Series of chiral Ir (III) metal complexes for anion recognition and preparation method of chiral Ir (III) metal complexes

Abstract

The invention discloses a series of chiral Ir (III) metal complexes for anion recognition and a preparation method thereof, and belongs to the technical field of medicine synthesis. Firstly, a chiral iridium complex building module is obtained through a series of reactions, and then the chiral iridium complex building module reacts with chiral cyclohexanediamine D1 or D2 to synthesize a series of chiral Ir (III) metal complex structures. According to the series of chiral Ir (III) metal complex structures, the delta / lambda spiral chirality of the metal center Ir (III) and the S / R inherent chirality of cyclohexanediamine are combined, so that various multi-dimensional stereo chemical microenvironments are constructed, and accurate regulation and control of a hydrogen bond network and space adaptation in the anion recognition process are realized; the problems that a traditional receptor is difficult to distinguish specific-configuration anions and the recognition efficiency is low in a complex medium are solved. A nuclear magnetic titration experiment and an isothermal titration calorimetry prove that the chiral metal complex has excellent sulfate radical specific selective recognition capability.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of a series of chiral Ir(III) metal complexes, belonging to the field of pharmaceutical synthesis. Background Art

[0002] Anions play an irreplaceable role in fields such as biological metabolism, environmental monitoring, disease diagnosis, and industrial catalysis. For example, excessive intake of fluoride ions (F ⁻ -) may lead to skeletal lesions, abnormal accumulation of phosphate (PO4 3- -) is associated with chronic kidney disease, sulfate (SO4 2- -) can be used to improve alkaline soil and remove heavy metal ions from wastewater, while nitrate (NO3 - -) is a key pollutant for water eutrophication. Therefore, the development of highly selective and sensitive anion recognition technologies is of great significance for achieving precise detection, environmental governance, and early disease intervention. However, anion recognition is a fundamental problem in chemical research, mainly limited by its inherent characteristics: (1) The strong solvation effect weakens the binding ability between the receptor and the anion; (2) The large ionic radius and low charge density result in dispersed forces; (3) The complex configuration (such as tetrahedron, planar triangle) requires the receptor to have precise spatial matching. These characteristics hinder the formation of stable covalent bonds, forcing the recognition process to rely on supramolecular host-guest non-covalent interactions, including electrostatic interactions, hydrogen bonds, hydrophobic effects, Lewis acid-base coordination, and anion-π interactions. Therefore, the diversity and complex chemical behavior of anions pose a huge challenge to their recognition, and there is an urgent need for innovative design of new recognition systems.

[0003] The aminothiourea group has become the core framework for anion receptor design due to its strong acidity (significant N-H acidity) and directional two-way hydrogen bonding ability. The thiourea unit within its molecule can form a high-affinity binding pocket through a pre-organized hydrogen bond network, such as the selective recognition of carboxylate and halide ions. However, existing receptors still face problems such as solvent interference and insufficient configurational adaptability, especially in complex systems, it is difficult to achieve selective recognition of anions with different stereoconfigurations. Transition metal Ir(III) complexes have been widely used in phosphorescence sensing, photocatalysis, and photodynamic therapy due to their excellent photophysical and chemical properties (such as long-lived phosphorescence, large Stokes shift, and photostability). However, existing research has mostly focused on the optical response performance of the complexes, while ignoring the potential of their chiral skeletons to actively regulate the recognition process. Summary of the Invention

[0004] Aiming at the technical defect that the influence of the stereochemical microenvironment on the anion recognition mechanism in the prior art is unclear, the purpose of the present invention is to provide a preparation method and application of a series of chiral Ir(III) metal complex structure compounds. This series of chiral cationic Ir(III) metal complex structures combine the Δ / Λ helical chirality of the metal center Ir(III) with the S / R inherent chirality of cyclohexanediamine to construct a variety of multi-dimensional stereochemical microenvironments, realizing the precise regulation of hydrogen bond networks and spatial adaptation during the anion recognition process, and solving the problems that traditional receptors are difficult to distinguish anions with specific configurations and have low recognition efficiency in complex media. The purpose of the present invention will be achieved through the following technical solutions: A class of chiral Ir(III) metal complex structures has the following structural formula: or ; Z is S or O, X - is an anion, X - is selected from Cl - 、Br - 、I - 、PF6 - 、NO3 - 、SO4 2- or CF3SO3 - ; is selected from the following structures: ; wherein, m is an integer from 1 to 5; Y - is an anion, when Y - is Cl - 、Br − 、I − 、PF6 - 、NO3 - 、or CF3SO3 - ,n is 2; when Y - is SO4 2- ,n is 1.

