A terpyridine zinc complex, a preparation method and application thereof

Abstract

The application discloses a terpyridine zinc complex and a preparation method and application thereof, and belongs to the technical field of materials. The terpyridine zinc complex has the following molecular structure: wherein X is a counter anion; R1 and R2 are independently selected from a nitrogen heterocyclic unit, a benzene ring unit or a triphenylamine unit. The terpyridine zinc complex has a semiconductor property, can generate hydrogen peroxide under sunlight together with water and oxygen, and can be applied as a photosensitizer or a photocatalyst.

Description

Technical Field

[0001] The present invention relates to a zinc complex, in particular to a terpyridine zinc complex, and also to a preparation method of the terpyridine zinc complex and application of the terpyridine zinc complex as a photocatalyst or photosensitizer, belonging to the field of material technology. Background Art

[0002] Over the past few decades, due to people's growing awareness of the ongoing energy crisis and increasingly serious environmental pollution, photocatalytic technology that directly converts solar energy into fuels has attracted extensive research. So far, inorganic semiconductor materials and organic polymer materials, such as MOF, COF and polymeric carbon nitride (C3N4), have been widely used as photocatalysts in the past decade due to their visible light response, environmental friendliness and structural tunability. In contrast, molecular photocatalysts have outstanding intrinsic activity due to their designable structure and tunable photophysical properties at the atomic level. In organic molecular photocatalysis, due to the high exciton binding energy and short excited state lifetime of organic molecules, it is necessary to construct a strong built-in electric field through molecular assembly to achieve the formation and subsequent migration of long-lived photogenerated carriers. In addition, noble metal compounds with long-lived triplet states, such as ruthenium, iridium, platinum, and rhenium complexes, have been widely used as photosensitizers in homogeneous photosynthesis due to their long excited state lifetimes, which allow sufficient time for reactions. However, the migration process of photogenerated electrons and holes between photosensitive units to the catalyst sites is very complex, and the understanding and effective management of this process are fraught with obstacles, which seriously hinders the development of photocatalytic technology.

[0003] The molecular photocatalytic systems currently under study usually consist of two parts: a photosensitizer responsible for absorbing visible light to produce excitons and a catalyst responsible for carrying out chemical reactions. Single-molecule catalysts, while acting as both photosensitizers and photocatalysts, have the fundamental advantage of achieving superior performance due to their atomic economy and structural precision. Summary of the Invention

[0004] In order to solve the technical problems existing in the prior art, the first object of the present invention is to provide a terpyridine zinc complex having semiconductor properties and capable of generating hydrogen peroxide with water and oxygen under sunlight.

[0005] The second object of the present invention is to provide a method for synthesizing a terpyridine zinc complex, which has mild reaction conditions, simple operation, and is easy to scale up production.

[0006] A third object of the present invention is to provide a terpyridine zinc complex for use as a photosensitizer or photocatalyst. The terpyridine zinc complex can rapidly achieve electron-hole separation under the excitation of a xenon lamp and can induce a variety of free radicals within the valence band and conduction band. Furthermore, under irradiation with sunlight, the terpyridine zinc complex can efficiently combine with oxygen to produce hydrogen peroxide in an aqueous solution. Thus, the complex has broad application prospects in various fields, such as as a photosensitizer and photocatalyst.

[0007] In order to achieve the above technical objectives, the present invention provides a terpyridine zinc complex having a molecular structure shown in Formula 1:

[0008]

[0009] in,

[0010] X is the counter anion;

[0011] R1 and R2 are independently selected from a nitrogen heterocyclic unit, a benzene ring unit or a triphenylamine unit.

[0012] The terpyridine zinc complex of the present invention uses transition metal zinc as a central metal ion and terpyridines as multidentate ligands. The terpyridine ligands can form a stable terpyridine zinc complex with a pseudo-octahedral structure with zinc ions. In addition, a triphenylamine group and a nitrogen heterocyclic group with high electron-donating ability are introduced into the terpyridine zinc complex. The terpyridine ligand itself has a strong electron-withdrawing ability. The strong electron-donating ability of the triphenylamine group and the nitrogen heterocyclic group further enhances the electron push-pull effect and the special charge transfer effect, so that the terpyridine zinc complex has an extremely small energy gap difference (ΔE ST ), and under sunlight conditions, the terpyridine zinc complex can combine water and oxygen to generate hydrogen peroxide with high efficiency, and can be used as a very excellent photocatalyst or photosensitizer.

[0013] As a preferred embodiment, in the terpyridine zinc complex, X is PF6 - The terpyridine zinc complex of the present invention is selected from PF6 - As a counter anion, compared to NO3 -Other anions such as terpyridine zinc can better improve the hydrophilicity of the terpyridine zinc complex.

[0014] As a preferred solution, R1 is

[0015] As a preferred solution, R2 is

[0016]

[0017] In the terpyridine zinc complex of the present invention, R1 and R2 are preferably nitrogen heterocycles or triphenylamine groups. By selecting a unit with a strong electron-donating ability, the energy level of the electron acceptor unit can be effectively adjusted.

