Interlocking conjugated aromatic-anti-aromatic bicyclic porphyrins and methods of making the same

Abstract

The application discloses an interlocked conjugated aromatic-anti-aromatic bicyclic porphyrin and a preparation method thereof; a long-chain linear heptapyrrolidine precursor is efficiently constructed through a [4+3] module method, and based on the flexible and soft molecular structure, a novel interlocked conjugated aromatic-anti-aromatic bicyclic porphyrin is synthesized through a one-pot method, so that the complicated steps such as the necessary porphyrin monomer structure modification and metal catalytic coupling in the synthesis of a traditional bicyclic porphyrin are avoided; and different from the traditional bicyclic porphyrin, the interlocked conjugated aromatic-anti-aromatic bicyclic porphyrin constructed in the application can further chelate high-valence metal ions to generate a stable bicyclic porphyrin monocopper complex II, and a novel isoporphyrin compound with a successfully constructed pi conjugated path and adjustable absorption characteristics is constructed.

Description

Technical Field

[0001] This invention relates to the field of porphyrin and isoporphyrin chemistry, specifically to an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin and its preparation method. Background Technology

[0002] Porphyrins are conjugated aromatic macrocyclic compounds with 18π electrons, possessing unique photoelectric properties and wide applications in luminescent materials, solar cells, chemical sensors, catalysis, and other fields. Isoporphyrins, obtained by altering the parent structure of porphyrins, such as misaligned porphyrins (Chem.Rev.2022,122,8313-8437), condensed porphyrins (Chem.Rev.2017,117,2785-2838), and extended porphyrins (Chem.Rev.2017,117,2584–2640), often exhibit unique structures and rich and interesting properties. As the most important and widely studied class of isoporphyrins, extended porphyrins possess a rich variety of interesting molecular conformations, multiple redox states, and unique aromatic properties.

[0003] The shortcomings of existing technology:

[0004] Bicyclic porphyrins, as a special type of extended porphyrin structure, contain two identical or different ring cavities within their molecules, exhibiting local or global conjugated circuits and displaying more diverse aromatic, electronic, and coordination properties. Currently, the structures of bicyclic porphyrins are often quite complex, and the synthetic steps are rather cumbersome, with related research still in its early stages. The conventional synthetic method for bicyclic porphyrins is metal-catalyzed coupling reactions, which require the construction of porphyrin functionalized products, such as halogenated and borate ester porphyrins. The selectivity and yield of the reaction are often unsatisfactory, severely restricting the performance research and application of bicyclic porphyrins. Summary of the Invention

[0005] The purpose of this invention is to provide an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin, wherein the structural formula of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin compound I is:

[0007]

[0008] Preferably, the structural formula of the 18π aromatic bicyclic porphyrin monocopper complex II is:

[0009]

[0010] This invention also provides an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin and its preparation method, the preparation method comprising the following steps:

[0011] S1. Preparation of linear heptapyrrolidine I-1: At room temperature, the tetrapyrrole monoacylated raw material is reduced with sodium borohydride in a mixed solution of tetrahydrofuran or methanol. After the reaction is completed, water is added to quench the reaction. The mixture is then extracted, washed, dried, and the solvent is evaporated to obtain tetrapyrrole monool. No purification is required.

[0012] S2. In an inert gas environment, the tetrapyrrolidine monool and tripyrrolidine raw materials obtained in step S1 are dissolved in dichloromethane, followed by condensation with trifluoroacetic acid. After the reaction is complete, triethylamine is added to quench the reaction, the solvent is directly evaporated, and the mixture is purified to obtain intermediate compound I-1. The structural formula of intermediate I-1 is as follows:

[0013]

[0014] S3. At room temperature, I-1 was dissolved in DCM, DDQ was added for oxidation, and the mixture was heated under reflux for 72 hours. Then, the mixture was extracted, washed, dried, and purified sequentially to obtain intermediate I-2, a blue-purple solid. DDQ was 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. The structural formula of intermediate I-2 is as follows:

[0015]

[0016] S4. At room temperature, intermediate I-2 was dissolved in DCM, DDQ was added for oxidation, and then the mixture was extracted, washed, dried and purified to obtain the target compound I as a dark green solid.