[0005] R is selected from the following structures: .

[0006] The preparation method of the series of chiral Ir(III) metal complex structure compounds, the compounds are obtained by reacting chiral Ir(III) complex building blocks M1 or M2 with diamines respectively; The chiral Ir(III) complex building blocks M1 and M2 are selected from the following structures:

[0007] The definition of the diamine is the same as that in the structural general formula; R' is -NCS or -NCO.

[0008] X - , Y - , n, m, are defined the same as in the structural general formula.

[0009] The described series of specific chiral Ir(III) metal complex structure compounds, which are divided into four different chiral structures: L1D1, L2D2, L1D2, and L2D1. The structures are as follows:

[0010] Among them, X - is an anion, and the anion is selected from Cl - , Br − , I − , PF6 - , NO3 - , SO4 2- or CF3SO3 - , and the whole metal complexes L1D1, L2D2, L1D2, and L2D1 are electrically neutral as a whole.

[0011] Specifically, when X - is PF6 - , the L1-D1 chiral structure is as follows:

[0012] The L2-D2 chiral structure is as follows:

[0013] The L1-D2 chiral structure is as follows:

[0014] The L2-D1 chiral structure is as follows:

[0015] The preparation method of the described series of chiral Ir(III) metal complex structure compounds, which is obtained by reacting the chiral metal Ir(III) complex building blocks L1 or L2 with the chiral diamine D1 or D2 respectively. The synthesis route is as follows: L1 + D1 → L1-D1; L2 + D2 → L2-D2; L1 + D2 → L1-D2; L2 + D1 → L2-D1.

[0016] The chiral Ir(III)-based complex building block L1 has the following structure:

[0017] The chiral Ir(III)-based complex building block L2 has the following structure:

[0018] Wherein, X - has the same definition as that in the above structures of L1D1, L2D2, L1D2, and L2D1.

[0019] Specifically, when X - is PF6 - the structure of the chiral Ir(III) complex building block is as follows:

[0020] The chiral diamine D1 is selected from (1S,2S)-1,2-cyclohexanediamine; The chiral diamine D2 is selected from (1R,2R)-1,2-cyclohexanediamine.

[0021] The preparation method specifically includes the following steps:

[0022] Step 1: Add raw materials 2-bromopyridine, 4-nitrophenylboronic acid, sodium carbonate, and PdCl2(dppf) at 90 °C, reflux in ethylene glycol monomethyl ether for 24 h under argon protection. After the reaction is completed, cool to room temperature, slowly pour the reaction solution into deionized water, perform suction filtration under reduced pressure, collect the filter cake, dry it, and perform silica gel column chromatography to obtain a pale yellow powder compound a (nitrophenylpyridine).

[0023]

[0024] Step 2: Add compound a and iridium trichloride at 120 °C, reflux in a mixed solvent of ethylene glycol monomethyl ether / water for 24 h under argon protection. After the reaction is completed, cool to room temperature, perform suction filtration under reduced pressure, wash with deionized water, collect the filter cake, dry it, and obtain a red powder product b.

[0025]

[0026] Step 3: Add raw material b, L-proline / D-proline, and sodium methoxide at 25 °C, react in methanol overnight under argon protection. After the reaction is completed, evaporate the solvent, wash with deionized water, dry it, perform suction filtration, and perform silica gel column chromatography to obtain a red solid product Δ-c or Λ-c.

[0027]

[0028] Step 4: Add raw material Δ-c or Λ-c, trifluoroacetic acid, ammonium hexafluorophosphate, and 2,2'-bipyridine at 25 °C, and react in dichloromethane for 24 h under argon protection. After the reaction is completed, evaporate the solvent to obtain the orange solid product Δ-d or Λ-d.

[0029]

[0030] Step 5: Add raw material Δ-d or Λ-d, 10% Pd / C, and hydrazine hydrate at 25 °C, and react in dichloromethane overnight. After the reaction is completed, filter through diatomaceous earth and evaporate the solvent to obtain the orange product Δ-e or Λ-e.

[0031]

[0032] Step 6: Add raw material Δ-e or Λ-e and 2,2'-thiocarbonyl diimidazole at 25 °C, and react in dichloromethane overnight under argon protection. After the reaction is completed, evaporate the solvent and perform silica gel column chromatography to obtain the yellow solid product L1 or L2.

