Preparation method and application of a carboxyl-containing half-sandwich type iridium complex

Abstract

The present invention discloses a method for preparing and applying a carboxyl-containing half-sandwich iridium complex. The complex structure is shown in Formula (I). A ligand and a dimer react under reaction conditions. A base or alkaline solvent B is then added to the reaction system. The base or alkaline solvent B selectively removes protons from the phenolic hydroxyl groups of the ligand without interacting with the carboxyl groups on the ligand, thereby producing the half-sandwich iridium complex (I). This complex exhibits excellent anticancer activity, with performance comparable to or even superior to commercial cisplatin, making it a promising anticancer drug. #imgabs0#

Description

Technical Field

[0001] The invention relates to a metal complex, in particular to a preparation method and application of a carboxyl-containing half-sandwich type iridium complex, belonging to the field of chemical pharmacy. Background Art

[0002] The rapid increase in cancer cases worldwide has necessitated the development and screening of potential anticancer drugs. For decades, cisplatin and its derivatives have been successfully used in the treatment of malignant tumors with remarkable success. However, these widely used platinum-based anticancer drugs are associated with numerous drawbacks, including high toxicity, adverse side effects, and drug resistance. The advantages and limitations of cisplatin-based chemotherapeutics have prompted further research into alternative metal anticancer complexes. Several new organometallic complexes are considered the most promising anticancer agents due to their diverse structures, potential redox properties, and wide range of ligand substitution ratios. For example, iridium(III), iron(II), ruthenium(II), and rhodium(II) have been used in antitumor research with promising results. Among them, half-sandwich-type iridium complexes have attracted widespread attention due to their easily tunable structures, excellent anticancer activity, and specific mechanisms of action (MoAs). Currently, the large number of such complexes synthesized are generally divided into cationic and neutral complexes. Peter J. Saler synthesized a cationic (metal center is in cationic form) half-sandwich iridium complex with an N^N bidentate chelating ligand and a neutral (metal center is electrically neutral) half-sandwich iridium complex with a C^N bidentate chelating ligand (see formulas a and b below, Acc. Chem. Res. 2014, 47, 1174-1185). In the cationic half-sandwich iridium complex (see formula a below), the ligand adopts a bidentate neutral chelation mode, the metal center is in cationic form, and is balanced by an external anion. In contrast, in the neutral half-sandwich iridium complex (see formula b below), the bidentate chelating ligand is negatively charged (usually monovalent), and the entire complex remains neutral, with no counterions present.

[0003] Carboxyl groups are widely present in many drug molecules and can specifically interact with target molecules, thereby exerting therapeutic effects. Carboxyl groups are hydrophilic groups that enhance drug solubility and facilitate drug administration. They can also improve drug stability and controlled release, as well as absorption and delivery. Rational design and modification of carboxyl groups can enhance drug targeting and selectivity while reducing side effects. Therefore, the introduction of carboxyl groups can significantly enhance the anticancer activity of metal complexes and promote apoptosis in cancer cells. It is important to note that because the carboxyl groups on carboxylic acid ligands can bond and coordinate with the metal in the same plane, partially or completely deprotonating during the coordination process, the introduction of carboxyl groups into the ligand may result in competition with the chelating sites on the ligand for coordination with the metal, leading to a chaotic reaction or even failure to obtain the target complex.

[0004] Summary of the Invention

[0005] In the system of the present invention, the phenolic hydroxyl groups on the ligand are selectively deprotonated by alkali or alkaline solvent without interacting with the protons on the carboxyl groups, thereby successfully synthesizing carboxyl-containing half-sandwich-type N^O chelate complexes. The anticancer activity of the carboxyl-containing complexes is superior to that of the complexes without carboxyl groups.

[0006] A series of carboxyl-containing ligands with different substituents are introduced to obtain a series of novel half-sandwich iridium complexes with good anti-tumor effects. These novel half-sandwich iridium complexes show excellent anti-tumor effects.

[0007] The molecular structure of the carboxyl-containing half-sandwich iridium complex is:

[0008]

[0009] In the formula, R1, R2, and R3 can be hydrogen, C1-C 15 Alkyl, halogen or halogenated C1~C 15 An alkyl group; R4 is R5 is one of Cl, CH3O, CH3COO, and triphenylphosphine.