[0018] The present invention also provides a method for synthesizing a terpyridine zinc complex, which comprises the following steps:

[0019] 1) reacting 2-bromo-6-acetylpyridine with an aldehyde compound of formula 2 and aqueous ammonia via a Michael addition-ring closure reaction to obtain a terpyridine ligand of formula 3;

[0020]

[0021]

[0022] 2) condensing 2-bromo-6-acetylpyridine with 3,5-di-tert-butylbenzaldehyde to obtain an intermediate of Formula 4; reacting the intermediate of Formula 4 with 2-acetylpyridine and ammonia to obtain a brominated terpyridine compound of Formula 5 through a Michael addition-ring closure reaction; and coupling the brominated terpyridine compound with a boronic acid compound of Formula 6 to obtain a terpyridine ligand of Formula 7;

[0023] 3) performing a coordination reaction between the terpyridine ligand of formula 3, the terpyridine ligand of formula 7 and a zinc salt solution, and then performing an anion exchange reaction to obtain;

[0024]

[0025]

[0026] Wherein, R1 and R2 are independently selected from nitrogen heterocyclic unit, benzene ring unit or triphenylamine unit; further preferably:

[0027] R1 is R2 is

[0028] As a preferred scheme, in step 1), 2-bromo-6-acetylpyridine is subjected to a Michael addition reaction with an aldehyde compound of formula 2 in the presence of a base, and then subjected to a ring closure reaction by adding ammonia water. As a more preferred scheme, the Michael addition reaction is carried out at room temperature for 6-10 hours, and the ring closure reaction is carried out at a temperature of 70-90°C for 16-32 hours. The base is, for example, sodium hydroxide.

[0029] As a preferred scheme, in step 2), 2-bromo-6-acetylpyridine is subjected to a reaction with 3,5-di-tert-butylbenzaldehyde in the presence of a base in an ice bath environment for 8-16 hours. The ice bath environment is generally at a temperature of -5°C to 0°C.

[0030] As a preferred scheme, in step 3), the intermediate of formula 4 is subjected to a Michael addition reaction with 2-acetylpyridine in the presence of a base, and then subjected to a ring closure reaction by adding ammonia water; the Michael addition reaction is carried out at room temperature for 6-10 hours, and the ring closure reaction is carried out at a temperature of 70-90°C for 16-32 hours.

[0031] As a preferred scheme, in step 2), the brominated terpyridine compound is subjected to a coupling reaction with a boronic acid compound of formula 6 in the presence of a base, and the reaction is carried out at a temperature of 75-85°C for 30-60 hours under the catalysis of a palladium catalyst.

[0032] As a preferred scheme, the complexation reaction is carried out at a temperature of 60-70°C for 18-32 hours.

[0033] The application further provides an application of the terpyridine zinc complex as a photosensitizer or a photocatalyst.

[0034] As a preferred scheme, the terpyridine zinc complex has the characteristics of generating singlet oxygen and superoxide radicals under sunlight irradiation.

[0035] The photocatalytic principle of the terpyridine zinc complex of the application is as follows: the photocatalytic process mainly includes two processes of oxygen reduction (ORR) and water oxidation (WOR), wherein the ORR process mainly includes two processes of oxygen→superoxide anion (-0.33V NHE) and oxygen→hydrogen peroxide (0.28V NHE), and in order to balance the electrons and holes, the WOR end is subjected to a two-electron process of water→hydrogen peroxide (1.35V NHE).

[0036] The terpyridine zinc complex provided by the present invention can generate a variety of reactive oxygen species under the excitation of a xenon lamp. At the same time, the terpyridine zinc complex can generate reactive oxygen species such as singlet oxygen and superoxide radicals under sunlight irradiation. The reactive oxygen forms hydrogen peroxide by combining with water or oxygen at a rate that is at the top level in the field. In addition, no sacrificial agent or photosensitizer is required in this system, so it can act as both a photosensitizer and a photocatalyst.

[0037] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0038] The terpyridine zinc complex provided by the present invention uses metallic zinc as the central metal ion. Metallic zinc belongs to the first period transition metal, is cheaper than metals such as platinum, gold, and iridium, and has lower pollution to the environment.

[0039] The terpyridine zinc complex provided by the present invention can generate active oxygen species such as singlet oxygen and superoxide radicals under sunlight irradiation conditions, and exhibits good photosensitivity.

[0040] The preparation method of the terpyridine zinc complex provided by the invention has simple operation and steps, low cost, and is conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Solid UV images of complexes 13 to 16.

[0042] Figure 2 Solid-state transient photoluminescence spectra of complexes 13 to 16 at different temperatures.

[0043] Figures 3-6 The ESR spectra of complexes 13 to 16 under xenon lamp irradiation are shown.

[0044] Figure 7 The figure shows the standard curve of hydrogen peroxide concentration and absorption.