[0033]

[0034] Step 7: Charge L1 or L2 and D1 or D2 according to a molar ratio of 1:6, add them to a certain volume of dichloromethane solution, react overnight at room temperature, and perform vacuum distillation to obtain the orange-yellow products L1-D1, L2-D2, L1-D2, and L2-D1.

[0035] Use of the compounds L1-D1, L2-D2, L1-D2, and L2-D1 for specifically and selectively recognizing sulfate ions in solution.

[0036] Evaluate the difference in the recognition ability of the compounds L1-D1, L2-D2, L1-D2, and L2-D1 for different anions in DMSO-d6 solution through nuclear magnetic titration experiments. The experimental results show that the above chiral metal complexes L1-D1, L2-D2, L1-D2, and L2-D1 exhibit differences in the recognition ability for different anions in DMSO-d6 solution, and the recognition ability is: SO4 2- >> HSO4 - >H2PO4 - > Cl - > Br - > I - = NO3 - = ClO4 - = BF4 - .

[0037] The beneficial effect of the present invention is: using a cationic Λ / Δ iridium coordination compound with a single chiral configuration (Λ-Ir-L pro, Δ-Ir-L pro ) module, a series of reactions were carried out to obtain a chiral iridium complex, which was then reacted with chiral cyclohexanediamine D1 or D2 to synthesize a series of chiral cationic Ir(III) metal complex structures. This series of chiral cationic Ir(III) metal complex structures combines the Δ / Λ helical chirality of the metal center Ir(III) with the S / R inherent chirality of cyclohexanediamine, constructing a variety of multi-dimensional stereochemical microenvironments, realizing the precise regulation of hydrogen bond networks and spatial adaptation in the anion recognition process, and solving the problems that traditional receptors are difficult to distinguish specific configuration anions and have low recognition efficiency in complex media. Nuclear magnetic titration experiments and isothermal titration calorimetry prove that this type of chiral metal complex has excellent sulfate-specific selective recognition ability, and in addition, it also shows different recognition modes for anions with different configurations.

[0038] Transition metal Ir(III) complexes have excellent photophysical and chemical properties. Their octahedral coordination configuration endows Δ / Λ helical chirality characteristics, and the stereochemical properties can be precisely regulated through ligand design. This chirality not only affects the luminescence behavior of the complex but also can act as a "stereochemical switch" to regulate intermolecular forces (such as hydrogen bond orientation and spatial adaptation), thereby constructing a dynamic recognition interface. Especially by integrating the Δ / Λ configuration with hydrogen bond donor groups such as thiosemicarbazide, and introducing controllable chiral centers, the spatial interaction mode between the receptor and the anion can be directionally regulated, thus breaking through the selectivity bottleneck of traditional recognition systems and achieving configuration-dependent anion selective recognition through the chiral microenvironment. Description of the Drawings

[0039] Figure 1 is the 1H NMR spectrum of metal complex L1.

[0040] Figure 2 is the 1H NMR spectrum of metal complex L2.

[0041] Figure 3 is the 1H NMR spectrum of metal complexes L1-D1 and L2-D2.

[0042] Figure 4 is the 1H NMR spectrum of metal complexes L1-D2 and L2-D1.

[0043] Figure 5 is the UV-Vis absorption spectrum of metal complexes L1-D1 and L2-D2.

[0044] Figure 6 is the UV-Vis absorption spectrum of metal complexes L1-D2 and L2-D1.

[0045] Figure 7 is the emission spectrum of metal complexes L1-D1 and L2-D2.

[0046] Figure 8 These are the emission spectra of the metal complexes L1-D2 and L2-D1.

[0047] Figure 9 These are the circular dichroism spectra of the metal complexes L1-D1 and L2-D2.

[0048] Figure 10 These are the circular dichroism spectra of the metal complexes L1-D2 and L2-D1. Detailed implementation manners

[0049] The present invention will be further described below in conjunction with specific embodiments.

[0050] Example 1

[0051] 1 mmol of 2-bromopyridine, 1 mmol of 4-nitrophenylboronic acid, and 0.03 mmol of PdCl2(dppf) were added in a molar ratio of 1:1:0.03. Under argon protection, ethylene glycol monomethyl ether was added, and then 10 ml of 2M sodium carbonate solution was added. The temperature was raised to 90 °C and refluxed for 24 h. After the reaction was completed, it was cooled to room temperature. The reaction solution was slowly poured into deionized water, filtered under reduced pressure, the filter cake was collected, dried, and purified by silica gel column chromatography to obtain a pale yellow powder product a with a yield of 87%.