[0010] The carboxyl-containing half-sandwich type iridium complex of the present invention, wherein in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 1; in Formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 2; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is tert-butyl, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 3; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is tert-butyl, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 4; in the formula (I), R1 is hydrogen, R2 is tert-butyl, R3 is tert-butyl, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 5; in the formula (I), R1 is fluorine, R2 is tert-butyl, R3 is tert-butyl, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 6; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 7; in Formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 8; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 9; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 10; in Formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 11; in Formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is R5 is Cl, and the specific structural formula is shown in Formula 12;

[0011]

[0012] The preparation method of the carboxyl-containing half-sandwich iridium complex of the present invention comprises the following steps: under nitrogen protection, reacting a dimer represented by formula (III), a carboxyl-containing ligand represented by formula (II), and a base or alkaline solvent B in methanol as a solvent at room temperature for 8 hours to obtain a carboxyl-containing half-sandwich iridium complex represented by formula (I); the complex is an 18-electron complex, and when sodium methoxide or sodium acetate is added as B, the purpose is to remove a proton H on the phenolic hydroxyl group of the ligand, thereby converting the ligand into an anionic ligand and coordinating with the metal center as an N^O chelate ligand; this process requires the base or alkaline solvent B to selectively remove the proton on the phenolic hydroxyl group of the ligand without reacting with the carboxyl group. The specific synthesis route is as follows:

[0013]

[0014] When the complex is 1, it is prepared by the following method:

[0015] Under nitrogen protection, 30.05 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 18.66 mg of the ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate, and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 1.

[0016] When the complex is 2, it is prepared by the following method:

[0017] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 19.95 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 2.

[0018] When the complex is 3, it is prepared by the following method:

[0019] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 22.89 mg of the ligand (formula (II) R1 = R2 = hydrogen, R3 = tert-butyl), 20 mg of sodium acetate, and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved in dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 3.

[0020] When the complex is 4, it is prepared by the following method:

[0021] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 23.96 mg of ligand (formula (II) R1 = fluorine, R2 = hydrogen, R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved in dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 4.

[0022] When the complex is 5, it is prepared by the following method:

[0023] Under nitrogen protection, 30.05 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 26.78 mg of the ligand (formula (II) R1 = hydrogen, R2 = R3 = tert-butyl), 20 mg of sodium acetate, and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 5.

[0024] When the complex is 6, it is prepared by the following method:

[0025] Under nitrogen protection, 29.99 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 28.12 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 6.

[0026] When the complex is 7, it is prepared by the following method:

[0027] Under nitrogen protection, 54.98 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.88 mg of ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 7.

[0028] When the complex is 8, it is prepared by the following method:

[0029] Under nitrogen protection, 50.06 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.55 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 8.

[0030] When the complex is 9, it is prepared by the following method:

[0031] Under nitrogen protection, 46.00 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.34 mg of ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 9.

[0032] When the complex is 10, it is prepared by the following method:

[0033] Under nitrogen protection, 45.97 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 26.12 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate, and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved in dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 10.

[0034] When the complex is 11, it is prepared by the following method:

[0035] Under nitrogen protection, 30.24 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 15.62 mg of the ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate, and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved in dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core, washed with n-hexane, and dried in vacuo to obtain a red solid 11.

[0036] The complex is 12, and is prepared by the following method:

[0037] Under nitrogen protection, 35.03 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 19.86 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 12.

[0038] Beneficial effects

[0039] (1) The present invention provides a method for preparing a carboxyl-containing half-sandwich-type iridium complex, thereby obtaining a series of novel half-sandwich-type complexes with good anti-tumor effects.

[0040] (2) The synthesis of the complex is as follows: the ligand and the dimer react with a base or a basic solvent B under reaction conditions to obtain a novel half-sandwich type iridium complex I.

[0041] (3) This type of carboxyl-containing half-sandwich iridium complex exhibits excellent anti-tumor effects. The anti-cancer activity of the carboxyl-containing complex is better than that of the non-carboxyl-containing complex, and it is a very promising anti-cancer drug. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is the H NMR spectrum of complex 1 of the present invention.

