PL237407B1 - Donor-acceptor system containing modified amine, amide or imide multi-layered fullerenes and ferrocene and method for producing it - Google Patents

Abstract

The subject of the application is a donor-acceptor system of formula 1, in which A is a group that is connected to a multilayer fullerene by any bond and is connected to ferrocene via an amide or imide bond. This application also concerns a method for preparing the donor-acceptor system of Formula 1, the donor systems used in this method, as well as methods for preparing these donor systems and using the donor-acceptor system.

Description

Description of the invention

The subject of the invention is the functionalization of multilayer fullerenes (carbon nanobubbles) with the use of amines, amides and imides, in particular a donor-acceptor system containing multilayer fullerenes and ferrocene modified with an amine, amide or imide, and a method of its preparation. Functionalization of multilayer fullerenes is aimed at improving their dispersion properties, as well as the possibility of their further modification to obtain donor-acceptor systems containing derivatives of multilayer fullerenes and ferrocene, which can be used in the construction of photovoltaic systems.

Multilayer fullerenes, or carbon nano-onions (CNOs), were first discovered in 1980 by Sumio lijima during transmission electron microscopy of carbon material (S. lijima, J. Microsc., 119.99, ( 1980)). They aroused interest among scientists only when Ugarte, in 1992, obtained them on a larger scale, subjecting carbon material to the action of an electron beam inside a TEM microscope (D. Ugarte, Nature, 359, 707, (1992)). Multilayer fullerenes are made of spherically closed one in another graphene layers, the base of which is the simplest fullerene - ICeo. Due to their layering, they have been called carbon nanobubbles (CNOs). Carbon nanobubbles can be obtained by various methods, but the most popular and leading to a relatively homogeneous material with a grain diameter of 5-6 nm (6-8 carbon layers) is the Kuznetsov method, consisting in annealing of the nanodiamond in an atmosphere of helium at a temperature of approx. 1650 ° C (VL Kuznetsov et al., Chem. Phys. Lett., 222, 343 (1994)). Due to the lack of commercial availability, carbon nanobubbles have not gained as much popularity as the above-mentioned lower fullerenes or carbon nanotubes, but they have a high application potential, as they can be used as an electrode material in capacitors, fuel cells, lithium-ion batteries, and also as an active material in photovoltaics and as biosensors. As an intermediate material, between nanotubes and fullerenes, they have the advantages of both of them, characterized by, among others, high thermal resistance and high reactivity. The limitation of the use of carbon nanomaterials in various fields of chemistry and material engineering is their low solubility in organic and inorganic solvents. To increase the dispersion, carbon nanobubbles can be functionalized with various compounds, and the number of published works on CNOs modification is still small compared to other nanostructures, such as graphene, fullerenes or nanotubes. The best known types of functionalization are based on the Diels-Alder reaction.

The active layer in a photovoltaic cell consists of an electron donor and an acceptor, between which the charge is separated. The operation of the donor-acceptor (D / A) junction is based on the differences in the electron affinity and in the ionization potentials of the two different materials. One of the first reports on donor-acceptor systems was the revolutionary idea of an organic photovoltaic cell, presented in 1986 by CW Tang, in which the electron donor was copper phthalocyanine and the electron acceptor was a perylene derivative (CW Tang, Appl. Phys. Lett. 48, 183, (1986)). Since then, a lot of information has appeared in the literature about the diversity of D / A connectors. The electron donor is usually polymers or small molecules that readily absorb light, thereby causing the electron to excite and transfer it to the electron acceptor. This, in turn, has the ability to accept an electron, but also provides for electron-hole charge separation. The compounds most commonly used as electron acceptors are fullerene derivatives.

In the literature, there have been examples of reactions for the preparation of polyhedral fullerenes containing amino or amide groups (AS Rettenbacher et al., Chem. Eur. J "12, 376, (2006); A. Palkar, Chem. Mater., 20, 1685, ( 2008)). At the same time, many ways of synthesizing donor-acceptor systems containing ferrocene derivatives and various carbon materials are described. It is also known from the publication (Chem. Eur. J "15, 4419, (2009)) the synthesis of the donor-acceptor system containing carbon nanobubbles and ferrocene derivatives

As there is still a need in the art for new donor-acceptor systems containing functionalized carbon nanobubbles and ferrocene, it was an object of the present invention to develop such systems and a method for their preparation.