[0052] 1 1H NMR (400 MHz, CDCl3): δ 8.75 (d, J J = 4.7 Hz, 1H), 8.33 (d, J J = 8.4Hz, 2H), 8.19 (d, J J = 8.1 Hz, 2H), 7.88 – 7.79 (m, 2H), 7.40 (t, J J = 5.5 Hz,1H).

[0053] Example 2

[0054]

[0055] 2.5 mmol of raw material a and 1 mmol of iridium trichloride were added in a molar ratio of 2.5:1. Under argon, a mixed solvent of ethylene glycol monomethyl ether / water (volume ratio 3 / 1) was added. The temperature was raised to 120 °C and refluxed for 24 h. After the reaction was completed, it was cooled to room temperature, filtered under reduced pressure, washed with deionized water, the filter cake was collected, dried, and a red powder product b with a yield of 70% was obtained.

[0056] 11H NMR (400 MHz, CD2Cl2): δ 9.27 (d, J J = 5.5 Hz, 1H), 8.18 (d, J J = 8.0 Hz, 1H), 8.11 – 8.06 (m, 1H), 7.78 (d, J J = 8.6 Hz, 1H), 7.72 (dd, J J = 8.5, 2.1 Hz, 1H), 7.15 – 7.11 (m, 1H), 6.64 (d, J J = 2.2 Hz, 1H).

[0057] Example 3

[0058]

[0059] At 25 °C, 1 mmol of raw material b, 2 mmol of L-proline (D-proline), and 1 mmol of sodium methoxide were added in a molar ratio of 1:2:1. The reaction was carried out overnight in methanol under argon protection. After the reaction was completed, the solvent was evaporated, washed with deionized water, dried, filtered by suction, and purified by silica gel column chromatography to obtain a red solid product Λ-c (Δ-c) with a yield of 80%.

[0060] Λ-c, 1 1H NMR (400 MHz, DMSO-d6): δ 9.18 (d, J J = 5.6 Hz, 1H), 8.79 (d, J J = 5.5 Hz, 1H), 8.51 (d, J J = 8.1 Hz, 1H), 8.45 (d, J J = 8.0 Hz, 1H), 8.25 – 8.14 (m, 2H), 8.08 (dd, J J = 19.7, 8.6 Hz, 2H), 7.81 – 7.61 (m, 4H), 7.03 (d, J J = 2.1 Hz, 1H), 6.59 (d, J J = 2.1 Hz, 1H), 6.22 (dd, J J = 14.6, 8.1 Hz, 1H), 3.89 (dd, J J = 14.9, 8.6 Hz, 1H), 2.19 (dd, J= 10.0, 5.1 Hz, 1H), 2.11 – 1.95(m, 1H), 1.79 (td, J = 14.2, 7.9 Hz, 1H), 1.58 – 1.45 (m, 1H), 1.45 – 1.33(m, 2H). Δ-c, 1 1H NMR (400 MHz, DMSO-d6): δ 8.84 (d, J = 5.2 Hz, 1H), 8.69 (d, J = 5.3 Hz, 1H), 8.51 (d, J = 8.0 Hz, 1H), 8.45 (d, J = 7.9 Hz, 1H), 8.27 –8.14 (m, 2H), 8.05 (t, J = 9.6Hz, 2H), 7.76 (s, 2H), 7.64 (d, J = 8.3 Hz,2H), 6.98 (s, 1H), 6.60 (s, 1H), 5.60 (d, J = 7.9 Hz, 1H), 3.70 (dd, J =17.5, 8.9 Hz, 1H), 3.03 (s, 1H), 2.76 (d, J = 8.8 Hz, 1H), 2.26 – 1.86 (m,3H), 1.70 (dd, J = 18.4, 9.0 Hz, 1H).

[0061] Example 4

[0062]

[0063] At 25 °C, 1 mmol of the raw material Δ-c(Λ-c), 1.1 mmol of 2,2'-bipyridine, 1 mmol of trifluoroacetic acid, and 10 mmol of ammonium hexafluorophosphate were added in a molar ratio of 1:1.1:1:10, and the reaction was carried out in methanol under argon protection for 24 h to obtain an orange solid product Δ-d(Λ-d) with a yield of 95%.