[0043] Figure 2 is the mass spectrum of complex 1 of the present invention.

[0044] Figure 3 is the H NMR spectrum of complex 2 of the present invention.

[0045] Figure 4 is the mass spectrum of complex 2 of the present invention.

[0046] Figure 5 The H NMR spectrum of complex 3 of the present invention is

[0047] Figure 6 is the mass spectrum of complex 3 of the present invention.

[0048] Figure 7 is the H NMR spectrum of complex 4 of the present invention.

[0049] Figure 8 is the mass spectrum of complex 4 of the present invention.

[0050] Figure 9 is the H NMR spectrum of complex 5 of the present invention.

[0051] Figure 10 is the mass spectrum of complex 5 of the present invention.

[0052] Figure 11 is the H NMR spectrum of complex 6 of the present invention.

[0053] Figure 12 is the mass spectrum of complex 6 of the present invention.

[0054] Figure 13 is the H NMR spectrum of complex 7 of the present invention.

[0055] Figure 14 is the mass spectrum of complex 7 of the present invention.

[0056] Figure 15 is the H NMR spectrum of complex 8 of the present invention.

[0057] Figure 16 is the mass spectrum of complex 8 of the present invention.

[0058] Figure 17 is the H NMR spectrum of complex 9 of the present invention.

[0059] Figure 18 is the mass spectrum of complex 9 of the present invention.

[0060] Figure 19 is the H NMR spectrum of complex 10 of the present invention.

[0061] Figure 20 is the mass spectrum of complex 10 of the present invention.

[0062] Figure 21 is the H NMR spectrum of complex 11 of the present invention.

[0063] Figure 22 is the mass spectrum of complex 11 of the present invention.

[0064] Figure 23 This is the single crystal structure of complex 11 of the present invention.

[0065] Figure 24 is the H NMR spectrum of complex 12 of the present invention.

[0066] Figure 25 This is the mass spectrum of complex 12 of the present invention.

[0067] Figure 26 This is the H NMR spectrum of the comparative example complex 13 of the present invention.

[0068] Figure 27 13 is the mass spectrum of the comparative example complex 13 of the present invention.

[0069] Figure 28 This is the H NMR spectrum of the comparative example complex 14 of the present invention.

[0070] Figure 29 14 is the mass spectrum of the comparative example complex 14 of the present invention. DETAILED DESCRIPTION

[0071] The present invention is further illustrated by the following examples of some representative compounds, but these illustrations are not intended to limit the present invention.

[0072] The starting compounds used in the synthesis of the compounds are either commercial products or can be prepared from known synthetic methods. The preparation methods of all organic compounds are available from the literature, and these methods are basic and obvious to synthetic chemists. Therefore, the description of the following synthetic methods can be considered to be detailed and specific.

[0073] Example 1

[0074] When the complex is 1, it is prepared by the following method:

[0075] Under nitrogen protection, 30.05 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 18.66 mg of ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 1.

[0076] NMR characterization 1H NMR (500MHz, CD3OD) δ8.29(s,1H,CH=N),8.10–8.05(m,2H),7.88–7.81(m,2H),7.39(m,J=8.7,6.9,1. 9Hz,1H),7.32(m,J=7.9,1.9Hz,1H),6.89(d,J=8.5Hz,1H),6.57–6.52(m,1H),1.30(s,15H,Cp*-CH3).

[0077] Mass Spectrum: C 24 H 25 The theoretical value of IrNO3 is 568.14637, the actual value is 568.1474, [M-Cl] + .

[0078] Elemental analysis: theoretical value C 24 H 25 ClIrNO3: C, 47.79; H, 4.18; N, 2.32, Actual measured: C, 47.97; H, 4.16; N, 2.31.

[0079] Example 2

[0080] When the complex is 2, it is prepared by the following method:

[0081] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 19.95 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 2.

