A column-based[5]arene bicyclic molecule, its synthesis and its application in the detection of dichromate ions.

Abstract

This invention provides a column[5]arene-based bicyclic molecule that can detect dichromate ions with high selectivity and high sensitivity through enrichment effect. The column[5]arene-based bicyclic chemical sensor BPN1 was obtained by reacting bis-N-(2-aminoethyl)-2-(hexamyl)acetamide-functionalized column[5]arene with 1,4,5,8-naphthalenetetracarboxylic anhydride in DMF solution. The DMSO-H2O solution of the bicyclic chemical sensor BPN1 showed fluorescence at 455 nm, and the addition of Cr2O7... 2‑ The addition of other ions to the aqueous solution of BPN1 can induce fluorescence quenching, while the fluorescence of BPN1 does not change significantly upon the addition of other ions. Therefore, the dual macrocyclic chemical sensor BPN1 enables the detection of Cr2O7. 2‑ Single-selective recognition. Fluorescent titration experiments showed that this sensor molecularly recognizes Cr2O7. 2‑ It has high sensitivity.

Description

Technical Field

[0001] This invention relates to a method capable of highly sensitive and single-selective identification of Cr2O7. 2- The invention also relates to a method for synthesizing the bicyclic macrocyclic chemical sensor BPN1; and further relates to the fluorescence recognition of Cr2O7 by the bicyclic macrocyclic chemical sensor BPN1 in DMSO-H2O solution. 2- Its applications fall under the fields of chemical synthesis and ion detection. Background Technology

[0002] As is well known, heavy metal ion pollution is one of the most serious environmental problems, posing a significant threat to the survival of organisms. For example, Cr(VI) and its dichromate ions (Cr₂O₇) are particularly problematic. 2- Anions such as Cr(VI) are widely used in chemical engineering fields such as metallurgy, metal electroplating, and pigments, while Cr(VI) is characterized by high toxicity and carcinogenicity. Furthermore, due to the presence of dichromates (Cr2O7... 2- Cr(VI) is the most common source of Cr, therefore, a method for efficiently binding Cr2O7 is being developed. 2- A novel host to improve Cr2O7 2- The detection sensitivity and selectivity of macrocyclic chemistry or its ion pairs are crucial. Notably, the rapid development of macrocyclic chemistry has provided ample opportunities to improve sensing sensitivity and selectivity.

[0003] Novel macrocyclic host molecules have been a research hotspot in supramolecular chemistry due to their wide applications in sensors, self-assembled materials, and molecular machines. To date, many macrocyclic host molecules, including crown ethers, cyclodextrins, calixarenes, cucurbiturils, and columnar aromatics, have been successfully developed and widely used. However, the demand for novel macrocyclic hosts to provide more precise and efficient binding to various target guests to achieve specific functions remains significant. To address this urgent need, the scientific community has made various efforts in different ways, including modifying existing macrocycles and developing new macrocycles to achieve precise binding to target guests. All these methods have their own advantages, and fused bicyclic host molecules can provide two macrocyclic cavities to complex target guests. Furthermore, the two macrocycles of a fused bicyclic host molecule can provide an enrichment effect through the synergistic effect of the two cavities, enabling the binding of more complex guests or the construction of more complex supramolecular functional systems. Therefore, developing a novel fused bicyclic host molecule and studying its host-guest interaction characteristics in depth is very interesting and important.

[0004] This invention designs and synthesizes a novel column-[5]arene-based bicyclic chemical sensor molecule, BPN1. In BPN1, the methoxy group on the column[5]arene column can be Cr2O7. 2- It provides multiple hydrogen bonding sites and is expected to interact with Cr2O7. 2-Complexation occurs. Furthermore, the side ring formed by the flexible chain of a phenyl group of a columnar aromatic hydrocarbon using naphthalimide (NDI) also possesses abundant supramolecular interaction sites, allowing it to interact with Cr2O7. 2- Therefore, a fused bicyclic host molecule BPN1 can bind multiple Cr2O7 molecules. 2- This is an enrichment effect that can improve the detection of Cr2O7. 2- Sensitivity. Summary of the Invention

[0005] The purpose of this invention is to synthesize a bicyclic macrocyclic molecule based on column[5] aromatics that can provide two macrocyclic cavities, and to provide its synthesis method;

[0006] Another objective of this invention is to provide a highly sensitive and selective recognition of Cr2O7 by the bicyclic molecule through an enrichment effect. 2- Applications.