[0064] Δ-d, 1 1H NMR (400 MHz, DMSO-d6) : δ 8.93 (d, J = 8.2 Hz, 1H), 8.56 (d, J= 8.1 Hz, 1H), 8.33 (m, J = 8.1, 1.2 Hz, 1H), 8.27 (d, J = 8.7 Hz, 1H),8.22 – 8.11 (m, 1H), 7.94 (d, J = 5.0 Hz, 1H), 7.90 (dd, J = 8.6, 2.3 Hz,1H), 7.80 (d, J = 5.5 Hz, 1H), 7.67 (m, 1H), 7.42 (m, J = 9.8, 3.5 Hz, 1H),6.85 (d, J = 2.2 Hz, 1H). Λ-d, 1 1H NMR (400 MHz, DMSO-d6): δ 8.93 (d, J = 8.2 Hz, 1H), 8.57 (d, J = 8.1 Hz, 1H), 8.32 (m, J = 8.1, 1.2 Hz, 1H), 8.27 (d, J = 8.7 Hz, 1H),8.21 – 8.10 (m, 1H), 7.91 (d, J = 5.0 Hz, 1H), 7.89 (dd, J = 8.7, 2.3 Hz,1H), 7.80 (d, J = 5.5 Hz, 1H), 7.68 (m, 1H), 7.41 (m, J = 9.8, 3.5 Hz, 1H),6.86 (d, J = 2.2 Hz, 1H).

[0065] Example 5

[0066]

[0067] At 25 °C, 1 mmol of Δ-d(Λ-d), 1 mmol of 10% Pd / C, and 10 mmol of hydrazine hydrate were added in a molar ratio of 1:1:10, and the reaction was carried out overnight in dichloromethane. After the reaction was completed, it was filtered through diatomaceous earth, and the solvent was evaporated to obtain an orange product Δ-e(Λ-e) with a yield of 99%.

[0068] Λ-e, 11H NMR (400 MHz, DMSO-d6): δ 8.82 (d, J J = 8.2 Hz, 1H), 8.23 (td, J J = 8.0, 1.5 Hz, 1H), 7.98 (d, J J = 4.5 Hz, 1H), 7.84 (d, J J = 8.3 Hz, 1H), 7.74 – 7.65 (m, 2H), 7.56 (d, J J = 8.5 Hz, 1H), 7.30 (d, J J = 5.3 Hz, 1H), 6.85– 6.78 (m, 1H), 6.26 (dd, J J = 8.4, 2.1 Hz, 1H), 5.48 (d, J J = 2.1 Hz, 1H), 5.24 (s, 2H). Δ-e, 1 1H NMR (400 MHz, DMSO-d6): δ 8.82 (d, J J = 8.2 Hz, 1H), 8.23 (td, J J = 8.0, 1.5 Hz, 1H), 7.98 (d, J J = 4.5 Hz, 1H), 7.84 (d, J J = 8.3 Hz, 1H), 7.74 – 7.65 (m, 2H), 7.56 (d, J J = 8.5 Hz, 1H), 7.30 (d, J J = 5.3 Hz, 1H), 6.85– 6.78 (m, 1H), 6.26 (dd, J J = 8.4, 2.1 Hz, 1H), 5.48 (d, J J = 2.1 Hz, 1H), 5.24 (s, 2H).

[0069] Example 6

[0070]

[0071] At 25 °C, 1 mmol of Δ-e(Λ-e) and 1 mmol of 2,2'-thiocarbonyl diimidazole were added in a molar ratio of 1:1, and the reaction was carried out overnight in dichloromethane under argon protection. After the reaction was completed, the solvent was evaporated, and silica gel column chromatography was performed to obtain the yellow solid product L1 (L2) with a yield of 85%.