[0082] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.37(s,1H,CH=N),7.94(t,J=8.1Hz,1H),7.78(d,J=11.9Hz,1H),7.56(m,J=8.4,2.2Hz,1H), 7.44–7.40(m,1H),7.35(m,J=8.1,1.9Hz,1H),6.93(d,J=8.5Hz,1H),6.58(t,J=7.4Hz,1H),1.34(s,15H,Cp*-CH3).

[0083] Mass Spectrum: C 24 H24 Theoretical value of FIrNO3 is 586.13695, and the actual value is 586.1371, [M-Cl] + .

[0084] Elemental analysis: theoretical value C 24 H 24 FClIrNO3: C, 46.41; H, 3.89; N, 2.26, measured: C, 46.59; H, 3.87; N, 2.25.

[0085] Example 3

[0086] When the complex is 3, it is prepared by the following method:

[0087] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 22.89 mg of ligand (formula (II) R1 = R2 = hydrogen, R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 3.

[0088] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.16–8.03(m,3H),7.56(d,J=8.1Hz,2H),7.40–7.34(m,1H),7.04(d,J=7.3 Hz,1H),6.42(t,J=7.8Hz,1H),1.46(t,J=3.1Hz,9H,C(CH3)3),1.38(d,J=2.4Hz,15H,Cp*-CH3).

[0089] Mass Spectrum: C 28 H 33 Theoretical value of IrNO3 is 624.20897, and the actual value is 624.20678, [M-Cl] + .

[0090] Elemental analysis: theoretical value C 28 H 33 ClIrNO3: C, 51.01; H, 5.05; N, 2.12, measured: C, 51.22; H, 5.03; N, 2.11.

[0091] Example 4

[0092] When the complex is 4, it is prepared by the following method:

[0093] Under nitrogen protection, 30.02 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 23.96 mg of ligand (formula (II) R1 = fluorine, R2 = hydrogen, R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 4.

[0094] NMR characterization 1 H NMR(500MHz,CD3OD)δ8.31(s,1H,CH=N),7.91(t,J=8.0Hz,1H),7.49–7.44(m,2H),7.33(m,J=8.3,2.1Hz,1H), 7.14(m,J=7.9,1.8Hz,1H),6.54(t,J=7.5Hz,1H),1.49(s,9H,C(CH3)3),1.44(d,J=1.1Hz,15H,Cp*-CH3). Mass spectrum: C 28 H 32 Theoretical value of FIrNO3 is 642.19955, and the actual value is 642.2005, [M-Cl] + .

[0095] Elemental analysis: theoretical value C 28 H 32 FClIrNO3: C, 49.66; H, 4.76; N, 2.07, measured: C, 49.82; H, 4.74; N, 2.06.

[0096] Example 5

[0097] When the complex is 5, it is prepared by the following method:

[0098] Under nitrogen protection, 30.05 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 26.78 mg of ligand (formula (II) R1 = hydrogen, R2 = R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 5.

[0099] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.17(s,1H,CH=N),8.11(d,J=8.4Hz,2H),7.59(d,J=8.4Hz,2H),7.54(d,J=2.6 Hz,1H),7.03(d,J=2.6Hz,1H),1.49(s,9H,C(CH3)3),1.39(s,15H,Cp*-CH3),1.25(s,9H,C(CH3)3).

[0100] Mass Spectrum: C 32 H 41 The theoretical value of IrNO3 is 680.27157, the actual value is 680.26913, [M-Cl] + .

[0101] Elemental analysis: theoretical value C 32 H 41 ClIrNO3: C, 53.73; H, 5.78; N, 1.96, Actual Measured: C, 53.95; H, 5.76; N, 1.95.

[0102] Example 6

[0103] When the complex is 6, it is prepared by the following method:

[0104] Under nitrogen protection, 29.99 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 28.12 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = tert-butyl), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 6.

[0105] NMR characterization 1H NMR (500MHz, CD3OD) δ8.51(s,1H,CH=N),7.86(t,J=8.0Hz,1H),7.68(d,J=2.5Hz,1H),7.41(d,J=10.2Hz,1H),7.28 (m,J=8.2,2.1Hz,1H),7.21(d,J=2.6Hz,1H),1.54(s,9H,C(CH3)3),1.48(s,15H,Cp*-CH3),1.27(s,9H,C(CH3)3).

