CN113480739B

CN113480739B - Supermolecule polymer containing two-axis chiral structure and preparation method and application thereof

Info

Publication number: CN113480739B
Application number: CN202110755855.5A
Authority: CN
Inventors: 黄坤林; 张愿; 陈新; 胡敏; 夏畅
Original assignee: Chongqing Normal University
Current assignee: Chongqing Normal University
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2022-06-28
Anticipated expiration: 2041-07-05
Also published as: CN113480739A

Abstract

The invention provides a supermolecule polymer containing two-axis chiral structure, which has a chemical general formula of { [ Cd ]₃(m‑bpt)₂(bpep)₂](H₂O)}_nBelongs to monoclinic system, space group is Pc, cell parameter

In the chemical formula, the component m-bpt^3‑Is a rigid triorganocarboxylic acid m-H₃m-H is obtained by removing 3 protons in bpt₃The bpt structure is shown as formula I; the structure of the component bpep is shown as a formula II,

the crystal structure is revealed, m-bpt and Cd²⁺Forming two-axis chiral structures by coordination, and constructing a two-dimensional coordination polymerization layer; n-ligand bpep is bridged with metal ions to form a zagzig coordination polymer chain, and the zagzig coordination polymer chain is further interpenetrating and woven into a two-dimensional network topological structure; n, O ligand bridged trinuclear cluster generation of rare 3, 10-linkedThe three-dimensional cross pillared coordination polymerization network emits blue fluorescence at the position of 476nm of the strongest emission peak wavelength of a solid sample at room temperature, emits blue fluorescence at the position of 476nm of the strongest emission peak wavelength of an aqueous solution of the three-dimensional cross pillared coordination polymerization network in a visible light region, can be used for preparing fluorescent materials and devices and I^‑And (4) detecting the fluorescence of the ions.

Description

Supermolecule polymer containing two-axis chiral structure and preparation method and application thereof

Technical Field

The invention belongs to the field of advanced luminescent materials, and particularly relates to a supramolecular polymer containing two axial chiral structures and a preparation method and application thereof.

Background

Chiral phenomena are also widely found in nature, such as human hands, natural amino acids, proteins, DNA, etc. Chirality is a basic property of nature, and means that an object cannot coincide with its mirror image, and is usually recognized by (RS) and (DL), and if the two hands of a person are in mirror image relationship and cannot coincide, they are called as left hand (S) and right hand (R). The chiral structure in the chemical field can be generally classified into central chirality, axial chirality, helical chirality and planar chirality, and the first three chiral structures are the most important. The contributions of william standish nors, feiyeh, barrei droplein to chiral catalysis shared the nobel chemical prize in 2001, with the japanese scientist feiyeh winning due to the innovative efforts in axial chirality.

The preparation of the coordination supramolecular polymer with novel spatial structure by using multifunctional organic molecules, metal salts and the like as main raw materials and optimizing experimental conditions is an important frontier in the field of functional material innovation. Since the chemical reaction microscopic process is unclear and the ordered spatial structure of new supramolecules is difficult to predict so far, the preparation of functional supramolecular polymers with novel structures and certain practical value is a challenging subject, and coordinated supramolecular polymers containing two axial chiral structures are rare.

Disclosure of Invention

In view of the above-mentioned deficiencies in the prior art, it is an object of the present invention to provide a supramolecular polymer with two-axis chiral structure, which shows a precise microstructure, shows a blue fluorescence emission peak at 476nm, can be used for the preparation of fluorescent materials and devices, and^-and (4) detecting the fluorescence of the ions.

In order to achieve the purpose, the invention provides the following technical scheme: a supramolecular polymer containing two-axis chiral structures and having a chemical general formula { [ Cd ]₃(m-bpt)₂(bpep)₂](H₂O)}_nBelongs to monoclinic system, space group is Pc, unit cell parameters

In the chemical formula, the component m-bpt^3-Is a rigid triorganocarboxylic acid m-H₃Obtained by eliminating 3 protons in bpt, the m-H₃The structure of bpt is shown as formula I; the structure of the component bpep is shown as a formula II,

by the technical scheme, the crystal structure is revealed, and m-bpt and Cd²⁺Forming two-axis chiral structures by coordination, and constructing a two-dimensional coordination polymerization layer; n-ligand bpep is bridged with metal ions to form a zagzig coordination polymer chain, and the zagzig coordination polymer chain is further interpenetrating and woven into a two-dimensional network topological structure; n, O ligand bridging trinuclear clusters to generate a rare 3, 10-connected three-dimensional cross pillared coordination polymer network; the solid sample of the crystal emits blue fluorescence at the strongest emission peak wavelength of 476nm (the emission wavelength range is 424- ^-And (4) detecting the fluorescence of the ions.