[0072] L1, 1 H NMR (400 MHz, CD2Cl2): δ 8.55 (d, J J = 8.2 Hz, 1H), 8.17 (dd, J J =11.2, 4.7 Hz, 1H), 8.06 – 7.92 (m, 2H), 7.92 – 7.82 (m, 1H), 7.76 (d, J J = 8.4Hz, 1H), 7.55 – 7.49 (m, 1H), 7.47 (d, J J = 5.8 Hz, 1H), 7.08 (ddd, J J = 7.4,5.8, 1.5 Hz, 1H), 7.05 – 6.93 (m, 1H), 6.08 (d, J J = 2.0 Hz, 1H). L2, 1 H NMR (400 MHz, CD2Cl2) : δ 8.55 (d, J J = 8.2 Hz, 1H), 8.17 (dd, J J = 11.2, 4.7 Hz, 1H), 8.06 – 7.92 (m, 2H), 7.92 – 7.82 (m, 1H), 7.76 (d, J J =8.4 Hz, 1H), 7.55 – 7.49 (m, 1H), 7.47 (d, J J = 5.8 Hz, 1H), 7.08 (ddd, J J =7.4, 5.8, 1.5 Hz, 1H), 7.05 – 6.93 (m, 1H), 6.08 (d, J J = 2.0 Hz, 1H).

[0073] Example 7

[0074]

[0075] At 25 °C, 1 mmol of raw material L1 and 6 mmol of (1S,2S)-1,2-cyclohexanediamine (D1) were added in a molar ratio of 1:6. The reaction was carried out overnight in dichloromethane under argon protection. After the reaction was completed, it was washed with ether and dried to obtain an orange-yellow solid product with a yield of 90%.

[0076] 1 H NMR (400 MHz, DMSO-d6): δ 9.44 (s, 1H, H17), 8.87 (d, J J = 7.8 Hz, 1H, H2), 8.27 (t, J J = 7.9 Hz, 1H, H3), 8.13 (d, J J = 8.3 Hz, 1H, H6), 8.01 (d, J J = 5.4 Hz, 1H, H5), 7.91 – 7.78 (m, 2H, H7, H12), 7.71 (t, J J = 6.7 Hz, 1H, H4), 7.62 (s, 1H, H19), 7.50 (d, J J = 5.8 Hz, 1H, H9), 7.33 (s, 1H, H13), 7.07 (t, J J = 6.9 Hz, 1H, H8), 6.57 (s, 1H, H15), 3.76 (s, 1H, H20), 2.48 – 2.36 (m, 1H, H21), 1.94 (s, 1H, H24), 1.80 (d, J J = 10.4 Hz, 1H, H22), 1.59 (s, 2H, H23, H21’), 1.38 – 0.78 (m, 6H, H22’, H23’, H24’, H25, H26, H26’).

[0077] Example 8

[0078]

[0079] At 25 °C, 1 mmol of raw material L2 and 6 mmol of (1R,2R)-1,2-cyclohexanediamine (D2) were added in a molar ratio of 1:6. The reaction was carried out overnight in dichloromethane under argon protection. After the reaction was completed, it was washed with ether and dried to obtain an orange-yellow solid product with a yield of 90%.

[0080] 11H NMR (400 MHz, DMSO-d6): δ 9.44 (s, 1H, H17), 8.87 (d, J J = 7.8 Hz, 1H, H2), 8.27 (t, J J = 7.9 Hz, 1H, H3), 8.13 (d, J J = 8.3 Hz, 1H, H6), 8.01 (d, J J = 5.4 Hz, 1H, H5), 7.91 – 7.78 (m, 2H, H7, H12), 7.71 (t, J J = 6.7 Hz, 1H, H4), 7.62 (s, 1H, H19), 7.50 (d, J J = 5.8 Hz, 1H, H9), 7.33 (s, 1H, H13), 7.07 (t, J J = 6.9 Hz, 1H, H8), 6.57 (s, 1H, H15), 3.76 (s, 1H, H20), 2.48 – 2.36 (m, 1H, H21), 1.94 (s, 1H, H24), 1.80 (d, J J = 10.4 Hz, 1H, H22), 1.59 (s, 2H, H23, H21’), 1.38 – 0.78 (m, 6H, H22’, H23’, H24’, H25, H26, H26’).

[0081] Example 9

[0082]

[0083] At 25 °C, 1 mmol of starting material L1 and 6 mmol of (1R,2R)-1,2-cyclohexanediamine (D2) were added in a molar ratio of 1:6, and the reaction was carried out overnight in dichloromethane under argon protection. After the reaction was completed, it was washed with diethyl ether and dried to obtain an orange-yellow solid product with a yield of 90%.

