A macroconjugated molecular material DHRP containing five or seven ring systems and its preparation and application

Abstract

The present invention discloses a novel large conjugated molecule DHRP containing five or seven ring systems, and a preparation method and application thereof. The present invention successfully realizes the synthesis of the conjugated molecule DHRP containing five or seven ring systems through two steps of C-H bond activation reaction and Scholl reaction. Its structural formula is shown in Formula I. This step has a high yield and is simple to operate. The conjugated molecule DHRP has a novel structure, good stability, and good solubility in commonly used organic solvents. The DHRP molecule has a narrow absorption spectrum half-peak width and a certain solution fluorescence emission, and has potential applications in the fields of nonlinear optics.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis and material chemistry, and specifically relates to a macro-conjugated molecular material DHRP containing five or seven ring systems and the preparation and application thereof. Background Art

[0002] Large conjugated polycyclic aromatic hydrocarbons are an important class of organic optoelectronic materials. Introducing non-benzene-type ring systems (such as four-membered rings, five-membered rings, seven-membered rings and eight-membered rings) into large conjugated polycyclic hydrocarbons can bring about electronic configurations and structural characteristics that are different from those of benzene-type compounds. Therefore, research based on non-benzene-type polycyclic aromatic hydrocarbons has received increasing attention in recent years. Introducing five-membered rings into conjugated hydrocarbons can bring special properties to the compounds: 1) It is easy to obtain electrons to form stable aromatic cyclopentadienyl anions; 2) It has an asymmetric electronic configuration; 3) It can form bowl-shaped conjugated compounds with positive curvature. Since the discovery of C60, research on conjugated compounds containing five-membered rings has been extensive. Compared with five-membered rings, there are fewer studies on conjugated compounds containing seven-membered rings due to the difficulty of synthesis. Summary of the invention

[0003] The purpose of the present invention is to provide a novel macroconjugated molecule DHRP containing five or seven ring systems and its preparation method and application. The present invention designs and develops a novel macroconjugated molecule DHPR containing five or seven ring systems, completes its synthesis through a simple two-step reaction of direct CH bond arylation reaction and Scholl reaction, and tests the basic photophysical properties of these molecular materials.

[0004] The macroconjugated molecular compound DHRP containing five or seven ring systems provided by the present invention has a structural formula as shown in Formula I:

[0005]

[0006] In Formula I, R 1 and R 2 are independently selected from H, C 1 -C 50 A straight chain or branched alkyl group (specifically C 1 -C 10 Straight or branched alkyl, C 1 -C 6 straight-chain or branched alkyl, methyl, tert-butyl or hexyl), C 1 -C 50 The alkoxy group (specifically C 1 -C 10 Alkoxy, C 1 -C 6 alkoxy, methoxy, tert-butoxy and hexyloxy).

[0007] The large conjugated molecular compound DHRP containing five or seven ring systems shown in the above formula I is Figure 1 The reaction scheme shown is prepared by a method comprising the following steps:

[0008] 1) In the presence of a catalyst and an oxidant, DHR and biphenyl boronic anhydride shown in Formula 2 undergo CH bond arylation reaction to obtain an intermediate shown in Formula 3;

[0009] 2) subjecting the intermediate of formula 3, Lewis acid and protonic acid to a Scholl reaction in an organic solvent to obtain a large conjugated molecular compound DHRP containing five or seven ring systems as shown in formula I;

[0010]

[0011] In the above formula 2 and formula 3, R 1 and R 2 are independently selected from H, C 1 -C 50 A straight chain or branched alkyl group (specifically C 1 -C 10 Straight or branched alkyl, C 1 -C 6 straight-chain or branched alkyl, methyl, tert-butyl or hexyl), C 1 -C 50 The alkoxy group (specifically C 1 -C 10 Alkoxy, C 1 -C 6 alkoxy, methoxy, tert-butoxy and hexyloxy);

[0012] In step 1) of the above method, the catalyst is a palladium catalyst, which can be specifically selected from at least one of tetrakistriphenylphosphine palladium, palladium chloride, palladium acetate, 1,4-bis(diphenylphosphinobutane)palladium dichloride, bis(di-tert-butylphenylphosphine)palladium dichloride, bis(dibenzylideneacetone)palladium, and bis(triphenylphosphine)palladium dichloride, and specifically can be palladium acetate;