Further, the asymmetric unit comprises 3 crystallographically independent Cd²⁺Ion, 2 m-bpt ^3-2 bpep components and 1 lattice water molecule; each of said m-bpt^3-With 6 Cd²⁺Ion coordination is simplified into a 3-connected secondary structural unit, and the coordination mode is shown as a formula III, wherein m-bpt^3-And Cd²⁺Two mirror symmetry coordination modes are formed after ion coordination, and the two mirror symmetry coordination modes are respectively in R and S configurations; component bpep coordination bridged Cd²⁺Ions, as shown in formula IV; said Cd²⁺The coordination mode of the ions is shown as the formula V, and [ Cd ] is formed by sharing carboxylate radical₃N₄(CO₂)₆]Reduced to 10-linked secondary building blocks; the atomic number symbols in the formulas III to V represent the numbers of atoms in the asymmetric units, the upper right corner of the numbers is marked with a crystal engineering symmetry conversion symbol,

by the technical scheme, m-bpt is in a spatial structure of the polymer^3-Component bridged metal Cd²⁺Ions form a two-dimensional coordination polymerization layer which can be simplified into a two-dimensional 3, 6-connected topological structure, wherein R and S configuration secondary structural units are alternately arranged; the nano-scale N-ligand bpep bridges metal ions Cd1 and Cd2 to construct a zagzig coordination polymerization chain, wherein the included angle of Cd1-Cd2-Cd1 is 120.7 degrees, and the distance of Cd1 & Cd2 is about 2.0 nm; the zagzig polymer chains are further mutually woven into a two-dimensional network topological structure; finally, the secondary structure unit 10-SBU and the two 3-c SBUs are further constructed into a three-dimensional cross pillared coordination polymerization network with three nodes connected by 3,10-, and the supramolecular polymer presents various structures such as interpenetration, pillared and the like in space.

A supermolecular polymer containing two-axis chiral structure is prepared from m-H₃bpt、bpep、Cd(NO₃)₂·4H₂O and HNO₃Using a mixed solution of acetonitrile and water as a solvent, and adopting a solvent thermal synthesis methodAnd (4) preparation.

Further, the solvent thermal synthesis 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 m-H₃bpt：bpep：Cd(NO₃)₂·4H₂O：HNO₃The mass ratio of (a) to (b) is 1: 1: 1.5: 6-8; the volume ratio of the solvents acetonitrile and water is 7: 3;

(2) and (3) placing the reaction system at room temperature, stirring for 10-30 min, then heating the reaction system to 150-160 ℃, reacting for 3-5 days, naturally cooling to obtain irregular crystals, and then filtering and drying.

m-H as described in the optimized step (1)₃bpt：bpep：Cd(NO₃)₂·4H₂O：HNO₃The mass ratio of (1): 1: 1.5: 7.

by the technical scheme, the preparation condition of the supramolecular polymer is mild, and the yield can reach 29.9%.

Further, m-H in the reaction system₃The starting substance of bpt or bpep is present in a concentration of 3.5 mmol/L.

Further, the reaction temperature in the step (2) is 150 ℃, and the drying means that the crystals are naturally dried in the air at room temperature after being washed with distilled water.

The supramolecular polymer containing two axial chiral structures prepared by the preparation method is applied to preparation of fluorescent materials and devices and identification of iodide ions.

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

(1) the supramolecular polymer provided by the invention obtains two rare axial chiral structures in a mirror image relationship; the polymer chains are mutually woven into a two-dimensional network topology; n, O ligands bridge trinuclear clusters to form rare 3, 10-linked three-dimensional cross-pillared coordination polymer networks.

(2) The supramolecular polymer provided by the invention can stably exist in a water solvent; at room temperature, the polymer has the strongest peak wavelength of solid fluorescence emission at 476nm, and at the same time, shoulder peaks appear at 506nm and 450nm, so that blue fluorescence is emitted overall; in the water solution, the strongest emission peak wavelength is also at 476nm of a visible light region, blue fluorescence is emitted, and the detection has higher sensitivity.

(3) The fluorescent supramolecular polymer prepared by the method provided by the invention can be used for preparing fluorescent materials and devices and identifying iodide ions.