[0084] 1 1H NMR (400 MHz, DMSO-d6): δ 9.41 (s, 1H, H17), 8.87 (d, J J = 8.8 Hz, 1H, H2), 8.38 – 8.20 (m, 1H, H3), 8.14 (d, J= 8.3 Hz, 1H, H6), 7.98 (s, 1H,H5), 7.93 – 7.79 (m, 2H, H7, H12), 7.71 (s, 1H, H4), 7.61 (s, 1H, H19), 7.50(s, 1H, H9), 7.41 – 7.27 (m, 1H, H13), 7.06 (s, 1H, H8), 6.54 (s, 1H, H15),3.73 (s, 1H, H20), 2.43 (s, 1H, H21), 1.98 (s, 1H, H24), 1.80 (d, J = 11.5Hz, 1H, H22), 1.60 (s, 2H, H23, H21’), 1.45 – 0.50 (m, 6H, H22’, H23’, H24’,H25, H26, H26’).

[0085] Example 10

[0086]

[0087] At 25 °C, 1 mmol of raw material L2 and 6 mmol of (1S,2S)-1,2-cyclohexanediamine (D1) were added in a molar ratio of 1:6. The reaction was carried out overnight in dichloromethane under argon protection. After the reaction was completed, it was washed with ether and dried to obtain an orange-yellow solid product with a yield of 90%.

[0088] 1 H NMR (400 MHz, DMSO-d6): δ 9.41 (s, 1H, H17), 8.87 (d, J = 8.8 Hz,1H, H2), 8.38 – 8.20 (m, 1H, H3), 8.14 (d, J = 8.3 Hz, 1H, H6), 7.98 (s, 1H,H5), 7.93 – 7.79 (m, 2H, H7, H12), 7.71 (s, 1H, H4), 7.61 (s, 1H, H19), 7.50(s, 1H, H9), 7.41 – 7.27 (m, 1H, H13), 7.06 (s, 1H, H8), 6.54 (s, 1H, H15),3.73 (s, 1H, H20), 2.43 (s, 1H, H21), 1.98 (s, 1H, H24), 1.80 (d, J= 11.5 Hz, 1H, H22), 1.60 (s, 2H, H23, H21’), 1.45 – 0.50 (m, 6H, H22’, H23’, H24’, H25, H26, H26’).

[0089] Example 11

[0090] Prepare L1-D1, L2-D2, L1-D2, and L2-D1 into a 10 μM DMSO solution. After degassing with argon bubbling, test their ultraviolet absorption spectra on a TU-1900 double-beam ultraviolet-visible spectrophotometer. As Figure 5 and Figure 6 shown, the ultraviolet-visible absorption spectrum tests of the above helical structures indicate that all four chiral metal complex structure compounds have obvious absorption peaks in the wavelength range of 400 - 430 nm.

[0091] Example 12 Prepare L1-D1, L2-D2, L1-D2, and L2-D1 into a 10 μM DMSO solution. After degassing with argon bubbling, test their fluorescence emission spectra on an FLS-1000 steady-state / transient fluorescence spectrometer. As Figure 7 and Figure 8 shown, the four chiral metal complex structure compounds have the same maximum emission wavelength.

[0092] Example 13 Prepare L1-D1, L2-D2, L1-D2, and L2-D1 into a 10 μM DMSO solution. After degassing with argon bubbling, test their circular dichroism spectra on a J-810 circular dichroism spectrometer. As Figure 9 and Figure 10 shown, the circular dichroism spectrum tests of the chiral complex structures indicate that the four chiral metal complex structure compounds have obvious circular dichroism signals.

[0093] Example 14 The recognition ability differences of compounds L1-D1, L2-D2, L1-D2, and L2-D1 for different anions in DMSO-d6 solution were evaluated through NMR titration experiments. The chiral Ir(III) complex structure was prepared into a 1 mM solution in deuterated dimethyl sulfoxide (DMSO-d6) solvent. The volume of the chiral Ir(III) complex solution was 0.5 mL each time during the test. The DMSO-d6 solutions of Bu4NHSO4, Bu4NCl, Bu4NBr, Bu4NI, (Bu4N)2SO4, Bu4NH2PO4, Bu4NNO3, Bu4NClO4, and Bu4NBF4 were all prepared at concentrations of 0.1 mol / L and 1 mol / L. During the NMR titration, the corresponding anion solution was added dropwise into the NMR tube using a microsyringe, shaken and mixed evenly, and then the NMR was started immediately. 1 1H NMR tests were carried out at room temperature (25 °C). The experimental results are shown in Table 1 as follows: Table 1 Binding constants of metal complexes L1-D1 and L1-D2 for different anions

[0094] Note: L1-D1 and L2-D2 are enantiomers, and L1-D2 and L2-D1 are enantiomers. The binding constants of enantiomers are the same.