[0106] Mass Spectrum: C 32 H 40 Theoretical value of FIrNO3 is 698.26215, and the actual value is 698.2632, [M-Cl] + .

[0107] Elemental analysis: theoretical value C 32 H 40 FClIrNO3: C, 52.41; H, 5.50; N, 1.91, measured: C, 52.62; H, 5.48; N, 1.90.

[0108] Example 7

[0109] When the complex is 7, it is prepared by the following method:

[0110] Under nitrogen protection, 54.98 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.88 mg of ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 7.

[0111] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.32(s,1H,CH=N),7.99(d,J=8.4Hz,2H),7.73(d,J=8.5Hz,2H),7.62–7.59(m,2H ),7.52(d,J=8.2Hz,2H),7.43–7.35(m,7H),6.92(d,J=8.5Hz,1H),6.59(t,J=7.4Hz,1H),1.54(s,6H,Cp biph -CH3),1.16(s,6H,Cp biph-CH3).

[0112] Mass Spectrum: C 35 H 31 The theoretical value of IrNO3 is 706.19332, the actual value is 706.1935, [M-Cl] + .

[0113] Elemental analysis: theoretical value C 35 H 31 ClIrNO3: C, 56.71; H, 4.22; N, 1.89, measured: C, 56.90; H, 4.20; N, 1.88.

[0114] Example 8

[0115] When the complex is 8, it is prepared by the following method:

[0116] Under nitrogen protection, 50.06 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.55 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 8.

[0117] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.31(s,1H,CH=N),7.81(s,1H),7.60(d,J=7.2Hz,2H),7.52(d,J=8 .3Hz,2H),7.44–7.33(m,9H),6.91(d,J=8.6Hz,1H),6.58(t,J=7.4Hz,1H),1.56(s,6H,Cp biph -CH3),1.21(s,6H,Cp biph -CH3). Mass Spectrum: C 35 H 30 Theoretical value of FIrNO3 is 724.18390, and the actual value is 724.1841, [M-Cl] + .

[0118] Elemental analysis: theoretical value C 35 H 30 ClFIrNO3: C, 55.37; H, 3.98; N, 1.84, measured: C, 55.50; H, 3.96; N, 1.83.

[0119] Example 9

[0120] When the complex is 9, it is prepared by the following method:

[0121] Under nitrogen protection, 46.00 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 24.34 mg of ligand (formula (II) R1=R2=R3=hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 9.

[0122] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.30(s,1H,CH=N),7.97(d,J=8.6Hz,2H),7.68(d,J=8.5Hz,2H),7. 42(s,1H),7.32–7.26(m,6H),6.90(d,J=8.5Hz,1H),6.58(t,J=6.9Hz,1H),1.54(s,6H,Cp biph -CH3),1.09(s,6H,Cp biph -CH3). Mass Spectrum: C 29 H 27 The theoretical value of IrNO3 is 630.16202, the actual value is 630.1633, [M-Cl] + .

[0123] Elemental analysis: theoretical value C 29 H 27 ClIrNO3: C, 52.36; H, 4.09; N, 2.11, measured: C, 52.55; H, 4.07; N, 2.10.

[0124] Example 10

[0125] When the complex is 10, it is prepared by the following method:

[0126] Under nitrogen protection, 45.97 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 26.12 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 10.

[0127] NMR characterization 1 H NMR (500MHz, CD3OD) δ8.30(s,1H,CH=N),7.82(t,J=8.1Hz,1H),7.64(d,J=14.0Hz,1H),7.44 –7.36(m,3H),7.33–7.26(m,5H),6.88(d,J=8.5Hz,1H),6.58(t,J=7.4Hz,1H),1.55(s,6H,Cp biph -CH3),1.15(s,6H,Cp biph -CH3).

[0128] Mass Spectrum: C 29 H 26 Theoretical value of FIrNO3 is 648.15260, and the actual value is 648.1534, [M-Cl] + .

[0129] Elemental analysis: theoretical value C 29 H 26 ClFIrNO3: C, 55.31; H, 4.32; N, 2.22, Actual measured: C, 55.52; H, 4.30; N, 2.21.