Drawings

FIG. 1 is an X-ray powder diffraction pattern of the supramolecular polymer of the present invention;

FIG. 2 is a thermogravimetric plot (N) of the supramolecular polymer of the present invention₂Atmosphere);

FIG. 3 is an infrared spectrum of a supramolecular polymer of the present invention;

FIG. 4 is a graph of room temperature solid state fluorescence spectrum of ligand bpep;

FIG. 5 is a graph of room temperature solid state fluorescence spectrum of supramolecular polymers of the invention (inset is a fluorescent photograph of the crystal under UV light);

FIG. 6 shows the partial crystal structure and coordination mode of the supramolecular polymer of the invention, in which (a) two mirror-image chiral coordination structures with R and S configuration axes and simplified 3-linked secondary structural units and (b) has the composition [ Cd₃N₄(CO₂)₆]Trinuclear clusters and simplified 10-linked secondary building blocks of (a);

FIG. 7 shows that the supramolecular polymer of the present invention is based on m-bpt^3-And [ Cd ]₃(CO₂)₆]A two-dimensional spatial structure of a trinuclear cluster in which (a) m-bpt^3-A two-dimensional coordination polymerization layer constructed by component bridging metal ions, (b) a simplified three-dimensional 3, 6-linked two-dimensional topological graph containing asymmetric structures, wherein [ Cd₃(CO₂)₆]The cluster is simplified into 6-connection nodes, and R and S represent different axial chiral configurations;

FIG. 8 shows that the supramolecular polymer of the invention is based on bpep and Cd²⁺A two-dimensional space structure of metal ions, wherein (a) a nanometer-scale N ligand bpep bridges metal ions Cd1 and Cd2 to construct a zagzig coordination polymer chain, and (b) the zagzig coordination polymer chain is mutually woven into a two-dimensional network topological structure (perspective along the c-axis direction);

FIG. 9 is a 3, 10-linked pillared three-dimensional coordination polymer network of the supramolecular polymer of the present invention;

FIG. 10 is a fluorescence detection spectrum of the supramolecular polymer according to the present invention for anions;

FIG. 11 shows the fluorescence intensity of supramolecular polymers of the invention in different anionic solutions at 476 nm;

FIG. 12 shows the dispersion of supramolecular polymers according to the invention to different concentrations I^-Fluorescence emission spectrum of the ionic solution;

FIG. 13 shows a supramolecular polymer pair I of the present invention^-Stern-Volmer plot of ions.

Detailed Description

The process of the present invention will be described in detail with reference to specific examples. The supramolecular fluorescent polymer provided by the invention can be abbreviated as CdOSP. 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, fluorescence, X-ray powder diffraction, thermogravimetry and the like on the final product to determine that the chemical composition general formula is { [ Cd ]₃(m-bpt)₂(bpep)₂](H₂O)}_n. With m-H₃The amount of bpt was calculated based on the yield, i.e., m-bpt in the composition of the product CdOSP^3-The mass of the obtained complex is calculated, and the ratio of the actually obtained product mass to the former mass is the yield. m-H in the invention₃The English chemical name of bpt is 3,3 ', 5 ' -tricarboxyphenyl, and the English name of bpep is 4,4 ' -bis [2- (4-pyridinyl) ethyl ] phenyl]biphenyl。

Firstly, preparation of the supramolecular polymer

Example 1

Taking the following materials according to the specific mass or volume: m-H₃bpt(10.0mg，0.035mmol)，bpep(12.53mg，0.035mmol)，Cd(NO₃)₂·4H₂O(16.04mg，0.052mmol)，CH₃CN(7mL)，H₂O(3mL)，HNO₃Solution (30. mu.L, 7mol/L, 0.21 mmol). Placing the above materials in 25mL polytetrafluoroethylene lining, stirring for about 10min, sealing in stainless steel reaction kettle, and placing the reaction kettleHeating to 140 deg.C in an electrothermal blowing oven, reacting for 3 days, naturally cooling to room temperature to obtain irregular crystal sample, filtering from mother liquor, washing with distilled water, and naturally drying in air at room temperature.

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

Thermogravimetric data analysis of the obtained crystalline sample shows (see fig. 2, nitrogen atmosphere, abscissa-temperature, ordinate-residue), and it can be known from the figure that the supramolecular polymer crystal sample loses weight by about 1.83% at about 120 ℃, which can be attributed to the separation of guest lattice water molecules (theoretical value 1.1%), and the skeleton collapses and decomposes after 360 ℃. This indicates that the supramolecular polymers of the present invention have relatively high thermal stability.

