CN115466403A - Two kinds of butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes and their preparation methods and uses - Google Patents

Abstract

The present invention relates to two kinds of butoxybenzodithiophene derivatives mercury amalgamated and cadmium homopolymer complexes BDTT‑VBT‑Hg and BDTT‑VBT‑Cd shown in formula 1 and their preparation methods and their use as dye-sensitized solar cells The use of dye sensitizers in the middle, the polymer complex dye sensitizer is 4,5-dibutoxy-2,7-divinyl benzo[2,1-b:3,4-b'] The metal complex formed by dithiophene as the main ligand and metal coordination is used as the auxiliary electron acceptor A', and benzodithiophene dithiophene (BDTT) is used as the electron donor D to synthesize D‑A'‑π by Heck reaction ‑A-type homopolymeric complexes, experiments based on this type of homopolymeric complex dye sensitizers have shown good results in photovoltaic performance tests of dye-sensitized solar cells: the photoelectric conversion efficiencies reached 12.89%, 11.23%, respectively, Its thermal decomposition temperature is above 260°C, and its thermal stability is good, which will have certain prospects in the development and application of dye-sensitized solar cells;

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Description

Two Butoxybenzodithiophene Derivatives Mercury and Cadmium Homopolymeric Complexes and Their Preparation Method and use

technical field

The invention relates to two kinds of butoxybenzodithiophene derivatives mercury amalgamation and cadmium homopolymerization complexes BDTT-VBT-Hg, BDTT-VBT-Cd and their preparation methods and their application as dye sensitizers. The development and application of photosensitive materials in dye-sensitized solar cells (DSSCs) belongs to the field of photoelectric materials in new materials.

Background technique

Compared with traditional silicon solar cells, dye-sensitized solar cells (DSSCs) have low cost of raw materials and are not sensitive to the angle of light during operation. Part of it has been researched and developed by many scientists; in order to continuously improve the photovoltaic performance of dye sensitizers, from its initial D-A structure to D-π-A structure, it has developed to the popular D-A'-π- A structure; for the D-A'-π-A structure, it introduces an auxiliary electron acceptor A' on the basis of the D-π-A structure to increase the ability of the electron acceptor to pull electrons and reduce electron recombination, making DSSCs A new breakthrough has been made in the photoelectric conversion efficiency, and at the same time, other photoelectric properties of DSSCs, such as thermal stability, have been effectively improved. Therefore, the research on the auxiliary electron acceptor A' has become a research hotspot in the field of DSSCs. The research of the present invention is based on the Metal complexes with strong electron-absorbing ability and the ability to adjust the electron-absorbing ability by adjusting the strength of the coordination bond were used as auxiliary electron acceptors A'. Two kinds of butoxybenzodithiophene derivatives amalgamated with mercury and cadmium were designed and prepared Homopolymeric complexes BDTT-VBT-Hg, BDTT-VBT-Cd, test data show good photovoltaic performance.

Contents of the invention

The object of the present invention is to provide and prepare two kinds of butoxybenzodithiophene derivatives mercury, cadmium homopolymerization complexes BDTT-VBT-Hg, BDTT-VBT-Cd, to be used as D in dye-sensitized solar cells -A'-π-A dye sensitizer, the polymer complex uses benzodithiophene derivative BDTT as electron donor D, and 4,5-dibutoxy-2,7-divinylbenzo The complex formed by [2,1-b: 3,4-b']dithiophene and metal coordination is the coreacceptor A', with 2-cyano-3-(8-hydroxyquinolin-5-yl) Acrylic acid acts as a π bridge and an anchoring group, and the electron donor D and the electron absorber part (-A'-π-A) are polymerized through a Heck coupling reaction to form the above two metal complex dye sensitizers. The compound has good photoelectric conversion efficiency and thermal stability. Based on the above two complexes as dye sensitizers, the photoelectric conversion efficiency of the dye-sensitized solar cell is 12.89% and 11.23%, respectively. The general structural formula is as follows:

The preparation method of two kinds of butoxybenzodithiophene derivatives mercury and cadmium homopolymerization complex BDTT-VBT-Hg, BDTT-VBT-Cd:

(1) Preparation of 1,2-dithiophene-1,2-dione:

After adding thiophene-3-carbaldehyde and K ₂ CO ₃ in a molar ratio of 1.0:1.2 to 1.0:1.8 into the single-necked flask, then DMSO and 3-benzyl-5-(2-hydroxyethyl)-4- Add methylthiazolium bromide, then heat and reflux for 34-38 hours under the atmosphere of carbon dioxide, cool to room temperature after the reaction is completed, then add water, and extract with ether three times, then add anhydrous magnesium sulfate to dry, filter and spin dry A light yellow liquid was obtained, and the obtained crude product was separated by a column using a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:10 to 1:15 as an eluent to obtain a golden yellow needle-like solid 1,2-dithiophene -1,2-dione;

(2) Preparation of benzo[1,2-b:6,5-b']dithiophene-4,5-dione:

Add dichloromethane and 1,2-dithiophene-1,2-dione into a one-necked flask and stir to dissolve, then slowly add FeCl ₃ , and react at 45°C for 22-26 hours. After the reaction is completed, let it stand for 1-2 hours 2h, add deionized water, extract three times with dichloromethane, collect the organic phase and dry with anhydrous magnesium sulfate, filter and spin dry to obtain a black flocculent solid, the obtained crude product is acetic acid with a volume ratio of 1:10 to 1:15 The mixed solution of ethyl ester and petroleum ether was used as eluent for column separation to obtain black needle-like solid benzo[1,2-b:6,5-b']dithiophene-4,5-dione;

(3) Preparation of 2,7-dibromobenzo[1,2-b:6,5-b']dithiophene-4,5-dione:

Add benzo[1,2-b:6,5-b']dithiophene-4,5-dione and NBS at a molar ratio of 1.0:1.8 to 1.0:2.4 into a single-necked flask, then add DMF , followed by reaction at 70°C for 2 2 to 26 hours, cooled to room temperature after the reaction was completed, poured into water and allowed to stand for 30 to 60 minutes, then dried with suction to obtain light blue solid 2,7-dibromobenzo[1,2 -b: 6,5-b']dithiophene-4,5-dione;

(4) Preparation of 2,7-divinylbenzo[2,1-b:3,4-b']dithiophene:

Add 2,7-dibromobenzo[1,2-b:6,5-b']dithiophene-4,5-dione and vinyl in a molar ratio of 1.0:1.5 to 1.0:2.5 Potassium trifluoroborate, then cesium carbonate, 2-dicyclohexylphosphine-2',6'-diisopropoxy-1,1'-biphenyl, palladium chloride, and then slowly drop tetrahydrofuran solution, followed by Under the protection of nitrogen, heat and reflux for 22 to 26 hours. After the reaction is completed, cool to room temperature, distill off excess solvent under reduced pressure, pour into water and extract three times with ethyl acetate, collect the organic phase and dry it with anhydrous magnesium sulfate, filter and spin dry. The resulting crude product was separated by column using a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:10 to 1:14 as an eluent to obtain a black solid 2,7-divinylbenzo[2,1- b: 3,4-b']dithiophene;

(5) Preparation of 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene:

Add 2,7-divinylbenzo[2,1-b:3,4-b']dithiophene and n-bromobutane in a molar ratio of 1.0:0.8 to 1.0:1.2 into a three-necked flask, and then add four Butylammonium bromide, sodium hydrosulfite and tetrahydrofuran solution, under the protection of nitrogen, slowly add KOH solution dropwise through a constant pressure dropping funnel, after the drop is completed, react at 80°C for 46-50h, and cool to room temperature after the reaction is completed , extracted three times with ethyl acetate, collected the organic phase and dried with anhydrous magnesium sulfate, filtered and spin-dried to obtain a light yellow liquid crude product, the obtained crude product was mixed with ethyl acetate and petroleum ether with a volume ratio of 1:36 to 1:44 The mixed solution was used as eluent for column separation to obtain yellow liquid 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene;

(6) Preparation of 5-formyl-8-hydroxyquinoline:

Add 8-hydroxyquinoline and absolute ethanol to the three-necked flask, add sodium hydroxide solution through a constant pressure separatory funnel under stirring, heat to 80°C to reflux after complete dissolution, and then slowly add through a constant pressure separatory funnel Chloroform, the molar ratio of 8-hydroxyquinoline to chloroform is 1.0:2.0～1.0:2.4, react for 22～26h, after the reaction is completed, remove ethanol and chloroform by distillation under reduced pressure, then pour distilled water, neutralize to pH with dilute hydrochloric acid It was 7.0, and the brown solid was obtained by suction filtration, and the brown block was obtained after vacuum drying, which was ground to powder and continued to dry, then washed with petroleum ether, and the washing liquid was cooled, and the remaining solid after filtering the supernatant was washed with absolute ethanol Recrystallized twice, dried to obtain orange pink filamentous crystal 5-formyl-8-hydroxyquinoline;

(7) Preparation of 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid:

Add 5-formyl-8-hydroxyquinoline and cyanoacetic acid with a molar ratio of 1.0:1.2 to 1.0:1.8 in a three-necked flask, then add acetic acid and acetonitrile, stir until dissolved, add piperidine after dissolution, and then React at 90°C for 34 to 38 hours. After the reaction is completed, spin the solvent and dry it. Grind the solid into a powder and wash it three times with chloroform. After drying the solid, recrystallize it twice with ethanol to obtain an orange powder 2- Cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid;

(8) Preparation of metal complex VBT-Hg:

Add 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b'] di Thiophene and 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid, then _THF was added, followed by dissolution at 40 °C, and then HgCl was dissolved in anhydrous methanol and passed through a constant pressure funnel slowly Add dropwise, and react at 75°C for 22-26h. After the reaction is completed, cool to room temperature, put it in the refrigerator overnight, then filter, and then wash with water three times and absolute ethanol three times, and finally obtain a light yellow solid Hg complex VBT -Hg;

(9) Preparation of metal complex VBT-Cd:

The synthesis method of the complex VBT-Cd is the same as that of VBT-Hg, and the HgCl ₂ is replaced by Cd(CH ₃ COO) ₂ ·2H ₂ O, and finally the golden yellow solid complex VBT-Cd containing Cd is obtained;

(10) Preparation of polymeric complex BDTT-VBT-Hg:

Add the Hg-containing complex VBT-Hg and 2,6-dibromo-4,8-bis(5-(2-ethyloctyl)thiophene-2 at a molar ratio of 1.0:0.8 to 1.0:1.2 -yl) benzo[1,2-b:4,5-b']dithiophene (BDTT), then add zinc powder, triphenylphosphine, δ bis(triphenylphosphine) nickel dichloride, 2 , 2'-bipyridyl and DMF, according to the Heck polymerization reaction, under the protection of nitrogen, reflux for 46 ~ 50h, after the reaction, filter, then fully wash with absolute ethanol, dry to obtain a brown-green solid polymer complex BDTT-VBT -Hg;

(11) Preparation of polymeric complex BDTT-VBT-Cd:

The synthesis method of the polymer complex BDTT-VBT-Cd is the same as that of BDTT-VBT-Hg, and the Hg-containing complex VBT-Hg is replaced by the metal complex VBT-Cd, and finally the dark brown solid polymer complex BDTT- VBT-Cd;

The use of two butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd: used in dye-sensitized solar cells to absorb sunlight and generate and transport electrons dye sensitizers;

The main advantages of this invention are: (1) Invented two kinds of butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes, which are derived from benzodithiophene with strong electron donating ability (BDTT) as donor D, after coordination with 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene and metal The formed complex is used as co-acceptor A', and 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid coordinates with the metal to form a π bridge, acceptor A and anchoring group, and the Heck The complex synthesized by connecting the donor and the acceptor part of the complex -A'-π-A, the complex has good photoelectric conversion efficiency, and the photoelectric conversion efficiency is 12.89% and 11.23%, respectively. (2) Preparation method It is simple and the raw materials are easy to obtain; (3) it has good electrochemical performance, thermal performance and light stability, and the thermal decomposition temperature is above 260° C., which is beneficial to practical application.

Description of drawings

Figure 1 shows the proton nuclear magnetic resonance spectrum ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm) of the ligand 1,2-dithiophene-1,2-dione synthesized in the example of the present invention;

Fig. 2 Proton nuclear magnetic resonance spectrum ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm);

Figure 3 shows the proton nuclear magnetic resonance spectrum ( ¹ H- NMR) (400MHz, CDCl ₃ , ppm);

Fig. 4 Proton nuclear magnetic resonance spectrum ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm);

Figure 5 shows the hydrogen nuclear magnetic resonance spectrum of the ligand 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene synthesized in the embodiment of the present invention ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm);

Fig. 6 is the hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm) of the ligand 5-formyl-8-hydroxyquinoline synthesized in the embodiment of the present invention;

Figure 7 is the hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) (400MHz, CDCl ₃ , ppm) of the ligand 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid synthesized in the example of the present invention;

Figure 8 is the infrared spectrum (FT-IR) (KBr, cm ^-1 ) of the metal complexes VBT-Hg and VBT-Cd synthesized in the example of the present invention;

Figure 9 is the infrared spectrum (FT-IR) (KBr, cm ^-1 ) of the polymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd synthesized in the example of the present invention;

Figure 10 is the thermogravimetric analysis curve (TGA) (N ₂ , 20°C/min) of the polymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd synthesized in the example of the present invention;

Figure 11 is the current density-voltage (J-V) curve of the dye-sensitized solar cell in which the polymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd synthesized in the examples of the present invention are used as dye sensitizers;

Figure 12 is the external quantum efficiency (IPCE) curve of a dye-sensitized solar cell in which the polymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd synthesized in the examples of the present invention are used as dye sensitizers.

detailed description

The reaction synthesis routes of two kinds of butoxybenzodithiophene derivatives mercury amalgamation and cadmium homopolymer complexes BDTT-VBT-Hg and BDTT-VBT-Cd of the present invention are shown in formula 1:

Formula 1 two kinds of butoxybenzodithiophene derivatives amalgamated with mercury, the synthetic route of cadmium homopolymerization complex

Below in conjunction with specific embodiment the present invention will be further described

Example 1:

The molecular structural formulas of two butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes BDTT-VBT-Hg and BDTT-VBT-Cd are shown in Formula 2:

Formula 2 Molecular structural formula of two kinds of polymers

Preparation of the above two butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes BDTT-VBT-Hg, BDTT-VBT-Cd:

A. Preparation of 1,2-dithiophene-1,2-dione: 3.6g thiophene-3-carbaldehyde (30 mmol), 6.18g K ₂ CO ₃ (45 mmol), 16ml DMSO and 0.153g 3-benzyl Base-5-(2-hydroxyethyl)-4-methylthiazolium bromide was added to a 50ml single-necked flask, and the temperature was raised to 60°C in an atmosphere of carbon dioxide to react for 36h. After the reaction was completed, cool to room temperature, and add 100mL of water , extracted three times with 50 mL of anhydrous ether, collected the organic phase, added anhydrous magnesium sulfate to dry, filtered and spin-dried to obtain a light yellow liquid, and the resulting crude product was washed with ethyl acetate and petroleum ether at a volume ratio of 1:12. After column separation, 1.62 g of golden yellow needle-like solid was obtained with a yield of 73%, mp94.1-94.7°C; FT-IR (KBr, cm ^-1 ): 3440 cm ^-1 (-OH), 3110 cm ^-1 (=CH ), 1680cm ^-1 (C＝O), 1160cm ^-1 (CC), 1500cm ^-1 (C＝C), 1100cm ^-1 (CS), 700cm ^-1 (＝CH), H NMR spectrum ( ¹ H- NMR) see accompanying drawing 1, ¹ H-NMR (CDCl ₃ , ppm): 8.35-8.36 (d, 1H), 7.69-7.71 (d, 1H), 7.39-7.41 (q, 1H), ¹³ C-NMR ( CDCl ₃ , ppm): 186.81, 137.59, 137.50, 127.54, 126.96;

B. Preparation of benzo[1,2-b:6,5-b']dithiophene-4,5-dione: Mix 150 mL of dichloromethane and 2.22 g of 1,2-dithiophene-1,2-dione Add ketone (10mmol) into a 250mL single-necked flask and stir for 5min, then slowly add 8.1gFeCl ₃ (50mmol), react at 45°C for 24h, let stand for 1h after the reaction is complete, add 300ml of water, extract three times with dichloromethane, The collected organic phase was dried with anhydrous magnesium sulfate, filtered and spin-dried to obtain a black flocculent solid, and the obtained crude product was separated by column separation with ethyl acetate and petroleum ether at a volume ratio of 1:12 to obtain a black needle Solid 1.76g, yield 80%, mp289.1-289.6℃; FT-IR (KBr, cm ^-1 ): 3090cm ^-1 (=CH), 2930cm ^-1 , 2850cm ^-1 , 1390cm ^-1 , 1280cm ^{- 1} (-CH), 1660cm ^-1 (C=O), 1510cm ^-1 (C=C), 1100cm ^-1 (CS), 885cm ^-1 (CC), 727cm ^-1 (=CH), H NMR ( ¹ H-NMR) See Figure 2, ¹ H-NMR (CDCl ₃ , ppm): 7.50(d,1H,=CH), 7.20(d,1H,=CH), ¹³ C-NMR (CDCl ₃ , ppm): 174.62, 143.96, 135.11, 127.88, 125.66;

C. Preparation of 2,7-dibromobenzo[1,2-b:6,5-b']dithiophene-4,5-dione: 4.40g benzo[1,2-b:6, 5-b']dithiophene-4,5-dione (20mmol), 3.738g NBS (42mmol) and 100mL DMF were added to a 250mL single-necked flask, heated to 70°C for 24h, cooled to room temperature after the reaction was completed, poured In 400mL of water, let it stand for 30min, and then dried after suction filtration to obtain 2.85g of a light blue solid with a yield of 75.3%; mp204.3-204.9℃, FT-IR (KBr, cm ^-1 ): 3450cm ^-1 (-OH ),30110cm ^-1 (=CH),2930cm ^-1 ,2850cm ^-1 , 1410cm ^-1 ,1280cm ^-1 (-CH),1680cm ^-1 (C=O),1510cm ^-1 (C=C),1080 cm ^-1 (CS), 629cm ^-1 (C-Br), hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) see Figure 3, ¹ H-NMR (CDCl ₃ , ppm): 7.47(s,1H,=CH) , ¹³ C-NMR (CDCl ₃ , ppm): 172.57, 143.63, 135.37, 130.03, 114.65;

D. Preparation of 2,7-divinylbenzo[2,1-b:3,4-b']dithiophene: Add 0.378g 2,7-dibromobenzo[1, 2-b: 6,5-b']dithiophene-4,5-dione (1 mmol), 0.978 g cesium carbonate (3 mmol), 27.9 mg 2-dicyclohexylphosphine-2',6'-diiso Propoxy-1,1'-biphenyl (0.06mmol), 3.5mg of palladium chloride (0.02mmol), 0.281g of potassium vinyl trifluoroborate (2.1mmol), then slowly dropwise added 11ml of tetrahydrofuran solution (tetrahydrofuran: water =10:1), under the protection of nitrogen, the temperature was slowly raised to 85°C for 24 hours. After the reaction was completed, it was cooled to room temperature. After the solution was spin-dried, it was poured into water and extracted three times with ethyl acetate, and the organic phase was collected and washed with anhydrous sulfuric acid. Dried over magnesium, filtered and spin-dried, the crude product was separated by column with petroleum ether and ethyl acetate at a volume ratio of 12:1 to obtain 0.177g of black powder with a yield of 65%, mp179.5-181 ℃; Proton Nuclear Magnetic Resonance Spectrum ( ¹ H-NMR) see Figure 4, ¹ H-NMR (CDCl ₃ , ppm): 7.32(s,1H), 6.71-6.78(q,1H), 5.61-5.66(d, 1H), 5.33-5.36(d, 1H); ¹³ C-NMR (CDCl ₃ , ppm): 174.29, 143.45, 142.17, 135.56, 128.55, 125.36, 116.73; FT-IR (KBr, cm ^-1 ): 3430 cm ^-1 (-OH), 3090cm ^-1 (=CH), 2920cm ^-1 , 2850cm ^-1 (CH), 1650cm ^-1 (C=O), 1570cm ^-1 , 1500cm ^-1 (C=C);