[0017] S5. At room temperature, compound I was dissolved in DCM, copper chloride dihydrate was added, and then extracted, washed, dried and purified sequentially to obtain a dark olive-colored solid compound II.

[0018] Preferably, in step S2, the molar mass ratio of the intermediate tetrapyrrolidine monool, tripyrrolidine, and trifluoroacetic acid is 1:2.5-3:0.3-0.5, and the reaction time is 1-2 hours.

[0019] Preferably, in step S3, the molar mass ratio of intermediate I-1 to DDQ is 1:6 to 7, the reaction time is 64 to 72 hours, and heating under reflux is required.

[0020] Preferably, in step S4, the molar mass ratio of intermediate I-2 to DDQ is 1:1 to 3, and the reaction time is 1 to 2 hours.

[0021] Preferably, in step S5, the molar mass ratio of compound I to copper chloride dihydrate is 1:1 to 2, and the reaction time is 15 to 30 minutes.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] This invention discloses an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin and its preparation method. A long-chain linear heptapyrrolidine precursor was efficiently constructed using a [4+3] module method. Based on its flexible molecular structure, a novel interlocked conjugated aromatic-antiaromatic bicyclic porphyrin was synthesized in a "one-pot" manner, avoiding the cumbersome steps of porphyrin monomer structure modification and metal-catalyzed coupling required in traditional bicyclic porphyrin synthesis. Furthermore, unlike traditional bicyclic porphyrins, the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin constructed in this invention can further chelate high-valence metal ions to generate stable bicyclic porphyrin single-copper complex II, successfully constructing a novel isoporphyrin compound with tunable π-conjugated pathways and absorption characteristics. Attached Figure Description

[0024] Figure 1 This is a synthetic route diagram for the linear heptapyrrolidine intermediate I-1 of the present invention;

[0025] Figure 2 This is a synthetic route diagram of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin I and its complex II of the present invention;

[0026] Figure 3 The absorption spectra of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin I, its intermediate I-2, and its complex II are shown in the present invention.

[0027] Figure 4 This is the 1H NMR spectrum (298K) of the linear heptapyrrolidine intermediate I-1 of the present invention;

[0028] Figure 5 The 1H NMR spectrum (298K) of intermediate I-2 of this invention is shown below.

[0029] Figure 6 The 1H NMR spectrum (298K) of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin I of this invention is shown.

[0030] Figure 7 The 1H NMR spectrum (298K) of the bicyclic porphyrin complex II of this invention is shown.

[0031] Figure 8 This is a schematic diagram of the single-crystal structure of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin I of the present invention;

[0032] Figure 9 This is a schematic diagram of the single-crystal structure of the bicyclic porphyrin complex II of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integrated connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0037] Example 1

[0038] This invention provides a technical solution for interlocked conjugated aromatic-antiaromatic bicyclic porphyrins: the structural formula of interlocked conjugated aromatic-antiaromatic bicyclic porphyrin compound I is as follows:

[0039]

[0040] The structural formula of 18π aromatic bicyclic porphyrin monocopper complex II is:

[0041]

[0042] Example 2

[0043] Please see Figure 1-9As shown, this invention provides a method for preparing interlocked conjugated aromatic-antiaromatic bicyclic porphyrins, which includes the following steps:

[0044] S1. In a 250 mL round-bottom flask, add a mixed solution of tetrapyrrolidine monoacylation starting material P4-a (5.80 g, 5.82 mmol) and tetrahydrofuran or methanol (80 / 8 mL (v / v)). Stir at room temperature for 15 minutes, then slowly add sodium borohydride (2.21 g, 58.2 mmol) in three portions and react for 60 minutes each time. Monitor the reaction of the starting material by TLC until complete. Quench the reaction with saturated ammonium chloride aqueous solution, extract with dichloromethane (4 × 30 mL), dry with anhydrous sodium sulfate, combine the organic phases, and evaporate to dryness at 30 °C to obtain a yellow oily tetrapyrrolidine monool P4-a-OH, which can be directly added to the next reaction without purification.