[0045] Figure 8 This is a statistical graph of hydrogen peroxide produced by complexes 13 to 16 after being irradiated under a 10W xenon lamp for a period of time. DETAILED DESCRIPTION

[0046] In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and in detail below in conjunction with preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0047] The substrate raw materials and solvents involved in the following examples are all commercially available products (analytical grade reagents). All reagents used have been purified, dried and pretreated, and the synthesis and processing processes involved use standard anhydrous and oxygen-free techniques.

[0048] 1 H NMR (400 MHz) was performed using CDCl3 and CD3CN as solvents and TMS as the internal standard.

[0049] Multiplicity is defined as follows: s (singlet); d (doublet); t (triplet); q (quartet) and m (multiplet). Absorption intensity is defined as follows.

[0050] Unless otherwise specified, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not necessarily within the scope of protection of the present invention.

[0051] Example 1

[0052] Target product: Compound 1: Compound 2: Compound 3: Compound 4: Compound 5: Compound 6: Compound 1:

[0053] To a solution of 4-pyridinecarboxaldehyde (1 g, 10 mmol) in ethanol (60 mL) were added p-bromoacetophenone (5.97 g, 30 mmol) and NaOH powder (4 g, 100 mmol). After stirring at room temperature for 24 hours, aqueous ammonia (28%, 25 mL) was added, and the resulting mixture was refluxed at 85°C for 20 hours. After cooling to room temperature, the solid was collected by suction filtration and washed with methanol to obtain 3.5 g of the yellow solid product (yield 75%).

[0054] Compound 2:

[0055] Compound 1 (3.82 g, 8.2 mmol) and bis(pinacolato)diboron (2.7 g, 10.6 mmol) were mixed in a 100 mL flask, followed by the addition of 1,4-dioxane (50 mL) and potassium acetate (2.4 g, 24.6 mmol). The system was degassed for 10 minutes, and 1,1'-bis(diphenylphosphino)ferrocenedichloropalladium (351 mg, 0.5 mmol) was added as a catalyst. The mixture was stirred at 85 ° C under nitrogen for 8 hours, cooled to ambient temperature, concentrated in vacuo, and then subjected to column chromatography (alumina) eluted with a mixture of petroleum ether and dichloromethane to purify the product to give 3.15 g (yield 75%) of a white solid.

[0056] Compound 3:

[0057] A solution of 3,5-bis(tert-butyl)benzaldehyde (8.73 g, 40 mmol) was added dropwise to a stirred emulsion containing 2-acetyl-6-bromopyridine (8.0 g, 40 mmol) and potassium hydroxide (1.8 g, 32 mmol) in 150 mL of methanol. After stirring in an ice bath for 12 hours, the resulting pale yellow solid was filtered, washed with cold methanol, and dried under vacuum to give 10 g of the product as a white solid (55% yield).

[0058] Compound 4:

[0059] To a solution of compound 3 (4 g, 10 mmol) in ethanol (60 mL) were added 2-acetylpyridine (3.63 g, 30 mmol) and sodium hydroxide powder (4 g, 100 mmol). After stirring at room temperature for 24 hours, aqueous ammonia solution (28%, 25 mL) was added, and the resulting mixture was refluxed for 20 hours. After cooling to room temperature, the solid was collected by suction filtration and washed with methanol to obtain 2.042 g of the product as a white solid (yield 43.7%).

[0060] Compound 5:

[0061] To the flask containing compound 2 (500mg, 1.38mmol) and (3-(trimethylsilyl)phenyl)boric acid (808mg, 4mmol) and sodium hydroxide (0.2g, 50.00mmol) was added a mixed solvent of tetrahydrofuran / water (8:1, v / v) (48mL). Tetrakis triphenylphosphine palladium (0.2g, 0.18mmol) was then added, the pumping system was backfilled with nitrogen. The mixture was refluxed under nitrogen for 3 days. After cooling to 25°C, the mixture was extracted with dichloromethane, and the combined organic extracts were evaporated in vacuo to dryness to obtain a residue, which was washed with methanol and then subjected to column chromatography (aluminum oxide, dichloromethane / methanol=100:1). The main portion was then recrystallized from a chloroform / methanol mixture to obtain (77%) compound 3 as a white solid 0.569g (0.71mmol).

[0062] Compound 6:

[0063] Liquid bromine (3 ml) was added to a solution of compound 5 (500 mg) in dichloromethane (50 mL), and the mixture was stirred at 25° C. for 24 hours. Then, sodium bisulfite (5 g) and sodium bicarbonate (5 g) were added to adjust the pH to a weak alkaline state, and the organic phase was extracted. The mixture was extracted with dichloromethane, and the combined organic extracts were evaporated to dryness in vacuo to obtain a residue, which was washed with methanol and eluted with methanol to obtain a white solid (1.55 g, 35.7%). Compound 1: 1H NMR (400MHz, CDCl3, ppm): δ=8.73–8.67(m,2H),8.03–7.93(m,4H),7.77(s,2H),7.61–7.51(m,6H).13C NMR(101MHz,Chloroform-d)δ156.93,150.77,147.88,146.07,137.71,132.02,128.65,124.08,121.61,116.70.ESI-MS(466.18calcd.For C 22 H 14 Br2N2):m / z=466.9016[M+H + ] + (calcd.m / z=467.18).Compound 2: 1 HNMR (400MHz, CDCl3, ppm): δ = 8.71 (d, J = 6.1Hz, 2H), 8.12 (d, J = 8.1Hz, 4H), 7.89 (d, J = 7.8Hz, 4H), 7.85 (s, 2H), 7.61 (d, J = 6.1Hz, 2H), 1.31 (s, 24H).13C NMR(101MHz,Chloroform-d)δ156.86,149.38,146.36,145.61,140.43,134.24,127.81,126.13,125 .31,125.28,120.77,120.75,116.17,82.94,82.04,23.87,23.80,23.51.ESI-MS(560.31calcd.For C 34 H 38 B2N2O2):m / z=561.3250[M+H + ] + (calcd.m / z=561.31).

