then the full matrix least square method F is used²All non-hydrogen atoms are anisotropically refined. The hydrogen atom coordinates of the organic ligand are obtained by theoretical hydrogenation. The main crystallographic data are shown in table 1; the hydrogen bond length is shown in Table 2, wherein the distance D … A is

Therefore H₂pip^-Strong hydrogen bonding between the components, Hbpeb⁺The components are alsoStronger hydrogen bonds are present.

Table 1 main crystallographic data

*R₁＝Σ||F_o|-|F_c||/Σ|F_o|,wR₂＝[Σ_w(F_o ²-F_c ²)²/Σ_w(F_o ²)²]^1/2

TABLE 2 Hydrogen bonding data

Symmetric conversion, #1x +1, -y +3/2, z + 1/2; #2-x +1, -y +1, -z + 1; #3-x +2, y +1/2, -z +3/2

The results show that the OSP has the chemical formula C₃₅H₂₆N₂O₇The formula weight is 586.60, wherein C, H, N element analysis, calculated (%): 71.66, H4.47, N4.78; actually measured (%): c71.60, H4.43, N4.77. FIG. 3 is an infrared spectrum of the novel substance provided by the present invention (in which, abscissa-wavenumber; ordinate-transmittance). FT-IR (KBr, cm)^-1): 3061(w),2458(w),1697(s),1608(vs),1548(s),1375(s),1290(m),1247(vs),1206(m),834(s),763(m,690(m),553(m), indicating that the elemental analysis values were measured by a Perkin-Elmer 2400 elemental analyzer and the infrared spectra were measured by a Perkin Elmer FT-IR Spectrometer Spectrometer with KBr as the base at 400 ion 4000cm^-1Measured within the range.

In the crystal sample, selecting proper single crystal, and analyzing the X-ray single crystal diffraction data to obtain the crystal structure of the sandwich type organic supermolecular fluorescent polymer (shown in figure 4-5). As shown in FIG. 4, each of the H groups has a crystal structure₂pip^-The components all retain 2 carboxyl groups and are different from each other through 4O-H …O strong hydrogen bond to adjacent H₂pip^-Interaction (2.555 and

see table 2), peak of infrared 1697cm^-1And 3061cm^-1The existence of carboxyl is proved; h₂pip^-The component forms two-dimensional (H) through strong O-H … O hydrogen bond₂pip^-)_nAn anionic layer. It is worth mentioning that the anion layer comprises rings with different sizes of a and B, as shown in fig. 4 (B). Component Hbpeb⁺Pass through

Stronger hydrogen bonding, the linkage forming a one-dimensional (Hbpeb)⁺)_nThe cationic chains. (H)₂pip^-)_nAnionic layer and (Hbpeb)⁺)_nThe cationic chains are further extended to three-dimensional sandwich-type organic supramolecular polymers (as shown in figure 5). The characteristics lay a structural foundation for further application of the sandwich type organic supramolecular polymer OSP.

Test H at room temperature₃Solid-state fluorescence spectra of the pips and the prepared crystal samples are shown in FIGS. 6 and 7 (in FIGS. 6 to 7, abscissa-wavelength; ordinate-fluorescence intensity), respectively, and FIG. 6 shows ligand H₃The strongest emission peak of pip is at 381nm (. lamda.)_ex334 nm); the strongest emission peak for bpeb in the literature is around 515 nm. Fig. 7 data analysis shows that: under the excitation of 327nm ultraviolet light at room temperature, the strongest emission peak wavelength of the OSP crystal sample is 549nm (emission wavelength range is 450-800nm), green fluorescence is emitted, and the emission peak wavelength is compared with the emission peak wavelength (lambda) of the raw material bpeb fluorescence_em515nm) a red shift of about 35nm occurred. H₃The pi → n transition of the pip carboxylic acid ligand is very weak and has little contribution to the luminescence of the supramolecular polymer, so the fluorescence mechanism of the sandwich-type organic supramolecular fluorescent polymer OSP is probably mainly attributed to the charge transfer of pi → pi of the bpeb ligand.

The difference between the wavelength of the emission peak and the wavelength of the excitation peak is called Stokes shift, and the Stokes shift in general fluorescent solid materials is usually within 100 nm; the Stokes shift of the fluorescent polymer is 222nm, and can be related to strong hydrogen bonds of O-H.O and N-H.N which are abundant in a spatial structure. As can be seen from the photograph of the middle picture in the upper right corner of FIG. 7, under 365nm ultraviolet light, the bulk crystal prepared by the invention presents brighter green, which is consistent with the data of the fluorescence peak wavelength. In addition, the water solution of the fluorescent polymer prepared by the invention has the strongest emission peak wavelength at 517nm (the emission wavelength range is 400-750nm) in a visible light region and also emits green fluorescence (see figure 8). The excellent thermal stability and fluorescence property indicate that the novel substance has a certain application prospect in the aspects of fluorescent materials, devices and optical detection.

The embodiment is repeated for multiple times, and the quality of OSP obtained actually is kept between 8.2 and 10.0mg based on H₃Calculated for pip, yields were 42.3% to 51.6%.