Determination of the single crystal structure: selecting proper single crystal, and making the selected single crystal be placed on SMARTAPEXII 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 length of the coordination bond is shown in Table 2.

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 length of coordination bond

Symmetric conversion #1x, -y +1, z + 1/2; #2x, -y +1, z-1/2; #3x, y-1, z; #4x +1, -y +2, z + 3/2; #5x-1, -y +1, z + 1/2; #6x, y +1, z

The composition of the obtained supramolecular polymer is { [ Cd ]₃(m-bpt)₂(bpep)₂](H₂O)}_nOf the chemical formula C₈₂H₅₆N₄O₁₃Cd₃The formula weight is 1642.54, wherein C, H, N element analysis, calculated (%): c59.96, H3.44, N3.41; actually measured (%): c59.93, H3.46, N3.43. FIG. 3 is an infrared spectrum (abscissa-wavenumber; ordinate-transmittance) of the novel substance of the present invention. FT-IR (KBr, cm)^-1): 3029(vw), 1601(s), 1565(s), 1429(m), 1363(s), 1015(w), 965(w), 820(m), 769(m), 726(s), 675(w), 543(vs), 414 (w). Description of the drawings: the elemental analysis value is measured by a Perkin-Elmer2400 elemental analyzer; infrared Spectroscopy by a PerkinElmerFT-IR Spectrometer Spectrometer with KBr as the base at 400-4000cm ^-1Measured within the range.

The X-ray single crystal diffraction data are analyzed to obtain the crystal structure of the supramolecular polymer (see figures 6-9). Coordination structure is shown in FIG. 6, each rigid organic component m-bpt^3-With 6 Cd²⁺Ion coordination, which can be simplified to 3-linked secondary building blocks, where m-bpt^3-And Cd²⁺The ions have two coordination modes which are mirror symmetry and are respectively in R and S configurations; the infrared spectrum is 1680-^-1The absorption band of the region disappears, indicating m-H₃The bpt ligand is completely deprotonated in a hydrothermal reaction; bpep per organic component bridged 2 Cd²⁺Ions; in asymmetric units, Cd of different numbers²⁺The ions being coordinated to N or OThe bond lengths were slightly different, but the bond length data were all in the normal coordination bond range. The Cd²⁺Formation of [ Cd ] by sharing carboxylate groups₃N₄(CO₂)₆]Can be reduced to 10-linked secondary building blocks.

Component m-bpt^3-Bridged metal Cd²⁺The ions form a two-dimensional coordination-polymerization layer (see fig. 7a), which can be simplified to a two-dimensional 3, 6-linked topology, in which R and S configuration secondary building units are arranged alternately (see fig. 7 b); a zagzig coordination polymer chain (shown in figure 8a) is constructed by bridging metal ions Cd1 and Cd2 by using nanoscale N-ligand bpep, wherein the included angle of Cd1-Cd2-Cd1 is 120.7 degrees, and the distance of Cd 1. cndot. Cd2 is about 2.0 nm; further, zagzig polymer chains are interwoven into a two-dimensional network topology (see fig. 8 b). Finally, N, O-ligands bridge trinuclear clusters, further building 3, 10-linked three-dimensional cross-pillared coordination polymer networks (see FIG. 9). The above mentioned features are the fluorescence properties of the supramolecular polymer CdOSP of the invention and the structural basis for further applications.

The solid state fluorescence spectra of the starting material and supramolecular polymer crystal samples were measured at room temperature (fig. 4 and 5, abscissa-wavelength, ordinate-fluorescence intensity). Analysis of the data in FIG. 4 shows that the strongest emission peak for the feedstock bpep is around 523nm under 419nm UV excitation. FIG. 5 shows the data analysis that under the excitation of 414nm visible light, the strongest emission peak wavelength of the CdOSP crystal sample at room temperature is 476nm, one shoulder peak is respectively arranged at 450nm and 506nm, the blue fluorescence emission wavelength range is 424-800nm, the Stokes shift is 62nm (the difference between the emission peak wavelength and the excitation peak wavelength) and the raw material bpep fluorescence emission peak wavelength (lambda)_em523nm), an approximately 47nm blue shift occurred. The study on the structure of bpep in supramolecular polymers shows that the dihedral angle between pyridine ring (N4) and C (C80) is about 18 °, the dihedral angle between C (C80) and benzene ring (C74) is about 17 °, and the dihedral angle between two benzene rings (C74, C65) is about 41 °, so that the pi-pi conjugation between bpep groups is reduced, the energy difference between molecular orbitals is increased, and the wavelength of fluorescence emitted after electron transition is shortened, i.e. blue shift.