[0064] Compound 3: 1H NMR (400MHz, CDCl3, ppm): δ=8.20–8.10(m,2H),8.01(d,J=16.0Hz,1H),7.80–7.67(m,2H),7.56(dd,J=12.2,1.8Hz,3H),1.40(s,18H).13C NMR(101MHz,Chloroform-d)δ187.99,155.32,151.46,147.27,141.30,139.28,1 34.27,131.46,125.51,123.40,121.83,119.56,31.42.ESI-MS(400.36calcd.For C 22 H 26 BrNO): m / z=402.1026[M+H + ] + (calcd.m / z=401.36).

[0065] Compound 4: 1 H NMR (400MHz, CDCl3, ppm): δ = 8.66 (d, J = 6.6Hz, 1H), 8.60 (s, 1H), 8.54 (d, J = 8.0Hz, 3H), 7.79 (t, J = 7. 7Hz,1H),7.63(t,J=7.8Hz,1H),7.52(s,2H),7.49–7.41(m,2H),7.31–7.24(m,1H),1.34(s,18H).13C NMR(101MHz,Chloroform-d)δ157.70,156.26,155.90,154.17,152.30,151.49,149.21,141.63,139.11,138.3 1,136.84,128.00,123.83,123.15,121.79,121.41,120.11,120.09,120.01,31.61.ESI-MS(500.48calcd.ForC 29 H 30 BrN3): m / z=502.1694[M+H + ] + (calcd.m / z=501.48).

[0066] Compound 5: 1H NMR(400MHz,Chloroform-d)δ8.85(d,J=1.7Hz,1H),8.66(d,J=5.7Hz,1H),8.60(d,J=6.6Hz,2H),8.54(d,J=8.8Hz,1H),8.10(d,J=8.1Hz,2H),7.93–7.81(m,2H),7.76(d,J=7.9Hz,1H),7.63(d,J=1.8Hz,2H),7.58(d,J=8.1Hz,2H),7.49(t,1H),7.33–7.28(m,1H),1.37(s,18H),0.25(s,9H).13C NMR(101MHz,Chloroform-d)δ155.56,155.31,155.07,154.98,154.64,150.79,150.45,148.07,140.51,138.66,137.52,136.56,135.88,132.70,125.15,122.69,122.02,120.78,120.52,119.22,118.89,118.66,118.43,30.53.ESI-MS(569.87calcd.For C 38 H 43 N3Si):m / z=570.3140[M+H + ] + (calcd.m / z=570.87).

[0067] 化合物6: 1H NMR (400 MHz, Chloroform-d) δ 8.83 (d, J = 1.7 Hz, 1H), 8.70 (d, J = 4.8 Hz, 1H), 8.66 - 8.56 (m, 3H), 8.02 (d, J = 8.3 Hz, 2H), 7.87 (dt, J = 15.3, 7.8 Hz, 2H), 7.73 (d, J = 7.9 Hz, 1H), 7.61 (d, J = 1.7 Hz, 2H), 7.58 - 7.46 (m, 3H), 7.31 (dd, J = 11.8, 5.5 Hz, 1H), 1.37 (s, 18H).13C NMR (101 MHz, Chloroform-d) δ 155.42, 154.97, 154.73, 154.70, 153.96, 150.73, 150.48, 148.09, 137.41, 137.10, 136.75, 135.85, 130.78, 127.40, 122.73, 122.44, 122.08, 120.74, 120.46, 118.87, 118.84, 118.78, 118.46, 30.51. ESI-MS (576.58 calcd. For C 35 H 34 BrN3): m / z = 578.2301 [M+H + ] + (calcd. m / z = 577.58).

[0068] Example 2

[0069] Target product: Compound 7: Compound 8: Compound 9: Compound 10: Compound 11: Compound 12: Compound 7: To a solution of isophthalaldehyde (1.34 g, 10 mmol) in ethanol (60 mL) was added 2-acetylpyridine (6.057 g, 50 mmol) and sodium hydroxide powder (4 g, 100 mmol). After stirring at room temperature for 24 h, an ammonia solution (28%, 25 mL) was added and the resulting mixture was refluxed for 20 h. After cooling to room temperature, the solid was collected by suction filtration and washed with methanol to give the white solid product 2.042 g (yield 43.7%).