E. Preparation of 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene: 1.08g 2,7-divinylbenzene And [2,1-b:3,4-b']dithiophene (4mmol), 0.58g n-bromobutane (4.2mmol), 0.87g tetrabutylammonium bromide (2.7mmol), 4.44g sodium bicarbonate ( 25.5mmol) into a 100mL three-necked flask, then added 30mL tetrahydrofuran solution (tetrahydrofuran: water = 3:2), and slowly added KOH solution (KOH2.3g, H ₂ O 10mL), after the dropwise addition was completed, the temperature was slowly raised to 80°C for 48 hours. After the reaction was completed, it was cooled to room temperature, extracted three times with 30mL ethyl acetate, and the organic phase was collected and dried with anhydrous magnesium sulfate. After filtration and spin-drying, a light yellow liquid was obtained. The product was separated by a column using petroleum ether and ethyl acetate at a volume ratio of 40:1 as eluents to obtain 0.84 g of a yellow liquid product with a yield of 54%. The hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR) is shown in Figure 5 , ¹ H-NMR(CDCl ₃ ,ppm):7.43(s,1H),4.10-4.13(t,2H),0.97-1.01(t,3H); ¹³ C-NMR(CDCl ₃ ,ppm):142.78, 134.15, 129.02, 124.66, 112.84, 74.13, 13.97, FT-IR (KBr, cm ^-1 ): 3420cm ^-1 (-OH), 2920cm ^-1 , 2850cm ^-1 (CH), 1640cm ^-1 (C＝C) , 1550cm ^-1 (C=C), 1460cm ^-1 (-CH ₂ ), 1380cm ^-1 (-CH ₃ ), 1270cm ^-1 (COC);

The preparation of F.5-formyl-8-hydroxyquinoline: add the 8-hydroxyquinoline of 20g (137.6mmol) successively in the three-neck flask of 500ml, then add the dehydrated alcohol of 80ml again and pass constant Slowly add sodium hydroxide solution (NaOH 40g, H ₂ O 40mL) with a mass ratio of 1:1 into the pressure separating funnel, heat the system to reflux at 80°C after the system is completely dissolved, and then slowly add 36g through the constant pressure separating funnel within 1h (304mmol) CHCl ₃ , after the dropwise addition, react for another 24h. After the reaction is complete, add 50ml of distilled water and remove ethanol and chloroform by distillation under reduced pressure. : water = 10: 1) to neutralize to pH 7, vacuum-dry after suction filtration to obtain brown blocky objects, grind to powdery solids and continue to dry, then wash with petroleum ether after drying, and cool the washing liquid overnight to precipitate Orange solid, after filtering the supernatant, the remaining solid was recrystallized twice with absolute alcohol, and the obtained solid was dried to obtain 3.0 g of orange-pink filamentous crystals, with a yield of 12.3%, mp171.8～172.9°C; FT- IR(KBr, cm ^-1 ): 3447cm ^-1 (-OH), 2920cm ^-1 (CH), 1690cm ^-1 (C=O), 1576cm ^-1 (C=C), 1510cm ^-1 (C=N) ; Proton nuclear magnetic resonance spectrum ( ¹ H-NMR) is shown in Figure 6, ¹ H-NMR (CDCl ₃ , ppm): 10.15(s,1H), 9.67(d,1H), 8,87(d,1H), 8.00(d,1H),7.67(q,1H),7.65(d,1H); ¹³ C-NMR(CDCl ₃ ,ppm):192.04,157.86,148.74,140.45,137.85,134.76,126.59,124.72,123.56, 109.02;

G. Preparation of 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid: 3.0g (17.3mmol) 5-formyl-8-hydroxyquinoline, 2.22 After g (26.0 mmol) cyanoacetic acid, add 9ml of acetic acid, then add 100ml of acetonitrile, stir until dissolved, slowly add 1ml of piperidine after dissolving, react the system at 90°C for 36h, after the reaction is complete, spin to dry the solvent Dry in a vacuum oven to obtain a yellow blocky crude product. Grind the crude product into a powder and wash the solid three times with chloroform. After the solid is dried, it is recrystallized twice with ethanol to obtain 2.0 g of an orange powder. The yield is 59.1%, mp200～201°C; hydrogen nuclear magnetic resonance ( ¹ H-NMR) is shown in Figure 7, ¹ H-NMR (DMSO-d ₆ , ppm): 8.96(s,1H), 8.87(d, 1H), 8.62(d,1H), 8.42(d,1H), 7.71(q,1H), 7.26(d,1H); the active hydrogens on the hydroxyl and carboxyl groups cannot be characterized in 1H NMR due to the formation of hydrogen bonds However, it can be combined with FT-IR and ¹³ C-NMR to prove that the target product was successfully synthesized. The results are as follows: FT-IR (KBr, cm ^-1 ): 3180cm ^-1 (-OH), 2235cm ^-1 (C≡N) , 1896cm ^-1 (C=O), 1662cm ^-1 (C=O), 1613cm ^-1 (C=C), 1566cm ^-1 (C=N); ¹³ C-NMR (CDCl ₃ , ppm): 164.17, 159.12, 150.04, 149.44, 138.68, 132.58, 131.15, 128.71, 123.93, 118.86, 117.26, 112.16, 102.93;