[0007] I. Bicyclic Chemical Sensor BPN1 and its Synthesis

[0008] The synthesis method of the bicyclic chemical sensor BPN1 of the present invention includes the following steps:

[0009] (1) Synthesis of ethyl thioethyl functionalized column[5] aromatic BAP: K2CO3 and ethyl mercaptoethyl were added to the acetonitrile solution of KI in the bromo[5] aromatic column. Under nitrogen protection, the reaction was carried out at 65~75℃ for 20~25h. The crude product was obtained by drying and volatilization, and pure ethyl thioethyl functionalized column[5] aromatic BAP was obtained by column chromatography.

[0010] The molar ratio of ethyl mercaptoacetate to brominated[5]arene is 2:1; the molar ratio of K2CO3 to ethyl mercaptoacetate is 1:1 to 1:2; and the molar ratio of brominated[5]arene to KI is 1:2 to 1:3.

[0011] (2) Synthesis of bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5] aromatics MP5: Ethylenediamine and ethyl thioacetate functionalized column[5] aromatics BAP were added to ethanol and reacted at 55~65℃ for 20~25 hours. The solvent was removed, filtered and dried to obtain bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5] aromatics MP5; wherein, the molar volume ratio of ethyl thioacetate functionalized column[5] aromatics to ethylenediamine was 0.5~1 mmol / mL.

[0012] (3) The bis-N-(2-aminoethyl)-2-(hexylthio)acetamide-functionalized column[5]arene was added dropwise to a DMF solution of 1,4,5,8-naphthalenetetracarboxylic anhydride, and acetic acid was added to catalyze the reaction. The reaction was carried out at 115~125°C for 45~50 h. The solvent was removed to obtain a brown crude product, which was then recrystallized with dichloromethane to obtain pure column[5]arene-based bicyclic molecule BPN1. The molar ratio of bis-N-(2-aminoethyl)-2-(hexylthio)acetamide-functionalized column[5]arene to 1,4,5,8-naphthalenetetracarboxylic anhydride was 1.2:1~1.3:1.

[0013] The molecular formula of the synthesized bicyclic chemical sensor BPN1 is: C 77 H 86 N4O 16 S2, labeled as BPN1, has the following structural formula:

[0014] .

[0015] The mass and proton spectra of the bicyclic chemical sensor molecule BPN1 are shown in [reference needed]. Figure 1 and Figure 2 .

[0016] II. Applications of the dual macrocyclic chemical sensor for the detection of molecular BPN1

[0017] 1. Fluorescence properties of the bicyclic chemical sensor molecule BPN1

[0018] Studies on the fluorescence performance of the bicyclic chemical sensor BPN1 show that it has good solubility in DMSO-H2O solution (DMSO volume percentage 90%). When the excitation wavelength is 360 nm, the sensor molecule BPN1 exhibits good fluorescence (emission wavelength 425 nm).

[0019] 2. The BPN1 molecule, a dual macrocyclic chemical sensor, fluorescently recognizes Cr2O7. 2-

[0020] In a DMSO-H2O solution (V) of the bicyclic chemical sensor molecule BPN1. DMSO V 水 In a 9:1 ratio, 0.1 M of Cr2O7 was added in a 10-fold equivalent (of the bicyclic chemical sensor molecule BPN1). 2- An aqueous solution of Cr2O7 was used to observe the fluorescence changes in the solution. The results showed that Cr2O7... 2- The addition of [a specific ion] quenches the fluorescence of the bicyclic chemical sensor molecule BPN1 in DMSO-H2O solution. Similarly, the addition of other ions (F [a specific ion]) quenches the fluorescence. - , Cl - , Br - , I- NO3 - ClO3 - IO3 - SO4 2- CO3 2- ClO4 - MnO4 2- SCN - CrO4 2- AsO2 - H2AsO4 - The fluorescence of the bicyclic chemical sensor molecule BPN1 in DMSO-H2O solution remained essentially unchanged. Figure 3 The fluorescence spectra (λ) of the bicyclic chemical sensor molecule BPN1 in the present invention after adding different ions to a DMSO-H2O solution are shown. ex =360 nm). The addition of other ions did not cause a significant change in the fluorescence of the bicyclic chemical sensor molecule BPN1 in DMSO-H2O solution, indicating that the bicyclic chemical sensor molecule BPN1 is sensitive to Cr2O7. 2- It has single-selection recognition capabilities.