[0013] The oxidant is selected from at least one of tetrachlorobenzoquinone, o-tetrachlorobenzoquinone, 2,3-dichloro-5,6-dicyanobenzoquinone, potassium persulfate, potassium sodium persulfate, copper chloride, and phenanthrenequinone, and specifically may be o-tetrachlorobenzoquinone;

[0014] The molar ratio of DHR, biphenyl boronic anhydride shown in Formula 2, the catalyst and the oxidant may be 1:1-5:0.1-0.2:1-3, specifically 1:1.34:0.1:2.0;

[0015] The reaction temperature of the CH bond arylation reaction may be 30 to 100° C., specifically 60 to 100° C. or 80° C., and the reaction time may be 2 to 36 hours, specifically 5 to 10 hours or 8 hours;

[0016] The organic solvent may be selected from at least one of o-dichlorobenzene, o-xylene, chlorobenzene, tetrahydrofuran, toluene, cyclohexane, 1,4-dioxane, and ethylene dichloride;

[0017] After the CH bond arylation reaction is completed, the following operation is further included: removing the solvent from the system after the CH bond arylation reaction by a rotary evaporator, and separating and purifying the solid by a column chromatography method to obtain an intermediate shown in Formula 3.

[0018] In step 2) of the above method, the inert gas may specifically be nitrogen;

[0019] The Lewis acid can be selected from at least one of ferric chloride, 2,3-dichloro-5,6-dicyano-p-benzoquinone, molybdenum pentachloride, and aluminum chloride, and specifically can be 2,3-dichloro-5,6-dicyano-p-benzoquinone;

[0020] The protonic acid may be selected from at least one of trifluoromethanesulfonic acid, trifluoroacetic acid, hydrochloric acid and sulfuric acid, and may specifically be trifluoromethanesulfonic acid;

[0021] The molar ratio of the intermediate, Lewis acid and protonic acid shown in Formula 3 may be 1:2-12:1-300, specifically 1:4-8:80-150 or 1:6:100;

[0022] The reaction temperature of the Scholl reaction can be -30-100°C, specifically -10-10°C or 0°C, and the reaction time can be 0-8h, specifically 5min-30min, 15min-1h or 15min;

[0023] The organic solvent may be selected from at least one of dichloromethane, chloroform, toluene, chlorobenzene, tetrahydrofuran, cyclohexane, 1,4-dioxane, o-dichlorobenzene and o-xylene;

[0024] The Scholl reaction further includes the following operations: after adding hydrazine hydrate to quench the reaction, the system is filtered through diatomaceous earth and silica gel, washed with dichloromethane, the filtrate is subjected to a rotary evaporator to remove the solvent, and the solid is separated and purified by column chromatography to obtain a novel large conjugated molecular compound DHRP containing five or seven ring systems as shown in formula I.

[0025] The intermediate represented by formula 3 prepared by the above method also belongs to the protection scope of the present invention.

[0026] The present invention also provides the use of the novel macroconjugated molecular compound containing five or seven ring systems as shown in the above formula I as an optoelectronic material (specifically a nonlinear optical material) or in the preparation of an optoelectronic material (specifically a nonlinear optical material).

[0027] The present invention has the following advantages:

[0028] The present invention designs and synthesizes the biphenyl-substituted DHR shown in Formula 3 and the novel macroconjugated molecule compound DHRP containing five or seven ring systems shown in Formula 1. The synthesis of the novel macroconjugated molecule containing five or seven ring systems is successfully achieved through two-step reactions of CH bond activation reaction and Scholl reaction. The reaction yield involved in the synthesis is high and the operation is simple. The designed and synthesized novel macroconjugated molecule containing five or seven ring systems has a novel structure, good stability and good solubility in commonly used organic solvents. The novel macroconjugated molecule containing five or seven ring systems shown in Formula I provided by the present invention has a narrow half-peak width and a certain solution fluorescence emission, and has potential applications in the fields of nonlinear optics. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a reaction flow chart for preparing the macro-conjugated molecular compound DHRP containing five or seven ring systems as shown in formula I.

[0030] Figure 2 This is the reaction equation for preparing the large conjugated molecule DHRP containing five or seven ring systems shown in formula I using DHR as a raw material in the present invention.

[0031] Figure 3 The UV-visible absorption spectrum and emission spectrum of the compound DHRP prepared in Example 1 of the present invention in a dichloromethane solution.