H. Preparation of Hg-containing complex VBT-Hg: 0.193g 4,5-dibutoxy-2,7-divinylbenzo[2,1-b:3,4-b']dithiophene ( 0.5mmol), 0.12g 2-cyano-3-(8-hydroxyquinolin-5-yl)acrylic acid (0.55mmol), 25mL THF were added to a 50mL single-necked bottle, and it was heated to 40°C to dissolve, and then Dissolve 0.149g HgCl ₂ (0.55mmol) in 20mL of anhydrous methanol, and slowly add it dropwise through a constant pressure funnel, raise the temperature to 75°C for 24 hours, cool to room temperature after the reaction is completed, put it in the refrigerator overnight to completely precipitate the solid, filter Afterwards, they were washed three times with water and three times with absolute ethanol to finally obtain a pale yellow solid (0.256g), with a yield of 59.6%. The infrared spectrogram (FT-IR) is shown in Figure 8, FT-IR (KBr, cm ⁻¹ ): 3442(-OH), 2932, 2851(CH), 2200(C≡N), 1615(C=C), 1561(C=N), 1103(SO-Hg), 497(S-Hg);

I. Preparation of Cd-containing complex VBT-Cd: This reaction is the same as the synthesis method of VBT-Hg, HgCl ₂ is replaced by 0.134g (0.55mmol) Cd(CH ₃ COO) _2· 2H ₂ O, and the same After post-treatment, 0.225 g of golden yellow solid was obtained with a yield of 56.4%. The infrared spectrum (FT-IR) is shown in Figure 8, FTIR (KBr, cm ^-1 ): 3441(-OH), 2931, 2851(CH ), 2203(C≡N), 1613(C=C), 1563(C=N), 1102(SO-Cd), 498(S-Cd);

J. Preparation of the polymeric complex BDTT-VBT-Hg: Add 0.254 g (0.30 mmol) of the above-mentioned mercury complex VBT-Hg monomer and 2,6-dibromo-4,8-di (5-(2-Ethyloctyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (BDTT) donor monomer 0.221g (0.30mmol), add 0.00425g (0.019mmol) catalyst palladium acetate (Pd(CH3COO) 2) and 0.0275g (0.09mmol) tris (2-tolyl) phosphine, add 7mL DMF and 3mL triethylamine after dry treatment under inert gas protection atmosphere Stir and dissolve, then heat to reflux for 48 hours, cool after the reaction stops, filter, wash several times with absolute ethanol and put into a vacuum oven to dry to obtain 0.251 g of brown-green solid powder with a yield of 58.6%. -IR) See Figure 9, FTIR (KBr, cm ^-1 ): 3440 (-OH), 2932, 2850 (CH), 2200 (C≡N), 1613 (C=C), 1558 (C=N) , 1100 (SO-Ni), 494 (S-Hg).Mn=10.10×103g/mol, PDI=1.84;

K. Preparation of polymeric complex BDTT-VBT-Cd: The synthetic method of this polymer is the same as that of BDTT-VBT-Hg, only need to change the Hg complex VBT-Hg into Cd complex VBT-Cd 0.254g ( 0.30mmol), to obtain dark brown solid powder 0.234g, yield 57.1%, infrared spectrum (FT-IR) see accompanying drawing 9, FTIR (KBr, cm ^-1 ): 3438 (-OH), 2930, 2851 ( CH), 2205(C≡N), 1611(C=C), 1557(C=N), 1101(SO-Cd), 495(S-Cd).Mn=10.49×103g/mol, PDI=1.89.

Example 2:

Determination of thermogravimetric analysis (TGA) curves of two kinds of butoxybenzodithiophene derivatives mercury, cadmium homopolymer complexes BDTT-VBT-Hg, BDTT-VBT-Cd, method: SDTQ600 thermogravimetric analyzer, N ₂ Under protection, the test was carried out at a heating rate of 20°C/min, and the test results are shown in Figure 10.