[0070] Compound 8: To a solution of 2,6-pyridinedicarboxaldehyde (1.34 g, 10 mmol) in ethanol (60 mL) was added 2-acetylpyridine (6.057 g, 50 mmol) and sodium hydroxide powder (4 g, 100 mmol). After stirring at room temperature for 24 h, an aqueous ammonia solution (28%, 25 mL) was added and the resulting mixture was refluxed for 20 h. After cooling to room temperature, the solid was collected by suction filtration and washed with methanol to give the product as a white solid 2.3 g (yield 43%).

[0071] Compound 9: To a flask containing 2,6-dibromopyridine (1 g, 4.2 mmol) and (4-([2,2':6',2'-pyridine]-4'-yl)phenyl)boronic acid (4.5 g, 12.6 mmol) and potassium carbonate (2.76 g, 20 mmol) was added a mixed solvent of tetrahydrofuran / water (10:1, v / v) (44 mL). Then tetrakis(triphenylphosphine)palladium (0.208 g, 0.18 mmol) was added, the system was pumped and backfilled with nitrogen. The mixture was refluxed under nitrogen for 3 days. After cooling to 25 °C, the mixture was washed with methanol and water to give (77%) 2.5 g (3.6 mmol) of a white solid.

[0072] Compound 10: To a flask containing compound 6 (200 mg, 0.37 mmol) and 4'-bromo-2,2':6',2'-terpyridine (550 mg, 1.1 mmol) and potassium carbonate (690 mg, 5 mmol) was added a mixed solvent of tetrahydrofuran / water (10:1, v / v) (44 mL). Then tetrakis(triphenylphosphine)palladium (0.208 g, 0.18 mmol) was added, the system was pumped and backfilled with nitrogen. The mixture was refluxed under nitrogen for 3 days. After cooling to 25 °C, the mixture was extracted with dichloromethane and the combined organic extracts were evaporated to dryness in vacuo to give a residue which was washed with methanol to give (77%) 0.569 g (0.71 mmol) of a yellow solid.

[0073] Compound 11 : To a flask containing compound 2 (1.25 g, 2.5 mmol) and phenyl bis-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxolan-2-yl)-phenyl]-amine (500 mg, 1.005 mmol) and potassium carbonate (6.9 g, 5 mmol) was added a mixed solvent of tetrahydrofuran / water (8:1, v / v) (48 mL). Then tetrakis(triphenylphosphine)palladium (0.2 g, 0.18 mmol) was added, the system was pumped and backfilled with nitrogen. The mixture was refluxed under nitrogen for 3 days. After cooling to 25 °C, the mixture was extracted with dichloromethane and the combined organic extracts were evaporated to dryness in vacuo to give a residue which was washed with methanol and then subjected to column chromatography (alumina, dichloromethane / petroleum ether = 1 :4) as a white solid: 0.800 g (0.7 mmol).

[0074] Compound 12: A mixed solvent (48 mL) of tetrahydrofuran / water (8:1, v / v) was added to a flask containing 4 (1.44 mg, 2.5 mmol) and phenylbis-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxolane-2-yl)-phenyl]-amine (500 mg, 1.005 mmol) and potassium carbonate (690 mg, 5 mmol). Tetrakis triphenylphosphine palladium (0.2 g, 0.18 mmol) was then added, the system was pumped and backfilled with nitrogen. The mixture was refluxed under nitrogen for 3 days. After cooling to 25 ° C, the mixture was extracted with dichloromethane, and the combined organic extracts were evaporated to dryness in vacuo to give a residue, which was washed with methanol and then subjected to column chromatography (aluminum oxide, dichloromethane / petroleum ether=1:4) to give 0.569 g (0.71 mmol) of a white solid.

[0075] Compound 7: 1 H NMR (400MHz, Chloroform-d) δ = 8.75 (s, 4H), 8.67 (d, J = 3.0Hz, 4H), 8.63 (d, J = 7.9Hz, 4H), 8.2 8(s,1H),7.91(d,J=7.7Hz,2H),7.83(t,J=6.8Hz,4H),7.60(t,J=7.7Hz,1H),7.29(t,4H).13C NMR(101MHz,Chloroform-d)δ156.18,156.00,150.18,149.16,139.57,136.92,129.59,128.17,126.21,123.89,121.44,119.25.ESI-MS(540.63calcd.For C 35 H 23 N7): m / z = 541.22 [M+H + ] + (calcd.m / z=541.63).

[0076] Compound 8: 1H NMR (400 MHz, Chloroform-d) δ = 9.17 (s, 4H), 8.69 (d, J = 3.9 Hz, 4H), 8.60 (d, J = 7.9 Hz, 4H), 8.04 (d, J = 7.8 Hz, 2H), 7.90 (t, 1H), 7.79 (dd, J = 7.7, 1.8 Hz, 4H), 7.31 - 7.25 (m, 4H).13C NMR (101 MHz, Chloroform-d) δ 156.24, 156.13, 155.09, 149.16, 148.46, 137.92, 136.94, 123.86, 121.48, 121.28, 118.95. ESI-MS (541.62 calcd. For C 36 H 24 N6: m / z = 542.20 [M+H + ] + (calcd. m / z = 542.62).