[0130] Example 11

[0131] When the complex is 11, it is prepared by the following method:

[0132] Under nitrogen protection, 30.24 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 15.62 mg of ligand (formula (II) R1 = R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 hours. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a minimum using a rotary evaporator. An excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane. It was then dried under vacuum to obtain a red solid 11. Single crystals of the complex 11 were obtained by slowly diffusing n-hexane into a dichloromethane solution at room temperature. NMR characterization was as follows: 1H NMR (500MHz, CD3OD) δ8.37(s,1H,CH=N),8.00(d,J=8.3Hz,2H),7.69(d,J=8.2Hz,2H),7.40(d,J=7.8Hz,2H),7.23–7. 19(m,3H),6.96(d,J=7.4Hz,1H),6.87(d,J=8.5Hz,1H),6.59(t,J=7.4Hz,1H),2.05(s,3H,arene-CH3),1.60(s,6H,Cp biph -CH3),0.90(s,6H,Cp biph -CH3).

[0133] Mass Spectrum: C 30 H 29 Theoretical value of IrNO3 is 644.17767, and the actual value is 644.1776, [M-Cl] + .

[0134] Elemental analysis: theoretical value C 30 H 29 ClIrNO3: C, 53.05; H, 4.30; N, 2.06, measured: C, 53.27; H, 4.28; N, 2.05.

[0135] Example 12

[0136] The complex is 12, and is prepared by the following method:

[0137] Under nitrogen protection, 35.03 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 19.86 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 12.

[0138] NMR characterization 1H NMR (500MHz, CD3OD) δ8.37(s,1H,CH=N),7.82(t,J=7.9Hz,1H),7.67(d,J=11.5Hz,1H),7.41(t,J=7.8Hz,3H),7.24–7. 18(m,3H),6.95(t,J=7.3Hz,1H),6.85(d,J=8.5Hz,1H),6.59(t,J=7.4Hz,1H),2.06(s,3H,arene-CH3),1.61(s,6H,Cp biph -CH3),0.93(s,6H,Cp biph -CH3).

[0139] Mass Spectrum: C 30 H 28 Theoretical value of FIrNO3 is 662.16825, and the actual value is 662.1768, [M-Cl] + .

[0140] Elemental analysis: theoretical value C 30 H 28 ClFIrNO3: C, 51.68; H, 4.05; N, 2.01, measured: C, 51.85; H, 4.03; N, 2.00.

[0141] Comparative Example 1

[0142] When the complex is 13, it is prepared by the following method:

[0143] Under nitrogen protection, 49.98 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 20.06 mg of ligand (formula (II) R1=R2=R3=hydrogen, no COOH), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent n-hexane was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 13.

[0144] NMR characterization 1H NMR (500MHz, CD3OD) δ8.11(s,1H,CH=N),7.48(d,J=8.7Hz,2H),7.42(d,J=6.7Hz,2H),7.40–7.37(m,2H),7.31(t,J=7.6Hz,2H),7.27(s,2H) ,7.26(s,1H),7.22(d,J=10.0Hz,2H),7.04(d,J=8.3Hz,2H),6.79(d,J=8.5Hz,1H),6.48–6.44(m,1H),2.24(s,3H,Aryl-CH3),1.43(s,6H,Cp biph -CH3),1.01(s,6H,Cp biph -CH3).

[0145] Mass Spectrum: C 35 H 33 The theoretical value of IrNO is 676.2191, the actual value is 676.2220, [M-Cl] + .

[0146] Elemental analysis: theoretical value C 35 H 33 ClIrNO: C, 59.10; H, 4.68; N, 1.97, found: C, 59.29; H, 4.66; N, 1.96.

[0147] Comparative Example 2

[0148] The complex is 14, and is prepared by the following method:

[0149] Under nitrogen protection, 50.05 mg of iridium dimer (Formula (III)) was added to a 100 mL Schlenk bottle. 21.98 mg of ligand (formula (II) R1 = fluorine, R2 = R3 = hydrogen, no COOH), 20 mg of sodium acetate and 10 mL of anhydrous methanol were reacted at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved in dichloromethane and filtered through a sand core to remove the sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried in vacuo to obtain a red solid 14.