[0021] Fluorescent titration experiments showed that the bicyclic chemical sensor molecule BPN1 is effective against Cr2O7. 2- The lowest detection limit is 1.27 × 10⁻⁶. -7 M (as) Figure 5 , 6 As shown in the figure, this illustrates that the bicyclic chemical sensor molecule BPN1 recognizes Cr2O7. 2- It has high sensitivity.

[0022] Meanwhile, in order to study the effects of other ions on the recognition of Cr2O7 by the bicyclic chemical sensor molecule BPN1, 2- To mitigate interference, we conducted an anti-interference experiment. Figure 4 Adding Cr2O7 to the DMSO-H2O solution of the bicyclic chemical sensor molecule BPN1 2- Based on this, anti-interference maps for different ions were added. The results show that the presence of other ions affects the recognition of Cr2O7 by the bicyclic chemical sensor molecule BPN1. 2- No obvious interference (e.g.) Figure 4 (As shown).

[0023] 3. Identification Mechanism Analysis

[0024] The recognition of Cr2O7 by the bimacrocyclic chemical sensor molecule BPN1 was investigated using 1H NMR spectroscopy. 2- The mechanism. In DMSO-H2O solution, the DMSO-... d6 Add 0.02, 0.5, and 1.0 equivalents of Cr2O7 to the solution, respectively. 2- Then, observe the changes in the hydrogen NMR spectrum peaks. Figure 7 The DMSO- of BPN1, the dual macrocyclic chemical sensor molecule of this invention. d 6 Different equivalents of Cr2O7 were added to the solution 2- The proton NMR spectrum. From Figure 7 It can be seen that with Cr2O7 2- The addition of H2 and H4 in the columnar aromatic cavity causes them to shift to a higher field, indicating that the bicyclic chemical sensor molecule BPN1 interacts with Cr2O7. 2- Hydrogen bonding occurs. The high-field shift in the side ring H3 indicates that the naphthalene group on the side ring interacts with Cr2O7. 2- An anion-π interaction occurs, causing the bicyclic chemical sensor molecule BPN1 to interact with Cr2O7. 2- To form a complex, Cr2O7 was added. 2- Subsequently, the fluorescence of the bicyclic chemical sensor molecule BPN1 was quenched.

[0025] In addition, to visually demonstrate multiple supramolecular interactions, non-covalent interaction maps were obtained using the IGM method. Two guest molecules were treated as fragments, and the host molecule as another fragment, and IGM analysis was performed. The resulting green δg isosurfaces highlight the interaction regions between the corresponding fragments. Figure 8 NCI analysis can provide detail to distinguish different weak non-covalent interactions, such as van der Waals forces, hydrogen bonds, and steric repulsion, and quantitatively describe their strength. These green patches are visualizations of BPN1 and Cr2O7. 2- Interactions between the components, such as anion-π interactions and multiple hydrogen bonds. These results demonstrate that the enrichment effect between the BPN1 bicyclic rings can achieve its enrichment of Cr2O7. 2- The high sensitivity of the identification also proves the feasibility of our proposal to introduce an "enrichment effect" into the design of chemical sensors to enhance host-guest interactions.

[0026] In summary, this invention designs and synthesizes a novel column[5]arene-based bicyclic molecule that can detect dichromate ions with high selectivity and high sensitivity through enrichment effect. The column[5]arene MP5 was functionalized with bis-N-(2-aminoethyl)-2-(hexamyl)acetamide and reacted with 1,4,5,8-naphthalenetetracarboxylic anhydride in DMF solution to obtain the column[5]arene-based bicyclic chemical sensor BPN1. The DMSO-H2O solution of the bicyclic chemical sensor BPN1 showed fluorescence at 455 nm, and the addition of Cr2O7... 2-The addition of other ions, such as F, can cause fluorescence quenching in the bicyclic chemical sensor BPN1. - , Cl - ,Br - , I - NO3 - ClO3 - IO3 - SO4 2- CO3 2- ClO4 - MnO4 2- SCN - CrO4 2- AsO2 - H2AsO4 - Afterwards, the fluorescence of the dual macrocyclic chemical sensor BPN1 did not change significantly, therefore the dual macrocyclic chemical sensor BPN1 achieved the detection of Cr2O7. 2- Single-selective recognition. Fluorescent titration experiments showed that the bicyclic chemical sensor molecule BPN1 selectively recognizes Cr2O7. 2- The lowest detection limit is 1.27 × 10⁻⁶. -7 M indicates that the bicyclic chemical sensor molecule BPN1 recognizes Cr2O7. 2- It exhibits high sensitivity. Furthermore, anti-interference experiments show that adding other ions to the aqueous solution does not interfere with the recognition process. The recognition of Cr2O7 by BPN1 was investigated experimentally and using density functional theory (DFT). 2- The mechanism revealed that BPN1 can bind to Cr2O7 through various weak interactions, including hydrogen bonds and anion-π interactions. 2- Cr2O7 was achieved 2- High sensitivity and selectivity of detection. Therefore, a fused bicyclic host molecule BPN1 can simultaneously bind multiple Cr2O7 molecules. 2- This is an enrichment effect, which can improve the detection of Cr2O7. 2- Sensitivity. Attached Figure Description