[0095] The above chiral metal complexes L1-D1 (enantiomer L2-D2), L1-D2 (enantiomer L2-D1) showed differences in recognition ability for different anions in DMSO-d6 solution. The recognition ability is: SO4 2- >> HSO4 - > H2PO4 - > Cl - > Br - > I - = NO3 - = ClO4 - = BF4 - .

[0096] Example 15 To further and more intuitively understand the hydrogen bonding bonding mode between SO4 2- and the chiral Ir(III) complex, an isothermal titration calorimetry experiment was conducted, and the corresponding n values, enthalpy, and entropy values of the host-guest were obtained. The chiral Ir(III) complex structure was configured into a 5×10 -4 mol / L DMSO solution in a 10 mL volumetric flask; (Bu4N)2SO4 was configured into a 1×10 -2The DMSO solution of mol / L is ready for use. During the test, the injection volume of the host is 950 µL, and the injection volume of the guest is 250 µL. At room temperature, the DMSO solution of 1×10 -2 mol / L (Bu4N)2SO4 was dropped into the DMSO solution of 5×10 -4 mol / L chiral Ir(III) complex. The experimental results show that the binding molar ratio n is close to 0.5, indicating that the stoichiometric ratio of the host to the guest is 2:1. The binding constant was determined to be 1.17×10 5 M -1 . The thermodynamic parameters ΔH is -20.86 kJ / mol and ΔS is 27.06 J / mol·K, indicating that the hydrogen bond interaction between SO4 2- and the chiral Ir(III) complex is an exothermic process.

Claims

1. A series of chiral Ir(III) metal complexes, characterized in that, The complex is selected from the following structures: or ; wherein, Z is S or O, and X - is an anion, and X - is selected from Cl - , Br − , I − , PF6 - , NO3 - , SO4 2- or CF3SO3 - ; Selected from the following structures: ； Among them, m is an integer from 1 to 5; Y - is an anion. When Y - is Cl - 、Br − 、I − 、PF6 - 、NO3 - or CF3SO3 - n is 2; when Y - is SO4 2- n is 1; R is selected from the following structures: 。 2. The preparation method of a series of chiral Ir(III) metal complexes according to claim 1, characterized in that: The complex is selected from the following structures; ； Among them, X - is an anion, and the anion is selected from Cl - , Br − , I − , PF6 - , NO3 - , SO4 2- or CF3SO3 - , and the overall metal complexes L1D1, L2D2, L1D2 or L2D1 are electrically neutral.

3. The series of chiral Ir(III) metal complexes according to claim 2, characterized in that: The complex is selected from the following structures: 。 4. The preparation method of a series of chiral Ir(III) metal complexes according to claim 1, characterized in that: The complex is obtained by reacting the chiral Ir(III) complex building block M1 or M2 with diamine respectively; The structures of the chiral Ir(III) complex building blocks M1 and M2 are as follows: ； wherein, R’ is -NCS or -NCO; X - , Y - , n, m, are defined in the same manner as those in the metal complex of claim 1; The diamine is: 。 5. The preparation method of a series of chiral Ir(III) metal complexes according to claim 2, characterized in that: The metal complex is obtained by reacting the chiral Ir(III) complex building block L1 or L2 with the chiral diamine D1 or D2 respectively; The structures of the chiral Ir(III) complex building blocks L1 and L2 are: ； wherein X - is defined in the same manner as the compound in claim 1; The chiral diamine D1 is (1S,2 S )-1,2-cyclohexanediamine; The chiral diamine D2 is (1 R ,2 R )-1,2-cyclohexanediamine.

6. The preparation method according to claim 5, characterized in that, It includes the following steps: 1) Add the chiral Ir(III) complex building block L1 or L2 and the chiral diamine D1 or D2 into dichloromethane solution according to a molar ratio of 1:6, and react overnight at room temperature; 2) Distill the reaction solution under reduced pressure to obtain a crude product, and obtain the target compound by recrystallization with ether.

7. Use of a series of chiral Ir(III) metal complexes according to any one of claims 1-3, characterized in that: The metal complex is used for selectively recognizing anions in solution.

8. Use of the series of chiral Ir(III) metal complexes according to claim 5, characterized in that: The metal complex is applied to selectively recognize SO4 2- anions in solution.

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