[0150] The NMR characterization is: 1H NMR (500MHz, CD3OD) δ8.14(s,1H,CH=N),7.50–7.43(m,3H),7.39(d,J=8.2Hz,2H),7.32(t,J=7.7Hz,3H),7.27(d,J=8.2Hz,2H),7.23(d,J =4.1Hz,2H),7.16(d,J=8.2Hz,1H),7.08(t,J=8.2Hz,1H),6.79(d,J=8.6Hz,1H),6.49–6.45(m,1H),2.16(s,3H,Aryl-CH3),1.43(s,6H,Cp biph -CH3),1.07(s,6H,Cp biph -CH3).

[0151] Mass Spectrum: C 35 H 32 Theoretical value of FIrNO is 694.2097, and the actual value is 694.2098, [M-Cl] + .

[0152] Elemental analysis: theoretical value C 35 H 32 ClFIrNO: C, 60.59; H, 4.65; N, 2.02, Actual Measured: C, 60.78; H, 4.63; N, 2.01

[0153] Example 13

[0154] Experimental study on the proliferation inhibition of tumor cell lines by complexes 1-12 with anticancer activity:

[0155] (1) Preparation of test compounds: Dissolve the solid complex in DMSO to prepare a stock solution of a certain concentration. Further dilute the stock solution with cell culture medium until the working concentration is reached, and incubate for 24 h.

[0156] (2) Cell growth inhibition assay (MTT method):

[0157] 1) 5000 human cervical cancer cells (HeLa) and human non-small cell lung cancer cells (A549) were prepared into cell suspensions and inoculated into 96-well culture plates;

[0158] 2) Pre-culture cells with drug-free medium, incubate at 5% CO2, 310K for 24 hours, add the prepared test compound, and incubate for 24 hours;

[0159] 3) Add 15 μL of 5 mg / mL MTT solution to each well and continue incubation for 4 hours to form purple crystalline formazan.

[0160] 4) Terminate the culture, carefully aspirate the culture medium from the wells, add 100 μL of DMSO to each well to fully dissolve the formazan precipitate, mix on an oscillator, and measure the optical density of each well at a wavelength of 570 nm using a microplate reader.

[0161] 5) Each experiment was repeated three times, IC 50 = Mean ± SEM. The inhibition rates of complexes 1-12 and commercial cisplatin on the growth of HeLa and A549 cancer cells are shown in Table 1.

[0162] Table 1

[0163]

[0164] As shown in Table 1, all complexes exhibited good anticancer activity, with some complexes approaching the activity of commercially available cisplatin. Furthermore, a comparison of complex 7 (containing a carboxyl group) with complex 13 (not containing a carboxyl group), and complex 8 (containing a carboxyl group) with complex 14 (not containing a carboxyl group), revealed that the carboxyl-containing complexes exhibited superior anticancer activity compared to the non-carboxyl-containing complexes. A comparison of complexes 1-12 revealed that changes in the ligand substituents R1-R3 had little effect on the anticancer activity of the complexes. A comparison of complexes 1, 7, and 9, or complexes 2, 8, and 10, revealed that the introduction of an aryl group at the R4 position of the cyclopentadienyl ring enhanced the anticancer activity, with the complexes containing biphenyl substituted on the cyclopentadienyl ring exhibiting the highest activity. These findings provide a theoretical basis for the preparation of novel antitumor drugs.