[0027] Figure 1 This is the mass spectrum of BPN1, the dual macrocyclic chemical sensor molecule of this invention;

[0028] Figure 2 The hydrogen spectrum of BPN1, the dual macrocyclic chemical sensor molecule of this invention;

[0029] Figure 3 The full scan (λ) of the DMSO-H2O solution of the dual macrocyclic chemical sensor molecule BPN1 of this invention was performed by adding different ions respectively. ex =360 nm);

[0030] Figure 4 Cr2O7 was added to the DMSO-H2O solution of the bicyclic chemical sensor molecule BPN1 of this invention. 2- Then, anti-interference diagrams for other ions are added separately;

[0031] Figure 5 Cr2O7 was added to the DMSO-H2O solution of the bicyclic chemical sensor molecule BPN1 of this invention. 2- The fluorescence titration diagram;

[0032] Figure 6 Cr2O7 was added to the DMSO-H2O solution of the bicyclic chemical sensor molecule BPN1 of this invention. 2- The lowest detection limit;

[0033] Figure 7 The DMSO- of BPN1, the dual macrocyclic chemical sensor molecule of this invention. d 6 Different equivalents of Cr2O7 were added to the solution 2- The proton NMR titration spectrum;

[0034] Figure 8 The present invention relates to the dual macrocyclic chemical sensor molecules BPN1 and Cr2O7. 2- Weak interaction force diagram between them;

[0035] Figure 9 The hydrogen spectrum of BAP;

[0036] Figure 10 The hydrogen spectrum of MP5; Detailed Implementation

[0037] The preparation of the bicyclic chemical sensor molecule BPN1 and its fluorescence recognition of Cr2O7 according to specific embodiments of the present invention are described below. 2- The application will be further explained.

[0038] Example 1: BPN1, a dual macrocyclic chemical sensor molecule

[0039] (1) Synthesis of ethyl thioethyl functionalized column[5] aromatic BAP: K2CO3 (0.55 g, 4 mmol) and ethyl mercaptoethyl (0.48 g, 4 mmol) were added to a solution of bromo[5] aromatic P5 (2.09 g, 2 mmol), KI (1.11 g, 6 mol) in acetonitrile (250 ml). Under nitrogen protection, the mixture was heated (100 °C) for 24 h in a round-bottom flask, dried and volatilized to obtain the crude product. The crude product was separated by ethyl acetate / petroleum ether (v / v 1:10) column chromatography to obtain a white solid (62%). The 1H NMR spectrum of BAP is shown in the figure. Figure 9 ;

[0040] The synthesis method of brominated columnar aromatic P5 is described in reference Q. Lin, Y.-Q. Fan, P.-P. Mao, L. Liu, et al., Pillar[5]arene-Based Supramolecular Organic Framework with Multi-Guest Detection and Recyclable Separation Properties. Chem. Eur. J. 2018, 24, 777-783.

[0041] (2) Synthesis of bis-N-(2-aminoethyl)-2-(hexamyl)acetamide-functionalized column[5] aromatics MP5: Ethylenediamine (2 mL) and ethyl thioester-functionalized column[5] aromatics BAP (1.15 g, 1 mmol) were reacted in ethanol (250 mL). The mixture was heated (80 °C) in a round-bottom flask for 24 hours to remove the solvent. After filtration and drying, MP5 was obtained as a white solid with a content of 0.91 g, accounting for 89%. The 1H NMR spectrum of MP5 is shown in the figure. Figure 10 .

[0042] (3) Synthesis of the bicyclic chemical sensor molecule BPN1: Bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5]arene MP5 (0.14 g, 0.12 mmol) was added dropwise to 1,4,5,8-naphthalenetetracarboxylic anhydride (0.027 g, 0.10 mmol) dissolved in DMF (250 mL) to synthesize column[5]arene-based bicyclic chemical sensor BPN1. Acetic acid was added to catalyze the reaction, and the reaction was carried out at 120°C for 48 h. The solvent was removed to obtain a brown crude product, which was then recrystallized from dichloromethane to obtain pure BPN1 (0.03 g, 19%).