[0077] Compound 9: 1 H NMR (400 MHz, Chloroform-d) δ = 8.74 (s, 4H), 8.68 (d, J = 7.6 Hz, 1H), 8.61 (d, J = 10.0 Hz, 1H), 8.26 (d, 2H), 8.02 (d, J = 8.4 Hz, 3H), 7.83 (d, J = 1.9 Hz, 3H), 7.31 (dd, J = 7.5, 4.8 Hz, 3H).13C NMR (101 MHz, Chloroform-d) δ 156.27, 156.01, 149.16, 136.97, 127.75, 127.57, 123.89, 121.46, 118.90. ESI-MS (693.81 calcd. For C 47 H 31 N 7) : m / z = 694.19 [M+H + ] + (calcd. m / z = 694.81).

[0078] Compound 10: 1H NMR(400MHz,Chloroform-d)δ=8.79–8.74(m,6H),8.70(ddd,J=4.8,1.8,0.9Hz,4H),8.63(dt,J=7.9,1.1Hz,4H),8.31(d,4H),8.04(d,4H),7.94(s,2H),7.84(td,J=7.7,1.8Hz,4H),7.69–7.63(m,2H),7.31(ddd,J=7.6,4.8,1.3Hz,4H).13CNMR(101MHz,Chloroform-d)δ156.41,155.22,155.05,149.72,148.66,148.16,138.52,138.44,135.90,126.82,126.67,122.88,120.72,120.41,117.83,116.06.ESI-MS(770.90calcd.For C 52 H 34 N8):m / z=771.31[M+H + ] + (calcd.m / z=771.90).

[0079] 化合物11: 1H NMR (400 MHz, Chloroform-d) δ = 8.83 (d, J = 1.6 Hz, 2H), 8.71 - 8.66 (m, 2H), 8.63 (dt, J = 7.6, 1.3 Hz, 4H), 8.52 (dd, J = 7.7, 0.8 Hz, 2H), 8.07 - 8.00 (m, 4H), 7.85 (td, J = 7.7, 5.3 Hz, 4H), 7.70 (dd, J = 7.9, 0.9 Hz, 2H), 7.59 (d, J = 1.8 Hz, 4H), 7.45 (t, J = 1.8 Hz, 2H), 7.30 (ddd, J = 7.5, 4.8, 1.2 Hz, 2H), 7.24 (dd, J = 8.5, 7.2 Hz, 2H), 7.19 - 7.13 (m, 8H), 7.03 (t, 2H), 1.32 (s, 36H).13C NMR (101 MHz, Chloroform-d) δ 156.42, 156.11, 155.91 (d, J = 3.8 Hz), 151.89, 151.45, 148.97, 148.39, 147.21, 138.51, 137.64, 137.11, 133.75, 129.41, 127.94, 124.93, 123.99, 123.78, 123.58, 123.05, 121.80, 121.61, 119.95, 119.73, 119.53, 119.18, 31.56. ESI-MS (calcd. for C 76 H 73 N7): m / z = 1084.44 [M+H + ] + (calcd. m / z = 1085.47). Compound 12: 1 H NMR (400 MHz, Chloroform-d) δ = 8.97 (d, J = 1.7 Hz, 2H), 8.74 (m, J = 4.9, 1.8, 0.9 Hz, 2H), 8.70 (dd, J = 8.3, 1.3 Hz, 4H), 8.62 (d, J = 7.6, 1.0 Hz, 2H), 8.29 (d, J = 8.4 Hz, 4H), 8.01 - 7.85 (m, 6H), 7.77 - 7.68 (m, 8H), 7.64 - 7.54 (m, 6H), 7.41 - 7.29 (m, 4H), 7.26 - 7.20 (m, 6H), 7.09 (t, J = 7.3 Hz, 1H), 1.45 (s, 36H). 13C NMR(101MHz,Chloroform-d)δ156.51,156.06,155.93,155.82,155.65,151.80, 151.50,149.09,147.44,147.24,141.23,138.57,137.73,137.68,137.00,134.8 0,129.46,127.89,127.33,126.94,124.85,124.22,123.78,123.41,123.10,121 .87,121.57,120.02,119.97,119.57,119.48,31.60.ESI-MS(1236.67calcd.For C 88 H 81 N7): m / z = 1237.68 [M+H + ] + (calcd.m / z=1237.67).

[0080] Example 3

[0081] Synthesis of complexes 13-16:

[0082]

[0083] Where X is PF6 -

[0084] Complex 13: R1 is R2 is Complex 14: R1 is R2 is Complex 15: R1 is R2 is Complex 16: R1 is R2 is Complex 13:

[0085] Formula 7 (50 mg, 92.5 μmol) and Formula 11 (100.3 mg, 92.5 μmol) were added to a mixed solvent of chloroform (20 mL) and methanol (20 mL), followed by a solution of zinc nitrate hexahydrate (55.04 mg, 185 μmol) in methanol (15 mL). After stirring the mixture at 65°C for 15 hours, an excess of ammonium hexafluorophosphate was added to precipitate the complex, which was then filtered, washed with water, and dried in vacuo. 130 mg (55.6 μmol) of the desired compound was obtained as a yellow solid (92%).