In addition, the water solution of the fluorescent polymer prepared by the invention has the strongest emission peak wavelength at 476nm (the emission wavelength range is 400-800nm) in the visible light region and also emits blue fluorescence (FIG. 10). The good fluorescence property shows 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 mass of the actually obtained CdOSP is kept between 5.2 and 7.8mg based on m-H₃Calculated by bpt, the yield is 18.1% -27.1%. It was found that the low dissolution of bpep in polar solvents is a major factor affecting the yield.

Example 2

Taking the following materials according to the specific mass or volume: m-H₃bpt(10.0mg，0.035mmol)，bpep(12.53mg，0.035mmol)，Cd(NO₃)₂·4H₂O(16.04mg，0.052mmol)，CH₃CN(7mL)，H₂O(3mL)，HNO₃Solution (40. mu.L, 7mol/L, 0.28 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 blast air oven, heating to 160 ℃, reacting for 4 days, naturally cooling to room temperature to obtain an irregular crystal sample, filtering the irregular crystal sample from mother liquor, washing with distilled water, and naturally drying in the air at room temperature.

The product was characterized by X-ray diffraction (see FIG. 1), 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 high.

The embodiment is repeated for multiple times, and the mass of the actually obtained CdOSP is kept between 5.0 and 7.2mg based on m-H₃Calculated in bpt, yields ranged from 17.4% to 25.1%.

Example 3

Taking the following materials according to the specific mass or volume: m-H₃bpt(10.0mg,0.035mmol)，bpep(12.53mg,0.035mmol)，Cd(NO₃)₂·4H₂O(16.04mg，0.052mmol)，CH₃CN(7mL)，H₂O(3mL),HNO₃Solution (35. mu.L, 7mol/L,0.245 mmol). Placing the above materials in 25mL polytetrafluoroethylene lining, stirring for about 30min, sealing in a stainless steel reaction kettle, placing the reaction kettle in an electric heating air blast oven, heating to 150 deg.C, reacting for 5 days, Naturally cooling to room temperature to obtain irregular crystal sample, filtering from mother liquid, washing with distilled water, and naturally drying in air at room temperature.

The product was characterized by X-ray diffraction (see FIG. 1), 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 high.

The embodiment is repeated for multiple times, and the mass of the actually obtained CdOSP is kept between 5.8 and 8.6mg based on m-H₃Calculated by bpt, the yield is 20.2% -29.9%.

Second, the initial application of the supramolecular polymer of the invention

Example 4 fluorescence detection of anions

In view of the good luminescence property of the newly prepared supramolecular polymer CdOSP in aqueous solution, the selective fluorescence sensing detection of the supramolecular polymer CdOSP as an anion is researched. Preparing a supermolecule polymer CdOSP 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 code. Respectively measuring 0.5mL Br by using a pipette^-、WO₄ ^2-、MoO₄ ^2-、Cl^-、HCOO^-、NO2-、CO₃ ^2-、CH₃COO^-、I^-Aqueous sodium salt 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 anion solutions were measured by FLS1000 edinburgh fluorescence spectrometer, respectively, under excitation of light with a wavelength of 370 nm. From FIG. 10 (abscissa-wavelength; ordinate-fluorescence intensity), it can be seen that the luminescence intensity of the supramolecular polymer CdOSP suspension varies with the anion. Comparison of luminescence data of the supramolecular polymer CdOSP suspension revealed Br^-、WO₄ ^2-、MoO₄ ^2-、Cl^-、HCOO^-The fluorescence of the CdOSP suspension has different courses for NO 2-ion pairEnhancing the degree; in contrast, CO₃ ^2-、CH₃COO^-、I^-The ions have different degrees of quenching effect on the fluorescence of the CdOSP suspension, wherein I is added^-The ions make the fluorescence quenching effect of the CdOSP suspension most obvious. As can be seen from FIG. 11 (abscissa-anion species; ordinate-relative fluorescence intensity), the luminescence intensity of the CdOSP suspension (without anion) is represented by I^-The ion was quenched to about 78.7%.

To further explore pair I^-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). Separately, 2.5. mu.L-500. mu.L of aqueous sodium iodide solution (concentration of 0.01 mol. L) was measured by using a 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 I ^-The concentration of the solution to be detected is 10 mu M-2000 mu M respectively, and the sample without salt is used as a reference solution.