[0165] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A carboxyl-containing half-sandwich type iridium complex, characterized in that: The structural formula is shown in formula (I): ； In the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 1; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 2; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is tert-butyl, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 3; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is tert-butyl, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 4; in the formula (I), R1 is hydrogen, R2 is tert-butyl, R3 is tert-butyl, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 5; in the formula (I), R1 is fluorine, R2 is tert-butyl, R3 is tert-butyl, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 6; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 7; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 8; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 9; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 10; in the formula (I), R1 is hydrogen, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 11; in the formula (I), R1 is fluorine, R2 is hydrogen, R3 is hydrogen, and R4 is , R5 is Cl, and the specific structural formula is shown in Formula 12; 。 2. A method for preparing the carboxyl-containing half-sandwich type iridium complex according to claim 1, characterized in that: The following steps are involved: Under nitrogen protection, a dimer represented by formula (III), a carboxyl-containing ligand represented by formula (II), and a base or alkaline solvent B are reacted in methanol at room temperature for 24 hours to obtain a carboxyl-containing half-sandwich iridium complex represented by formula (I). This complex is an 18-electron complex. When sodium methoxide or sodium acetate is added as B, the purpose is to remove a proton H on the phenolic hydroxyl group of the ligand, turning the ligand into an anionic ligand and coordinating with the metal center as an N^O chelate ligand. The synthetic route is: 。 3. The preparation method according to claim 2, characterized in that When the complex is 1, it is prepared by the following method: Under nitrogen protection, 30.05 mg of iridium dimer of formula (III), 18.66 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = , where R1=R2=R3=hydrogen in formula (II), react at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 1. When the complex is 2, it is prepared by the following method: Under nitrogen protection, 30.02 mg of iridium dimer of formula (III), 19.95 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = R3 = hydrogen, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 2. When the complex is 3, it is prepared by the following method: Under nitrogen protection, 30.02 mg of iridium dimer of formula (III), 22.89 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1=R2=hydrogen, R3=tert-butyl, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 3. When the complex is 4, it is prepared by the following method: Under nitrogen protection, 30.02 mg of iridium dimer of formula (III), 23.96 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = hydrogen, and R3 = tert-butyl. The reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane. The sodium acetate was removed by filtration through a sand core. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and then dried under vacuum to obtain a red solid 4. When the complex is 5, it is prepared by the following method: Under nitrogen protection, 30.05 mg of iridium dimer of formula (III), 26.78 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = hydrogen, R2 = R3 = tert-butyl, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 5. When the complex is 6, it is prepared by the following method: Under nitrogen protection, 29.99 mg of iridium dimer of formula (III), 28.12 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = R3 = tert-butyl, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and then dried under vacuum to obtain a red solid 6. When the complex is 7, it is prepared by the following method: Under nitrogen protection, 54.98 mg of iridium dimer of formula (III), 24.88 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = , where R1=R2=R3=hydrogen in formula (II), react at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and excess n-hexane, a poor solvent, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 7. When the complex is 8, it is prepared by the following method: Under nitrogen protection, 50.06 mg of iridium dimer of formula (III), 24.55 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = R3 = hydrogen, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 8. When the complex is 9, it is prepared by the following method: Under nitrogen protection, 46.00 mg of iridium dimer of formula (III), 24.34 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = , where R1=R2=R3=hydrogen in formula (II), react at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and excess n-hexane, a poor solvent, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 9. When the complex is 10, it is prepared by the following method: Under nitrogen protection, 45.97 mg of iridium dimer of formula (III), 26.12 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = R3 = hydrogen, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 10. When the complex is 11, it is prepared by the following method: Under nitrogen protection, 30.24 mg of iridium dimer of formula (III), 15.62 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = , where R1=R2=R3=hydrogen in formula (II), react at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a minimum using a rotary evaporator, and excess n-hexane, a poor solvent, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 11. The complex is 12, and is prepared by the following method: Under nitrogen protection, 35.03 mg of iridium dimer of formula (III), 19.86 mg of ligand of formula (II), 20 mg of sodium acetate and 10 mL of anhydrous methanol were added to a 100 mL Schlenk flask, wherein R4 in formula (III) = In formula (II), R1 = fluorine, R2 = R3 = hydrogen, and the reaction was carried out at room temperature for 12 h. After the reaction, the solvent was dried on a rotary evaporator, and the remaining solid was dissolved with dichloromethane and filtered through a sand core to remove sodium acetate. The filtrate was spun down to a small amount using a rotary evaporator, and an excess of a poor solvent, n-hexane, was added to produce a precipitate. The precipitate was filtered through a sand core and washed with n-hexane, and dried under vacuum to obtain a red solid 12.

4. Use of the carboxyl-containing half-sandwich type iridium complex according to claim 1 in the preparation of anticancer drugs, characterized in that: The cancer is liver cancer, lung cancer or cervical cancer.

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