[0032] Figure 4 The cyclic voltammetry curve of the compound DHRP prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0034] The experimental methods in the following examples, unless otherwise specified, are conventional methods, and are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources. Among them, the raw material DHR is synthesized according to the reference method (Angew. Chem., Int. Ed. 2020, 59, 3529-3533.).

[0035] The present invention provides a novel macroconjugated molecular compound DHRP containing five or seven ring systems, and characterizes its basic photoelectric properties such as absorption, emission, and electrochemistry. Its structural formula is shown in Formula I:

[0036]

[0037] In Formula I, R 1 and R 2 are independently selected from H, C 1 -C 50 A straight chain or branched alkyl group (specifically C 1 -C 10 Straight or branched alkyl, C 1 -C 6 straight-chain or branched alkyl, methyl, tert-butyl or hexyl), C 1 -C 50 The alkoxy group (specifically C 1 -C 10 Alkoxy, C 1 -C 6 alkoxy, methoxy, tert-butoxy and hexyloxy).

[0038] Example 1, Synthesis of the compound DHRP described in Formula I:

[0039] Chemical reaction flow chart Figure 2 As shown, the specific reaction step conditions are as follows:

[0040] Add DHR (50 mg, 0.13 mmol, 1.0 eq.), compound 2 (157 mg, 0.18 mmol, 1.34 eq.), palladium acetate (3.0 mg, 0.013 mmol, 0.10 eq.), o-tetrachlorobenzoquinone (65.7 mg, 0.27 mmol, 2.0 eq.) to a 50 ml reaction tube with a stirrer. Then inject 20 ml of 1,2-dichloroethane into the system. Place the system in an oil bath, heat to 80 ° C, and reflux for 8 hours. After cooling to room temperature, spin dry the system. Separate by column chromatography, gradient elution, the eluent polarity increases from petroleum ether: dichloromethane = 15:1, to petroleum ether: dichloromethane = 10:1, and finally to petroleum ether: dichloromethane = 5:1. 238.6 mg of a blue solid compound was isolated with a yield of 32.0%. The characterization data of intermediate compound 2 are as follows: HRMS (MALDI-TOF): calculated value is C70H62 ([M]+): 902.4846; experimental observation value: 902.4840.

[0041] Add compound 2 (83 mg, 0.09 mmol, 1.0 eq.) and 2,3-dichloro-5,6-dicyanobenzoquinone (126 mg, 0.55 mmol, 6.0 eq.) to a 50 ml flask with a stirrer, and replace the system with nitrogen using the Shrek technique. Then inject 15 ml of dichloromethane, place the system at 0 ° C, slowly inject 0.8 ml of trifluoromethanesulfonic acid into the system, and stir at 0 ° C for 15 min. After the reaction of the raw materials is complete as monitored by TLC, add about 3 ml of hydrazine hydrate to quench the reaction. Filter the system with diatomaceous earth and silica gel, and wash the solid with dichloromethane until the color becomes lighter. The filtrate is spin-dried, separated by column chromatography, and gradient eluted. The polarity of the eluent was increased from petroleum ether: dichloromethane = 10:1 to petroleum ether: dichloromethane = 5:1 and finally to petroleum ether: dichloromethane = 3:1. 39.6 mg of green solid compound 3 (DHRP) was isolated with a yield of 48.2%.

[0042] The structural confirmation data are as follows:

[0043] 1 H NMR (700MHz, d8-THF): δppm=9.58(s,2H),9.18(s,2H),8.88(d,J=8.54,2H),8.74(d,J=7.91,2H),8.70(d, J=8.26,2H),8.19(d,J=8.19,2H),7.93(d,J=8.33,2H),7.82(t,J=7.49,2H),2.06(s,18H),1.61(s,18H);

[0044] 13C NMR (175MHz, CD 2 Cl 2 ): δppm=148.1,147.6,140.2,139.2,136.7,136.0,134.9,134.5,134.3,134.1,132.4,132.4,132.02,131.3,131 .2,131.1,128.8,128.3,126.8,125.9,125.3,125.2,123.7,123.6,123.3,123.3,120.6,36.3,35.3,31.9,31.6;

[0045] HRMS (MALDI-TOF): calculated value is C70H54 (M + ):894.4224; experimental observation value: 894.4220.

[0046] It can be seen from the above that the product structure is correct, and it is the compound DHRP shown in formula I.