[0045] S2. The tetrapyrrolidine monool P4-a-OH obtained in step S1 and the tripyrrolidine raw material P3 (9.08 g, 16.3 mmol) were added to a 1 L round-bottom flask, and then dissolved in dichloromethane (450 mL). The mixture was stirred at room temperature for 15 minutes, and then trifluoroacetic acid (177 μL, 2.33 mmol) was slowly added. The mixture was stirred in the dark for about 1–2 hours. TLC was used to monitor the reaction of the monool raw material 4-a-OH until complete. The reaction was quenched by adding triethylamine (328 μL, 2.33 mmol). After 30 minutes, the mixture was directly evaporated to dryness. The crude product was separated by column chromatography using petroleum ether / dichloromethane = 4 / 1 as the eluent to obtain a yellow foamy intermediate I-1 (2.86 g, 32%). The 1H NMR, 1C NMR, and mass spectrometry data of intermediate I-1 are as follows: 1 H NMR (400MHz, CDCl3, ppm) δ: 8.14 (s, 2H), 8.03 (s, 5H), 6.70 (s, 2H), 6.12 (s, 2H), 5.97 (s, 2H), 5.87 (t, J = 5.4Hz, 10H), 5.80 (s, 2H), 5.72 (s, 4H). 13 CNMR (101MHz, CDCl3, ppm) δ:171.6,146.2,143.8,141.9,139.4,139.2,136.9,136.7,136.5,128 .9,128.5,128.3,127.8,118.4,118.3,115.5,115.4,108.9,108.1,107.8,33.2.HRMS:m / z;[M+K] + :calcd for C 70 H 29 F 30 N7K:1576.1642; Found:1576.1666.

[0046] The structural formula of intermediate I-1 is:

[0047]

[0048] S3. Intermediate I-1 (255 mg, 0.166 mmol) was added to a 500 mL round-bottom flask, and then dissolved in dichloromethane (250 mL). After stirring at room temperature for 10 minutes, DDQ (245 mg, 1.08 mmol) was dissolved in dichloromethane (100 mL) and slowly added to the reaction system over approximately 30 minutes. After stirring at room temperature for 4 hours, the mixture was transferred to a heating module and heated under reflux for 64–72 hours. The reaction was then quenched with water, washed with brine, and extracted with dichloromethane (4 × 50 mL). The organic phase was dried over anhydrous sodium sulfate using a short alumina column, and the solvent was evaporated under reduced pressure to obtain the crude product. The crude product was separated by column chromatography using petroleum ether / dichloromethane = 3 / 1 (v / v) as the eluent to obtain compound I-2 (38 mg, 15%) as a blue-violet solid. The 1H NMR, 1C NMR, mass spectrometry, and absorption spectra of intermediate I-2 are as follows: 1 H NMR(600MHz,acetone-d6,ppm)δ:11.76(s,1H),8.32(s,2H),8.06(s,2H),7.42(d ,J=3.1Hz,2H),7.24(s,2H),6.59(s,2H),6.45(s,2H),5.91(s,2H),4.59(s,2H). 13 C NMR (151MHz, CDCl3, ppm) δ: 159.6, 150.4, 149.0, 146.9 (d, 1 J CF =190H Z *),146.1(d, 1 J CF =250H Z *),145.1(d, 1 J CF =250H Z *), 142.0(d, 1 J CF =258H Z *), 140.4, 140.3, 138.2(d, 1 J CF =253H Z *), 137.8(d, 1 J CF =253H Z *), 137.3(d, 1 J CF =252H Z*),134.2,132.5,130.3,128.5,127.7,123.3,121.2,113.3,113.0(d, 1 J CF =280H Z *),111.5(d, 1 J CF =187H Z *), 109.6, 98.1, 96.9, 90.5 (* indicates long-range coupling with fluorine atoms, resulting in low accuracy). UV / Vis / NIR[(CH2Cl2):λ max (nm)(ε×10 5 mol -1 dm 3 cm -1 )]:387(0.61),600(0.48),762(0.067).HRMS:m / z;[M+H] + :calcd for C 70 H 18 F 30 N7:1526.1145; Found:1526.1117.