[0043] The synthesis route is as follows:

[0044]

[0045] Example 2: BPN1, a dual macrocyclic chemical sensor molecule, recognizes Cr2O7. 2-

[0046] Transfer 2 mL of a DMSO-H2O solution of the bicyclic chemical sensor molecule BPN1 (C BPN1 =1×10 -5 M,V DMSO V 水 =9:1) was added to a series of colorimetric tubes, and a series of ions (F) were added to each tube. - , Cl - , Br - , I- NO3 - ClO3 - IO3 - SO4 2- CO3 2- ClO4 - MnO4 2- SCN - Cr2O7 2- CrO4 2- AsO2 - H2AsO4 - If the fluorescence of the sensor molecules in the DMSO-H2O solution is quenched in an aqueous solution (C=0.1M), it indicates that Cr2O7 has been added. 2- If the fluorescence intensity of the sensor molecules does not change, it indicates that Cr2O7 was not added. 2- .

Claims

1. A bicyclic molecule based on columnar[5] aromatics, with the molecular formula C 77 H 86 N4O 16 S2, the structural formula is: 。 2. The method for synthesizing bimacrocyclic molecules based on columnar [5] aromatics as described in claim 1, comprising the following steps: (1) Add K2CO3 and ethyl mercaptoacetate to the acetonitrile solution of KI in the brominated column[5] aromatics, react at 90~100℃ for 20~25h under nitrogen protection, dry and volatilize to obtain crude product, and separate by column chromatography to obtain ethyl thioethyl functionalized column[5] aromatics; The structural formula of brominated aromatic hydrocarbons[5] is: The structural formula of the aromatic hydrocarbon functionalized column of ethyl thioester [5] is: (2) Add ethylenediamine and ethyl thioethyl to ethanol and react at 60-80°C for 20-25 hours. Remove the solvent, filter and dry to obtain bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5] aromatics; The structural formula of the bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5] aromatic hydrocarbon is: (3) The bis-N-(2-aminoethyl)-2-(hexamyl)acetamide functionalized column[5] aromatics were added dropwise into a DMF solution of 1,4,5,8-naphthalenetetracarboxylic anhydride, and acetic acid was added to catalyze the reaction. The reaction was carried out at 115~125°C for 45~50 h. The solvent was removed to obtain a brown crude product, which was then recrystallized with dichloromethane to obtain a pure column[5] aromatic bicyclic molecule.

3. The method for synthesizing bimacrocyclic molecules based on columnar [5] aromatics as described in claim 2, characterized in that: In step (1), the molar ratio of ethyl mercaptoacetate to brominated[5]arene is 2:1; the molar ratio of K2CO3 to ethyl mercaptoacetate is 1:1 to 1:2; and the molar ratio of brominated[5]arene to KI is 1:2 to 1:

3.

4. The method for synthesizing bimacrocyclic molecules based on columnar aromatics as described in claim 2, characterized in that: In step (2), the molar volume ratio of aromatic hydrocarbons to ethylenediamine in the ethyl thioethyl ester functionalized column [5] is 0.5~1 mmol / mL.

5. The method for synthesizing bimacrocyclic molecules based on columnar [5] aromatics as described in claim 2, characterized in that: In step (3), the molar ratio of bis-N-(2-aminoethyl)-2-(hexylthio)acetamide-functionalized column[5] aromatic hydrocarbon and 1,4,5,8-naphthalenetetracarboxylic anhydride is 1.2:1~1.3:

1.

6. As described in claim 1, the columnar[5]arene-based bicyclic molecule is used as a chemical sensor molecule for non-disease diagnosis and treatment purposes in the fluorescence detection of Cr2O7. 2- Applications in [the field].

7. As described in claim 6, the column-based [5] aromatic bicyclic molecule is used as a chemical sensor molecule for non-disease diagnosis and treatment purposes in the fluorescence detection of Cr2O7. 2- The application of this technology is characterized by: In a DMSO-H2O solution based on columnar[5] aromatic bicyclic molecules, Cr2O7 was added respectively. 2- ,F - , Cl - , Br - , I - NO3 - ClO3 - IO3 - SO4 2- CO3 2- ClO4 - MnO4 2- SCN - CrO4 2- AsO2 - Only by adding Cr2O7 2- It can quench the fluorescence of DMSO-H2O solution containing bicyclic aromatic molecules of column[5].

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