Example 2

Taking the following materials according to the specific mass or volume: h₃pip(10.0mg,0.033mmol)，bpeb(9.4mg,0.033mmol)，Zn(NO₃)₂·6H₂O(14.9mg，0.05mmol)，CH₃CN(1mL)，H₂O(9mL),HNO₃Solution (10. mu.L, 7mol/L,0.07 mmol). Placing the materials in a 25mL polytetrafluoroethylene lining, stirring for about 20min, sealing in a stainless steel reaction kettle, placing the reaction kettle in an electric heating air blast oven, heating to 110 ℃, reacting for 4 days, naturally cooling to room temperature to obtain a blocky crystal sample, filtering the blocky crystal sample from mother liquor, washing with distilled water, and naturally drying in the air at room temperature.

The product was characterized by powder X-ray diffraction and data similar to example 1 were obtained. It is shown that the crystal structure obtained in example 2 is unchanged and the product purity is higher.

The embodiment is repeated for multiple times, the quality of the OSP obtained actually is maintained to be repeated for multiple times, and the quality of the OSP obtained actually is maintained to be 7.5-8.9 mg based on H₃Calculated for pip, the yield was 38.7% to 45.9%.

Example 3

Taking the following materials according to the specific mass or volume: h₃pip(10.0mg,0.033mmol)，bpeb(9.4mg,0.033mmol)，Cd(NO₃)₂·4H₂O(20.4mg，0.066mmol)，CH₃CN(1mL)，H₂O(9mL),HNO₃Solution (24. mu.L, 7mol/L,0.165 mmol). Placing the materials in a 25mL polytetrafluoroethylene lining, stirring for about 10min, sealing in a stainless steel reaction kettle, placing the reaction kettle in an electric heating air blast oven, heating to 130 ℃, reacting for 5 days, naturally cooling to room temperature to obtain a blocky crystal sample, filtering the blocky crystal sample from mother liquor, washing with distilled water, and naturally drying in the air at room temperature.

The product was characterized by powder X-ray diffraction and data similar to example 1 were obtained. It is shown that the crystal structure obtained in example 3 is unchanged and the product purity is higher.

The embodiment is repeated for multiple times, and the quality of OSP obtained actually is kept between 7.4 and 8.5mg based on H₃Calculated for pip, the yield was 38.2% to 43.9%.

Comparing examples 1-3, it is shown from the comparison of powder diffraction data (as shown in FIG. 1) that the added metal salt does not change the supramolecular structure, but only slightly affects the yield. It was found that when preparing a new structure of organic supramolecular fluorescent polymer under solvothermal conditions, it is sometimes necessary to add metal ions for induction, whereas in the present invention, the polymer can be successfully prepared even without adding metal ions (example 1) with a slight increase in yield.

Secondly, the primary application of the sandwich type organic supermolecular fluorescent polymer

Example 4 fluorescence detection of cations

In view of the good luminescence property of the newly prepared sandwich type organic supramolecular fluorescent polymer in aqueous solution, the selective fluorescence sensing detection of the sandwich type organic supramolecular fluorescent polymer as metal cations is researched. Preparing a sandwich type organic supramolecular fluorescent polymer OSP detection solution in a 250mL conical flask, dissolving 50mg of ground crystal powder in 250mL of water, shaking, uniformly shaking, performing ultrasonic dispersion for 10min to obtain a suspension, filtering to obtain a clear detection solution, and taking 4.5mL of the clear detection solution as a detection solution (uniformly mixing the detection solution before taking each time) in a glass bottle with a number. Respectively measuring 0.5mL of Ag by using a pipette⁺、Ba²⁺、Cu²⁺、Cd²⁺、Mg²⁺、Ni²⁺、Co²⁺、Zn²⁺、Pb²⁺、Cr³⁺、Al³⁺、Fe³⁺Nitrate aqueous solution (concentration 0.01 mol. L)^-1) Adding the mixture into the detection solution, adding 0.5mL of ultrapure water into the detection solution, and uniformly mixing the mixture to be used as a reference sample to be detected.

The fluorescence spectra of the above cationic solutions were measured by FLS1000 Edinburgh fluorescence spectrometer, respectively, under the excitation of light with a wavelength of 281 nm. As can be seen from fig. 8, the luminescence intensity of the sandwich type organic supramolecular fluorescent polymer OSP suspension varies with the change of metal ions. Comparing the luminescence data of the organic supermolecule fluorescent polymer OSP suspension of the sandwich type, Al is found³⁺、Cr³⁺、Pb²⁺、Ni²⁺、Cu²⁺、Cd²⁺、Ag⁺The ions have different degrees of enhancement on the fluorescence of the OSP suspension; in contrast, Zn²⁺、Co²⁺、Ba²⁺、Mg²⁺、Fe³⁺The ions have different degrees of quenching effect on the fluorescence of OSP suspension, wherein Fe is added³⁺Nitrate was found to have the most pronounced effect on fluorescence quenching of OSP suspensions. Heavy metal Fe³⁺Ions are a common source of water contamination. Therefore, the detection liquid prepared from the novel substance can be used for detecting heavy metal Fe³⁺The fluorescence detection of the ions has certain practical significance.