[0049] S4. Intermediate I-2 (25.8 mg, 16.9 μmol) was added to a 100 mL round-bottom flask, and then dissolved in dichloromethane (30 mL). After stirring at room temperature for 10 minutes, DDQ (7.67 mg, 33.8 μmol) was dissolved in dichloromethane (10 mL) and slowly added dropwise to the reaction system. The color of the solution rapidly changed from blue-purple to green. After stirring at room temperature for 1–2 hours, the reaction was quenched with water, washed with brine, and extracted with dichloromethane (4 × 10 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Column chromatography was performed using petroleum ether / dichloromethane = 4 / 1 (v / v) as the eluent to obtain a green solid compound I (21.4 mg, 83%). The 1H NMR, 1C NMR, mass spectrometry, and absorption spectra of compound I are as follows: 1 HNMR (600MHz, CDCl3, ppm) δ: 15.79 (s, 1H), 8.31 (d, J = 3.5Hz, 1H), 8.08 (s, 1H), 8.00 (d, J = 3.5Hz, 1H), 7.82 (m, 3H), 7.11 (d, J = 1.6 Hz,1H),6.41(d,J=4.1Hz,1H),6.03(d,J=3.4Hz,1H),5.97(s,1H),5.74(s,1H),5.29(s,1H),3.96(d,J=4.7Hz,1H),2.26(s,1H). 13C NMR (151MHz, Acetone-d6, ppm) δ: 180.0, 171.9, 167.1, 160.5, 155.5, 153.9, 152.9, 152.3, 150.9, 150.7, 149.8, 147.8 (d, 1 J CF =247H Z *), 147.5(d, 1 J CF =235H Z *), 146.5(d, 1 J CF =245H Z *), 146.2, 145.2, 142.7 (d, 1 J CF =254H Z *),142.3,142.2(d, 1 J CF =256H Z *), 139.0(d, 1 J CF =250H Z *),135.8,134.8,134.5,132.8,132.2,132.1,131.8,131.7,130.7,126.1,126.0,125.4,125.2,125.0,121.6,120.0,119.1,114.3(d, 1 J CF =203H Z *),111.4(d, 1 J CF =302H Z *), 109.0, 106.3, 101.2, 100.1, 99.7.

[0050] S5. Compound I (25.0 mg, 16.4 μmol) and copper chloride dihydrate (4.16 mg, 24.6 μmol) were added to a 50 mL round-bottom flask, and then 10 mL of dichloromethane was added to dissolve them. The mixture was stirred at room temperature for 15–30 minutes. The residual solid was removed by neutral alumina column chromatography. After removing the solvent under vacuum, the mixture was separated by column chromatography using petroleum ether / dichloromethane = 4 / 1 (v / v) as the eluent to obtain a dark olive-colored solid, compound II (21.3 mg, 82%). The 1H NMR, 1C NMR, mass spectrometry, and absorption spectra of compound II are as follows: 1HNMR(400MHz,CDCl3,ppm)δ:12.60(s,1H),9.85(s,1H),9.02(d,J=4.8Hz,1H),8.72(d,J=4.7Hz,1H),8.33(t,J=4.0Hz,2H),8.27(d,J=4.7Hz,1H),8.23(d,J=4.7Hz,1H),7.21–7.12(m,1H),6.87(d,J=5.5Hz,1H),6.41(d,J=4.7Hz,1H),6.34(d,J=4.6Hz,1H),5.12–4.97(m,1H),3.83(dd,J=3.7,2.4Hz,1H). 13 C NMR(151MHz,CDCl3,ppm)δ:167.3,155.3,153.9,153.4,152.8,151.3,150.9,150.2,148.6,147.4,146.1(d, 1 J CF =250H Z *),145.7(d, 1 J CF =253H Z *),144.9(d, 1 J CF =250H Z *),143.0,142.2(d, 1 J CF =261H Z *),141.6(d, 1 J CF =256H Z *),137.9(d, 1 J CF =247H Z *),137.4(d, 1 J CF =257H Z *),136.3,135.0,134.3,133.1,129.5,129.2,129.0,128.7,127.4,126.1,118.5,114.7,110.9(d, 1 J CF =289H Z *),113.9(d, 1 J CF =230H Z *),110.3,106.4,105.6,105.3,98.9,95.6,79.6,54.8.