Example 3:

)，柱温箱温度80℃，以DMF为流动相，聚苯乙烯溶液作参比，流速为1.00mL/min进行测试，测试结果如表1：Determination of the molecular weight of two butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes BDTT-VBT-Hg, BDTT-VBT-Cd, the method is gel permeation chromatography (GPC): use Waters-1515 model Gel permeation chromatography, the separation column is waters styragel columns (103,104,

), the temperature of the column oven was 80°C, DMF was used as the mobile phase, polystyrene solution was used as a reference, and the flow rate was 1.00mL/min for the test. The test results are shown in Table 1:

Table 1 Molecular weight test of two kinds of butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes

Example 4:

Photovoltaic performance test of two butoxybenzodithiophene derivatives mercury, cadmium homopolymeric complexes BDTT-VBT-Hg, BDTT-VBT-Cd: current density-current (JV) curve test light source simulated by xenon lamp Strong 100mW/cm ² AM1.5G sunlight, change the voltage through Keithley 2400 digital source meter and record the change value of current with voltage; external quantum efficiency (IPCE) test is provided by Oriel Cornerstone monochromator as light source, under short circuit condition Measured, the test interval of the wavelength is 10nm, and the effective working area of DSSCs is 0.25cm ² ; the performance of the dye-sensitized solar cell with two polymeric complex dye sensitizers BDTT-VBT-Hg and BDTT-VBT-Cd is measured Parameters and photoelectric conversion efficiency, the battery current density-voltage (JV) curve is shown in Figure 11, and the battery external quantum efficiency (IPCE) curve is shown in Figure 12; Table 2 is their photovoltaic performance and photoelectric conversion efficiency test results:

Table 2 Photovoltaic performance test of two kinds of butoxybenzodithiophene derivatives mercury and cadmium homopolymeric complexes

Claims (2)

1. The two butoxy benzodithiophene derivative mercuric and cadmium homopolymerization complexes BDTT-VBT-Hg and BDTT-VBT-Cd have the following structural formulas:

the preparation method of the two butoxybenzodithiophene derivative mercuric and cadmium homopolymerization complexes BDTT-VBT-Hg and BDTT-VBT-Cd comprises the following steps:

(1) Preparation of 1,2-dithienyl-1,2-dione:

reacting thiophene-3-carbaldehyde with K ₂ CO ₃ Adding DMSO and 3-benzyl-5- (2-hydroxyethyl) -4-methylthiazolium bromide into a single-neck flask according to the mol ratio of 1.0: 1.2-1.0: 1.8, heating and refluxing for 34-38 hours in the atmosphere of carbon dioxide, cooling to room temperature after the reaction is finished, adding water, extracting with diethyl ether for three times, adding anhydrous magnesium sulfate for drying, filtering and spin-drying to obtain a light yellow liquid, and performing column separation on the obtained crude product by using a mixed solution of ethyl acetate and petroleum ether with the volume ratio of 1: 10-1: 15 as an eluent to obtain a golden yellow needle-shaped solid 1,2-dithiophene-1,2-diketone;

(2) Benzo [1,2-b:6,5-b' ] dithiophene-4,5-dione preparation:

dichloromethane and 1,2-dithiophene-1,2-diketone are added into a single-neck flask and dissolved by stirring, and then FeCl is slowly added ₃ Reacting at 45 ℃ for 22-26 h, and standing after the reaction is finishedPlacing for 1-2 h, adding deionized water, extracting for three times by using dichloromethane, collecting an organic phase, drying by using anhydrous magnesium sulfate, filtering, and then carrying out spin-drying to obtain a black flocculent solid, wherein the obtained crude product is subjected to column chromatography by using a mixed solution of ethyl acetate and petroleum ether as an eluent in a volume ratio of 1: 10-1: 15 to obtain black needle-shaped solid benzo [1,2-b:6,5-b']Dithiophene-4,5-dione;

(3) 2,7-dibromobenzo [1,2-b:6,5-b' ] dithiophene-4,5-dione preparation:

mixing benzo [1,2-b:6,5-b' ] dithiophene-4,5-dione and NBS are added into a single-neck flask according to the mol ratio of 1.0: 1.8-1.0: 2.4, DMF is added, then reaction is carried out for 22-26 h at 70 ℃, after the reaction is finished, the mixture is cooled to room temperature, poured into water and kept stand for 30-60 min, and after suction filtration and drying, light blue solid 2,7-dibromobenzo [1,2-b is obtained: 6,5-b' ] dithiophene-4,5-dione;

(4) 2,7-divinylbenzo [2,1-b: preparation of 3,4-b' ] dithiophene:

in a single-neck flask, 2,7-dibromobenzo [1,2-b:6,5-b '] dithiophene-4,5-dione and potassium vinyltrifluoroborate, adding cesium carbonate, 2-dicyclohexylphosphorus-2', 6 '-diisopropoxy-1,1' -biphenyl and palladium chloride, then slowly adding a tetrahydrofuran solution dropwise, heating and refluxing for 22-26 h under the protection of nitrogen, cooling to room temperature after the reaction is finished, removing excess solvent by reduced pressure distillation, pouring into water and extracting with ethyl acetate for three times, collecting an organic phase, drying with anhydrous magnesium sulfate, filtering, spin-drying, performing column separation on the obtained crude product by using a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1: 10-1: 14 as an eluent to obtain a black solid 2,7-divinylbenzo [2,1-b:3,4-b' ] dithiophene;

(5) 4,5-dibutoxy-2,7-divinylbenzo [2,1-b: preparation of 3,4-b' ] dithiophene:

2,7-divinylbenzo [2,1-b:3,4-b' ] dithiophene and n-bromobutane are added into a three-neck flask according to the molar ratio of 1.0: 0.8-1.0: 1.2, tetrabutylammonium bromide, sodium hydrosulfite and tetrahydrofuran solution are added, KOH solution is slowly dripped through a constant pressure dropping funnel under the protection of nitrogen, after the dripping is finished, the mixture reacts at 80 ℃ for 46-50 h, the mixture is cooled to room temperature after the reaction is finished, ethyl acetate is used for extraction for three times, organic phase is collected and dried by anhydrous magnesium sulfate, a yellowish liquid crude product is obtained after filtration and spin drying, the obtained crude product is subjected to column separation by using a mixed solution of ethyl acetate and petroleum ether with the volume ratio of 1: 36-1: 44 as an eluent, and a yellow liquid 4,5-dibutoxy-2,7-divinyl benzene [2,1-b:3,4-b' ] dithiophene;

(6) Preparation of 5-formyl-8-quinolinol:

adding 8-hydroxyquinoline and absolute ethyl alcohol into a three-neck flask, adding a sodium hydroxide solution through a constant-pressure separating funnel under the stirring state, heating to 80 ℃ for reflux after complete dissolution, slowly adding chloroform through the constant-pressure separating funnel, wherein the molar ratio of the 8-hydroxyquinoline to the chloroform is 1.0: 2.0-1.0: 2.4, reacting for 22-26 hours, removing the ethyl alcohol and the chloroform through reduced pressure distillation after the reaction is finished, pouring distilled water, neutralizing with dilute hydrochloric acid until the pH value is 7.0, performing suction filtration to obtain a brown solid, performing vacuum drying to obtain a brown blocky object, grinding to be powdery, continuously drying, washing with petroleum ether, cooling a washing solution, recrystallizing the remaining solid with absolute ethyl alcohol twice after filtering a supernatant, and drying to obtain an orange pink filamentous crystal 5-formyl-8-hydroxyquinoline;

(7) Preparation of 2-cyano-3- (8-hydroxyquinolin-5-yl) acrylic acid:

adding 5-formyl-8-hydroxyquinoline and cyanoacetic acid into a three-necked flask according to the molar ratio of 1.0: 1.2-1.0: 1.8, adding acetic acid and acetonitrile, stirring until the acetic acid and the acetonitrile are dissolved, adding piperidine after the acetic acid and the acetonitrile are dissolved, reacting at 90 ℃ for 34-38 hours, after the reaction is finished, spin-drying the solvent and drying, grinding the solid into powder, washing the powder with trichloromethane for three times, drying the solid, and recrystallizing the solid with ethanol for two times to obtain orange powder 2-cyano-3- (8-hydroxyquinoline-5-yl) acrylic acid;

(8) Preparing a metal complex VBT-Hg:

a three-necked flask was charged with 4,5-dibutoxy-2,7-divinylbenzo [2,1-b:3,4-b']Dithiophene and 2-cyano-3- (8-hydroxyquinolin-5-yl) acrylic acid, THF was then added, followed by dissolution at 40 ℃ and HgCl ₂ Dissolving in anhydrous methanol, slowly dropwise adding through a constant-pressure funnel, reacting at 75 ℃ for 22-26 h, cooling to room temperature after the reaction is finished, putting into a refrigerator for overnight, filtering, washing with water for three times and washing with anhydrous ethanol for three times respectively to finally obtain a light yellow solid Hg-containing complex VBT-Hg;

(9) Preparing a metal complex VBT-Cd:

the synthesis method of the complex VBT-Cd is the same as that of VBT-Hg, and HgCl is added ₂ To Cd (CH) ₃ COO) ₂ ·2H ₂ O, finally obtaining a golden yellow solid Cd-containing complex VBT-Cd;

(10) Preparation of polymer complex BDTT-VBT-Hg:

adding Hg-containing complexes VBT-Hg and 2,6-dibromo-4,8-di (5- (2-ethyloctyl) thiophene-2-yl) benzo [1,2-b:4,5-b '] dithiophene (BDTT) with the molar ratio of 1.0: 0.8-1.0: 1.2 into a single-neck flask, sequentially adding zinc powder, triphenylphosphine, bis (triphenylphosphine) nickel dichloride, 2,2' -bipyridine and DMF, refluxing for 46-50 h under the protection of nitrogen according to Heck polymerization reaction, filtering after the reaction is finished, fully washing with absolute ethyl alcohol, and drying to obtain a brown green solid polymerization complex BDTT-VBT-Hg;

(11) Preparing a polymerization complex BDTT-VBT-Cd:

the synthesis method of the polymer complex BDTT-VBT-Cd is the same as that of the BDTT-VBT-Hg, and the Hg-containing complex VBT-Hg is replaced by the metal complex VBT-Cd to finally obtain the deep brown solid polymer complex BDTT-VBT-Cd.

2. The use of two butoxybenzodithiophene derivative mercuric, cadmium homo-complexes BDTT-VBT-Hg, BDTT-VBT-Cd according to claim 1 as dye sensitizers in dye sensitized solar cells.

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