[0047] Example 2, UV-visible absorption spectrum and emission spectrum of compound DHRP in solution:

[0048] The compound DHRP prepared in Example 1 of the present invention was dissolved in dichloromethane solvent (concentration of 10 -5 mol / L), the absorption spectrum of DHRP in solution was measured as follows Figure 3 As shown (solid line). Figure 3 It can be seen that the maximum absorption wavelength of the compound DHRP is at 690nm, and there is also a strong absorption peak at 632nm. The quantum yield of the solution of the compound DHRP is 4.0%, and its emission spectrum is as follows Figure 3 As shown (dashed line), its maximum emission wavelength is 697 nm, with a weak emission peak at 768 nm.

[0049] Example 3: Electrochemical properties and frontier orbital energy levels (LUMO and HOMO) of DHRP were measured using electrochemical cyclic voltammetry:

[0050] The electrochemical properties of the compound DHRP in Example 1 of the present invention were tested using an electrochemical workstation, with ferrocene as the standard and a dichloromethane solution of tetrabutylammonium hexafluorophosphate (concentration of 0.1 M) as the electrolyte. A standard three-electrode system was used for the test, with a glassy carbon electrode as the working electrode, a platinum wire as the counter electrode, and an Ag / Ag + As the reference electrode. The cyclic voltammetry curve is as follows Figure 4 As shown, from Figure 4It can be seen that the compound DHRP has two reversible reduction peaks, with reduction peak potentials at -1.57eV and -1.98eV (vs Fc + / Fc). The compound DHRP has two strong oxidation peaks, with the oxidation peak potentials at 0.46eV and 0.84eV, respectively. In addition, there is a weaker oxidation peak at around 0.26eV. The calculated LUMO energy level is -3.34eV, and the HOMO energy level is -5.10eV.

[0051] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wider range under equivalent parameters and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principles of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including changes that depart from the disclosed scope in the application and are made with conventional techniques known in the art.

Claims

1. A large conjugated molecule DHRP containing five or seven ring systems, the structural formula of which is shown in Formula I: In Formula I, R 1 is tert-butyl, R 2 For H.

2. A method for preparing the large conjugated molecule DHRP according to claim 1, comprising the following steps: 1) DHR and biphenyl boronic anhydride shown in Formula 2 are subjected to a CH bond arylation reaction in the presence of a catalyst and an oxidant to obtain an intermediate molecule shown in Formula 3; 2) the intermediate molecule shown in Formula 3 is subjected to a Scholl reaction under the action of a Lewis acid and a protonic acid to obtain a large conjugated molecule DHRP containing five or seven ring systems shown in Formula I; In formula 2 and formula 3, R 1 and R 2 The same definition as R in claim 1 1 and R 2 Definition of .

3. The method according to claim 2, Features: In step 1), the catalyst is a palladium catalyst, selected from at least one of tetrakistriphenylphosphine palladium, palladium chloride, palladium acetate, 1,4-bis(diphenylphosphinobutane)palladium dichloride, bis(di-tert-butylphenylphosphine)palladium dichloride, bis(dibenzylideneacetone)palladium, and bis(triphenylphosphine)palladium dichloride; The oxidant is selected from at least one of tetrachlorobenzoquinone, o-tetrachlorobenzoquinone, 2,3-dichloro-5,6-dicyanobenzoquinone, potassium persulfate, potassium sodium persulfate, cupric chloride, and phenanthrenequinone; The molar ratios of DHR, biphenyl borate ester shown in formula 2, the catalyst and the oxidant are 1:1-5:0.1-0.2:1-3 respectively.

4. The method according to claim 2, Features: The reaction temperature of the CH bond arylation reaction is 30 to 100° C., and the reaction time is 2 to 36 hours.

5. The method according to claim 2, Features: In step 2), the Lewis acid is selected from at least one of ferric chloride, 2,3-dichloro-5,6-dicyanobenzoquinone, molybdenum pentachloride, and aluminum chloride; The protonic acid is selected from at least one of trifluoromethanesulfonic acid, trifluoroacetic acid, hydrochloric acid and sulfuric acid; The molar ratios of the intermediate, Lewis acid and protonic acid shown in formula 3 are 1:2-12:1-300 respectively.

6. The method according to claim 2, Features: The reaction temperature of the Scholl reaction is -30-100°C, and the reaction time is 0-8h.

7. Use of the macroconjugated molecule DHRP containing five or seven ring systems as claimed in claim 1 as a photoelectric material or in the preparation of a photoelectric material.

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