In accordance with the same conditions I was investigated^-Ion concentration versus luminescence intensity of the CdOSP suspension. From FIG. 12 (abscissa-wavelength; ordinate-fluorescence intensity), it can be seen that the emission intensity of the supramolecular polymer suspension is a function of I^-The ion concentration increased from 0 to 2000 μ M and decreased. By using the linear Stern-Volmer (S-V) equation: i is₀/I＝K_SV×[I^-]+1，(I₀And I represents the fluorescence intensity of the supramolecular polymer before and after addition of the analyte, K_SVRepresenting the quenching constant), the supramolecular polymer pair I was further analyzed^-The efficiency of the fluorescence fragmentation of the ions. FIG. 13 (abscissa-concentration; ordinate-I)₀I-1) analysis of the data shows that when I^-When the ion concentration is increased from 0. mu.M to 80. mu.M, the fluorescence intensity shows a good linear dependence (R)²0.99302). Through calculation: i is^-K of ion_SVThe value was 1.97X 10³M^-1. The results show that the novel organic supramolecular polymers are useful for I^-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. A supramolecular polymer containing two-axis chiral structures is characterized in that the chemical general formula is { [ Cd ]₃(m-bpt)₂(bpep)₂](H₂O)}_nBelongs to monoclinic system, space group is Pc, cell parameter

In the chemical formula, the component m-bpt^3-Is a rigid triorganocarboxylic acid m-H₃bpt is obtained by eliminating 3 protons, the m-H₃The bpt structure is shown as formula I; the structure of the component bpep is shown as a formula II,

2. supramolecular polymer with two-axis chiral structures according to claim 1, characterized by the fact that it comprises 3 crystallographically independent Cd in asymmetric units²⁺Ion, 2 m-bpt^3-2 bpep components and 1 lattice water molecule; each of the m-bpt^3-And 6 Cd²⁺Ion coordination, simplified into a 3-connected secondary structural unit, with the coordination mode shown in formula III, wherein m-bpt^3-With Cd²⁺Two mirror symmetry coordination modes are formed after ion coordination, and the two mirror symmetry coordination modes are respectively in R and S configurations; component bpep coordination bridged Cd²⁺Ions, as shown in formula IV; the Cd²⁺The coordination mode of the ions is shown as a formula V, and [ Cd ] is formed by sharing carboxylate radical₃N₄(CO₂)₆]Reduced to 10-linked secondary building blocks; the atomic number symbols in the formulas III to V represent the numbers of atoms in the asymmetric units, the upper right corner of the numbers is marked with a crystal engineering symmetry conversion symbol,

3. A process for the preparation of supramolecular polymers with two chiral axes as claimed in claims 1 or 2, characterized in that said polymers are present in the form of m-H₃bpt、bpep、Cd(NO₃)₂·4H₂O and HNO₃The raw material is prepared by a solvent thermal synthesis method by using a mixed solution of acetonitrile and water as a solvent.

4. The method for preparing supramolecular polymer with chiral structures of two axes as claimed in claim 3, characterized in that said solvothermal synthesis method 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 materials m-H₃bpt：bpep：Cd(NO₃)₂·4H₂O：HNO₃The mass ratio of (a) to (b) is 1: 1: 1.5: 6-8; the volume ratio of the solvents acetonitrile and water is 7: 3;

(2) and (3) stirring the reaction system at room temperature for 10-30 min, sealing the polytetrafluoroethylene lining in a steel sleeve, placing the steel sleeve in a constant-temperature air-blast oven, heating the temperature in the oven to 140-160 ℃, reacting for 3-5 days, and then naturally cooling, filtering and drying to obtain irregular-shaped crystals.

5. Process for the preparation of supramolecular polymers with two chiral axes as claimed in claim 4, characterized in that m-H in step (1)₃bpt：bpep：Cd(NO₃)₂·4H₂O：HNO₃The mass ratio of (1): 1: 1.5: 7.

6. method for the preparation of supramolecular polymers with two chiral axes as claimed in claim 4, characterized in that m-H in said reaction system ₃The initial mass concentration of bpt or bpep was 3.5 mmol/L.

7. The method for preparing supramolecular polymers with two chiral axes as claimed in claim 4, wherein the reaction temperature in step (2) is 150 ℃, and the drying is natural drying in air at room temperature after the crystal is washed with distilled water.

8. The application of the supramolecular polymer containing two axial chiral structures is characterized in that the supramolecular polymer prepared by the method of any one of claims 3 to 7 is applied to preparation of fluorescent materials and devices and identification of iodide ions.