[0086] Complex 14:

[0087] To a mixture solvent of chloroform (20 mL) and methanol (20 ml) was added Formula 8 (50 mg, 92.48 pmol) and Formula 11 (100.3 mg, 92.5 pmol), followed by a solution of zinc nitrate hexahydrate (55.04 mg, 185 pmol) in methanol (21.765 mL). After stirring the mixture at 65 °C for 15 hours, excess hexafluorophosphoric acid was added to precipitate the complex, followed by filtration, washing with water, and then drying under vacuum. The desired yellow solid (92%) was obtained: 130 mg (56 pmol).

[0088] Complex 15:

[0089] To a mixture solvent of chloroform (34 mL) and methanol (26 mL) was added Formula 9 (56.10 mg, 80.8 pmol) and Formula 12 (100 mg, 80.0 pmol), followed by a solution of zinc nitrate hexahydrate (48.1 mg, 161.7 pmol) in methanol (10 mL). After stirring the mixture at 60 °C for 15 hours, excess hexafluorophosphoric acid was added to precipitate the complex, followed by filtration, washing with water, and then drying under vacuum. The desired yellow solid complex (93%) was obtained: 130 mg (49.23 pmol).

[0090] Complex 16:

[0091] To a mixture solvent of chloroform (21 mL) and methanol (23 mL) was added Formula 10 (62.288 mg, 80.8 pmol) and Formula 12 (100 mg, 80.0 pmol), followed by a solution of zinc nitrate hexahydrate (48.1 mg, 161.7 pmol) in methanol (10 mL). After stirring the mixture at 65 °C for 15 hours, excess hexafluorophosphoric acid was added to precipitate the complex, followed by filtration, washing with water, and then drying under vacuum. The desired yellow solid complex (80%) was obtained: 130 mg (48 pmol).

[0092] Complex 13: 1H NMR (400 MHz, CD3CN) δ = 9.06 (s, 2H), 8.96 (s, 2H), 8.86 (s, 4H), 8.78 (d, J = 8.0 Hz, 2H), 8.72 (d, J = 8.1 Hz, 2H), 8.61 (d, J = 8.0 Hz, 4H), 8.40 (d, J = 9.4 Hz, 2H), 8.31 (s, 1H), 8.21 (dd, J = 16.5, 8.8 Hz, 9H), 8.01 (d, J = 1.7 Hz, 4H), 7.93 - 7.82 (m, 6H), 7.66 (d, J = 6.2 Hz, 2H), 7.49 (dd, J = 7.6, 5.2 Hz, 3H), 7.44 - 7.23 (m, 7H), 6.55 (d, J = 8.4 Hz, 4H), 6.41 (dd, J = 12.8, 8.0 Hz, 6H), 1.55 (s, 36H). ESI-MS (2335.1 calcd. For C 112 H 97 Zn2F 24 N 13 P4): m / z 439.0247 [M - 4PF6] 4+ (calcd m / z: 439.0259); m / z 633.6937 [M - 4PF6] 3+ (calcd m / z: 633.6946).

[0093] Complex 14: 1 H NMR (400 MHz, CD3CN), δ = 9.26 (s, 4H), 9.08 (s, 2H), 8.95 (s, 2H), 8.83 (d, J = 7.0 Hz, 2H), 8.76 - 8.58 (m, 9H), 8.36 - 8.18 (m, 6H), 8.13 (td, J = 7.9, 1.6 Hz, 2H), 8.02 (d, J = 1.8 Hz, 4H), 7.95 - 7.80 (m, 6H), 7.62 (d, J = 4.6 Hz, 2H), 7.50 (ddd, J = 7.7, 5.0, 1.0 Hz, 4H), 7.45 - 7.32 (m, 4H), 7.31 - 7.15 (m, 3H), 6.47 (d, J = 8.6 Hz, 4H), 6.32 (td, J = 6.4, 2.1 Hz, 6H), 1.55 (s, 36H). ESI-MS (2336.1 calcd. For C 111 H 96 Zn2F 24 N 14 P4): m / z 439.2625 [M - 4PF6] 4+(calcd m / z: 439.2636); m / z 634.0123 [M-4PF6 ]3+ (calcd m / z: 634.0135).