To further explore Fe³⁺For the sensitivity of detection, titration experiments were performed. 2mL of the above test solution was taken as a test solution in a numbered glass vial (the test solution was mixed well before each sampling). Measuring 2.5-500 μ L ferric nitrate aqueous solution (concentration of 0.01 mol. L) with pipette^-1) Adding into the above detection solution, adding 497.5 μ L-0 μ L ultrapure water into the detection solution, and mixing to obtain Fe³⁺The concentration is 10-2000 mu M gradient to be detected solution, and the sample without salt is the reference solution.

Fe was investigated under the same conditions³⁺Ion concentration versus emission intensity of the OSP suspension. As can be seen from FIG. 9, the emission intensity of the organic supramolecular fluorescent polymer suspension is dependent on Fe³⁺The ion concentration is increased from 0 to 2000. mu.MDecrease of Fe³⁺The mechanism of the ion generating quenching effect can be attributed to the ligand pair Fe³⁺Donor-acceptor electron transfer effects of ions. FIG. 10 data analysis shows that when Fe³⁺The fluorescence intensity showed a good linear dependence (R) when the concentration was increased from 10. mu.M to 50. mu.M²0.99073). In addition, from the fluorescence titration data, Fe can be obtained by calculating the limit of detection by the formula LOD of 3 σ/K (where K represents the slope of the quenching curve and σ represents the standard deviation)³⁺The limit of detection (LOD) of the ions was about 7. mu.M. The results show that the novel organic supramolecular polymers are specific for Fe³⁺The ion response is sensitive.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. The sandwich type organic supramolecular fluorescent polymer is characterized by being constructed by an anion layer and a cation chain and having a chemical general formula of [ (H)₂pip)(Hbpeb)]_nBelonging to the monoclinic system, space group is P2(1)/c, unit cell parameter

In the chemical general formula, the component H₂pip^-Is a semi-rigid triorganic carboxylic acid H₃The pip is deprotonated by 1 proton, component Hbpeb⁺Is obtained by obtaining 1 proton from the N-component bpeb; said H₃The structure of pip is shown as formula I, the structure of bpeb component is shown as formula II,

the polymer crystalIn the asymmetric unit of the structure, 1 crystallographically independent H is contained₂pip^-And 1 Hbpeb⁺Preparing components; said H₂pip^-The components are constructed into two dimensions (H) by 4 different O-H … O hydrogen bonds₂pip^-)_nAn anion layer, O-H … O hydrogen bond connection is shown as formula III, the anion layer comprises two rings with different sizes; component Hbpeb⁺Are connected by N-H … N hydrogen bond to form one-dimensional (Hbpeb)⁺)_nThe cationic chain, N-H … N hydrogen bond connection is shown as formula IV; (H)₂pip^-)_nAnionic layer and (Hbpeb)⁺)_nThe cationic chain is expanded into a sandwich type three-dimensional organic supermolecular polymer,

2. a method for preparing the sandwich type organic supramolecular fluorescent polymer as claimed in claim 1, characterized in that the supramolecular fluorescent polymer is H₃pip, bpeb and HNO₃As starting materials or with H₃pip、bpeb、HNO₃And Zn (NO)₃)₂·6H₂O or Cd (NO)₃)₂·4H₂O is used as a raw material, a mixed solvent of acetonitrile and water is used as a medium, and the preparation method adopts a solvothermal synthesis method.

3. Method for the preparation of sandwiched organic supramolecular fluorescent polymers according to claim 2, characterized in that it comprises the following steps:

(1) mixing the raw materials and a solvent to form a reaction system, and placing the reaction system in a closed container; h₃pip：bpeb：Zn(NO₃)₂·6H₂O or Cd (NO)₃)₂·4H₂O：HNO₃The mass ratio of substances is 1: 1: 0-2: 2-5; the volume ratio of the solvents acetonitrile and water is 1: 9;

(2) and (3) placing the reaction system at room temperature, stirring for 10min, then heating the reaction system to 110-130 ℃, reacting for 3-5 days, naturally cooling to obtain blocky crystals, and then filtering and drying.

4. The method for preparing the sandwich type organic supramolecular fluorescent polymer according to claim 3, wherein the H in the step (1)₃pip：bpeb：HNO₃The mass ratio of (1): 1: 3.

5. the method for preparing the sandwich type organic supramolecular fluorescent polymer as claimed in claim 3, wherein H in the reaction system₃The initial mass concentration of pip or bpeb was 3.3 mmol/L.

6. The method for preparing the sandwich-type organic supramolecular fluorescent polymer according to claim 3, wherein the reaction temperature in the step (2) is 120 ℃, and the drying is that the crystal is naturally dried in the air at room temperature after being washed with distilled water.

7. The application of the sandwich type organic supramolecular fluorescent polymer is characterized in that the sandwich type organic supramolecular fluorescent polymer prepared by the method of any one of claims 2 to 6 is applied to the preparation of fluorescent materials and devices or the fluorescent detection of ferric ions.