[0051] Furthermore, the UV-Vis-NIR absorption spectra of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin I, its intermediate I-2, and complex II were obtained, revealing the color of the compounds in dichloromethane solution. Intermediate I-2 has a symmetrical structure containing two interlocked conjugated N-dislocated carbides, exhibiting sharp Soret-like absorption peaks at 387 and 600 nm, and a weak Q-like absorption peak near 762 nm, with the absorption band edge extending to approximately 1114 nm, consistent with its weak aromatic nature. Compared to I-2, compound I exhibits strong Soret-like absorption at 392 and 638 nm. The peaks show redshifted Q-like bands at 962 and 1379 nm with long band edges extending to about 1572 nm, consistent with its enhanced 18π aromaticity and 16π anti-aromaticity N-dislocation carbolic ring intercalation structure. In the structure of complex II, the carbolic ring of the trivalent copper complex still has aromaticity, and its absorption spectrum shows split Soret-like bands at 390 and 444 nm, as well as broad shoulder peaks in the 500–700 nm range. It exhibits a Q-like band with enhanced molar extinction coefficient at 746 nm, which is caused by the breaking of the conjugation of the N-dislocation carbolic ring on the other side after coordination with the trivalent copper ion.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An interlocked conjugated aromatic-antiaromatic bicyclic porphyrin, characterized in that: The structural formula of the interlocked conjugated aromatic-antiaromatic bicyclic porphyrin compound I is: 。 2. The interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to claim 1, characterized in that: The interlocked and conjugated aromatic-antiaromatic bicyclic porphyrin compound I was further used to prepare 18π aromatic bicyclic porphyrin monocopper complex II, the structural formula of which is: 。 3. A method for preparing an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to any one of claims 1-2, characterized in that: This preparation method includes the following steps: S1. Preparation of linear heptapyrrolidine I-1: At room temperature, the tetrapyrrole monoacylated raw material is reduced with sodium borohydride in a mixed solution of tetrahydrofuran or methanol. After the reaction is completed, water is added to quench the reaction. The mixture is then extracted, washed, dried, and the solvent is evaporated to obtain tetrapyrrole monool. No purification is required. S2. In an inert gas environment, the tetrapyrrolidine monool and tripyrrolidine raw materials obtained in step S1 are dissolved in dichloromethane, followed by condensation with trifluoroacetic acid. After the reaction is complete, triethylamine is added to quench the reaction, the solvent is directly evaporated, and the mixture is purified to obtain intermediate compound I-1. The structural formula of intermediate compound I-1 is as follows: S3. At room temperature, I-1 was dissolved in DCM, DDQ was added for oxidation, and the mixture was heated under reflux for 72 hours. Then, the mixture was extracted, washed, dried, and purified sequentially to obtain intermediate I-2, a blue-purple solid. DDQ was 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. The structural formula of intermediate I-2 is as follows: S4. At room temperature, intermediate I-2 was dissolved in DCM, DDQ was added for oxidation, and then the mixture was extracted, washed, dried and purified to obtain the target compound I as a dark green solid. S5. At room temperature, compound I was dissolved in DCM, copper chloride dihydrate was added, and then extracted, washed, dried and purified sequentially to obtain a dark olive-colored solid compound II.

4. The method for preparing an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to claim 3, characterized in that: In step S2, the molar ratio of the intermediate tetrapyrrolidine monool, tripyrrolidine, and trifluoroacetic acid is 1:2.5~3:0.3~0.5, and the reaction time is 1~2 hours.

5. The method for preparing an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to claim 3, characterized in that: In step S3, the molar mass ratio of intermediate I-1 to DDQ is 1:6~7.

6. The method for preparing an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to claim 3, characterized in that: In step S4, the molar mass ratio of intermediate I-2 and DDQ is 1:1~3, and the reaction time is 1~2 hours.

7. The method for preparing an interlocked conjugated aromatic-antiaromatic bicyclic porphyrin according to claim 3, characterized in that: In step S5, the molar mass ratio of compound I to copper chloride dihydrate is 1:1~2, and the reaction time is 15~30 minutes.

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