[0094] Complex 15: 1 H NMR (400 MHz, CD3CN) δ = 9.11 (s, 2H), 9.01 - 8.85 (m, 4H), 8.67 (m, J = 8.1 Hz, 10H), 8.60 (d, J = 8.4 Hz, 4H), 8.37 (t, J = 7.9 Hz, 2H), 8.26 (t, J = 7.8 Hz, 4H), 8.19 (d, J = 4.7 Hz, 3H), 8.13 - 7.98 (m, 10H), 7.95 - 7.84 (m, 6H), 7.63 - 7.46 (m, 6H), 7.34 (d, J = 4.9 Hz, 4H), 7.25 (d, J = 3.3 Hz, 4H), 7.12 (d, J = 8.0 Hz, 4H), 7.02 (t, J = 7.3 Hz, 1H), 6.95 - 6.79 (m, 8H), 6.53 (d, J = 8.0 Hz, 4H), 1.56 (s, 36H). ESI-MS (2640.48 calcd. For C 135 H 112 Zn2F 24 N 14 P4): m / z 515.4154 [M-4PF6] 4+ (calcd m / z: 515.4166); m / z 735.5494 [M-4PF6] 3+ (calcd m / z: 735.5505).

[0095] Complex 16: 1H NMR (400 MHz, CD3CN). δ = 9.11 (s, 2H), 8.99 (d, J = 6.7 Hz, 2H), 8.95 - 8.90 (m, 4H), 8.68 (t, J = 7.9 Hz, 14H), 8.52 (d, J = 9.3 Hz, 4H), 8.37 (t, J = 7.9 Hz, 2H), 8.27 (t, J = 8.6 Hz, 4H), 8.08 (dd, J = 15.6, 8.2 Hz, 6H), 8.02 (d, J = 1.8 Hz, 4H), 7.96 - 7.82 (m, 6H), 7.54 (q, J = 7.1, 6.3 Hz, 6H), 7.34 (d, J = 8.5 Hz, 4H), 7.28 (dd, J = 10.9, 4.1 Hz, 4H), 7.13 (d, J = 7.8 Hz, 4H), 6.92 (d, J = 7.2 Hz, 3H), 6.86 (d, J = 8.6 Hz, 4H), 6.80 (d, J = 9.7 Hz, 2H), 6.53 (d, J = 8.1 Hz, 4H), 1.55 (s, 36H). ESI-MS (2717.57 calcd. For C 140 H 115 Zn2F 24 N 15 P4): m / z 534.6891 [M-4PF6] 4+ (calcd m / z: 534.6902); m / z 762.6291 [M-4PF6] 3+ (calcd m / z: 762.6304).

[0096] Example 4

[0097] Performance test of complexes 13-16:

[0098] Hydrogen peroxide standard curve drawing:

[0099] 0.058 mM, 0.113 mM, 0.165 mM, 0.215 mM and 0.265 mM concentrations of water 2 were mixed with 0.4 M potassium iodide and 0.1 M potassium hydrogen phthalate respectively, and then the absorption peak at 350 nm was detected, and the standard curve of the corresponding concentration and ultraviolet absorption characteristic peak absorption was drawn.

[0100] UV-Vis spectrum experiment:

[0101] 0.5 mL of the reaction solution was taken and diluted to 3 mL with 2.5 mL of water, then 1 mL of 0.4 mol / L potassium iodide and 0.1 mol / L potassium hydrogen phthalate were added. After mixing, the reaction was placed for half an hour, and the ultraviolet absorption spectrum test was carried out, and the 350 nm absorption peak was detected.

[0102] Detection of active oxygen:

[0103] The complexes 13, 14, 15 and 16 were placed in aqueous solution / methanol solution under the condition of 200 mWcm -2 of light intensity. At the same time, DMPO, a capture agent of TEMP, was added. The EPR spectra under light and dark conditions were detected respectively. It was detected that the complex 16 generated two types of active oxygen, singlet oxygen and superoxide free radicals, under light condition.

[0104] The solid ultraviolet spectra of the complexes 13-16 are shown in the following figure. Figure 1 From the figure, it can be seen that the complexes have a wide absorption at 200-500 nm.

[0105] The solid transient photoluminescence spectra of the complexes 13-16 at different temperatures are shown in the following figure. Figure 2 From the figure, it can be seen that the complexes 13-16 have a long lifetime, which means that the complexes 13-16 have potential properties as photosensitizers.

[0106] The paramagnetic resonance spectra (ESR) of the complexes 13-16 under xenon lamp irradiation are shown in the following figure. Figures 3-5 From the figure, it can be seen that active oxygen substances such as singlet oxygen, superoxide free radicals and hydroxyl free radicals are generated under light excitation.

[0107] The standard curve of hydrogen peroxide concentration and absorption is shown in the following figure. Figure 6

[0108] The statistics of hydrogen peroxide generated by the complexes 13-16 after irradiation under a 10W xenon lamp for a period of time are shown in the following figure. Figure 7 From the figure, it can be seen that the above complexes have excellent photocatalytic ability.

[0109] It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles and method processes of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.​

Claims

1. A terpyridine zinc complex, characterized in that: It has the molecular structure shown in formula 1: Formula 1 in, X is PF6 - ; R1 is 、 、 or ; R2 is or .

2. The use of a terpyridine zinc complex according to claim 1, characterized in that: Used as a photosensitizer.

3. The use of a terpyridine zinc complex according to claim 2, characterized in that: The terpyridine zinc complex generates singlet oxygen and superoxide free radicals under sunlight irradiation.

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