According to the present invention, a new, hitherto unpublished method for the preparation of donor-acceptor systems containing polyhedral fullerenes and ferrocene modified with amine, amide and imide has been proposed.

PL 237 407 Β1

Thus, the present invention relates to the donor-acceptor system of formula 1

Formula 1

A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and group A is selected from

PL 237 407 Β1

Preferably, the donor acceptor injury of Formula 1 is selected from the group of

The invention also relates to a process for the preparation of the donor-acceptor system of formula 1

Formula 1 in which,

means multilayer fullerene

PL 237 407 Β1

A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and group A is selected from

characterized by the steps in which:

- multilayer fullerene is functionalized to form a donor system containing an amino, amide or imide group,

- the functionalized fullerene donor system is reacted with ferrocenoic acid of formula

to form a donor-acceptor system of Formula 1.

Preferably, the reaction of the functionalized fullerene donor system with ferrocenoic acid is carried out in a solvent such as toluene or dimethylformamide and at a temperature of 70-90 ° C.

Preferably, the functionalized fullerene donor system is reacted with ferrocenoic acid for a period of 18-26 hours.

The invention also relates to a donor system selected from the following:

PL 237 407 Β1 in which,

means multilayer fullerene,

The invention also relates to a method for producing a donor system of formula

PL 237 407 Β1

characterized in that the multilayer fullerene and 4-aminobenzylamine are reacted in the presence of isopentyl nitrite and without the use of a solvent.

The invention also relates to a method for producing a donor system of formula

wherein,

denotes multilayer fullerene, characterized in that it comprises the steps in which

- the reaction of phenol and 1,2-dicyanobenzene is carried out to obtain a compound of the formula

NH

- thereafter the compound obtained is reacted with a compound of formula

nh ₂

The invention also relates to a method for producing a donor system of formula

PL 237 407 Β1

characterized in that it includes the steps in which

- multilayer fullerene is oxidized with a solution of nitric acid (V),

- the oxidized fullerene obtained is reacted with thionyl chloride in the presence of zinc chloride as catalyst, and

- the obtained fullerene modified with reactive -COCI groups is reacted with an aqueous solution of ammonia.

The invention also relates to a method for producing a donor system of formula

characterized in that the multilayer fullerene is reacted with maleimide in the presence of zinc chloride as catalyst.

The invention also relates to the use of the donor-acceptor system of formula 1

Formula 1 in which,

means multilayer fullerene,

PL 237 407 Β1

A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and group A is selected from

for the production of an active layer in photovoltaic cells.

Brief description of the figures in the drawing

Fig. 1. Photo of a 0.5 mg / ml solution of polyhedral fullerenes in toluene: (a) CNOs, (b) CNOs / 4aminobenzylamine, (c) CNOs / amine derivative.

Fig. 2. Scanning electron microscopy (SEM) pictures for the following samples: (a) CNOs, (b) CNOs / 4-aminobenzylamine, (c) CNOs / amine derivative.

Fig. 3. Chronovoltammetric curves recorded in a three-electrode system in acetonitrile / toluene (1: 4, v / v) in the potential range of -1.0 4- 1.0 V at a polarization rate constant of 50 mV / s for the following samples: ( a) ferrocene carboxylic acid - Fc-COOH, (b) CNOs / 4-aminobenzylamine / Fc, (c) CNOs / amine derivative / Fc.

Fig. 4. Photo of 0.5 mg / ml solution of polyhedral fullerenes in toluene: (a) CNOs, (b) CNOs / amide.

Figure 5. Scanning Electron Microscope (SEM) pictures for the following samples: (a) CNOs, (b) CNOs / amide.

Fig. 6. Chronovoltammetric curves recorded in a three-electrode system in a mixture of acetonitrile / toluene (1: 4, v / v) in the potential range of -1.0 4.0 V at a polarization rate constant of 50 mV / s for the following samples: ( a) ferrocene carboxylic acid - Fc-COOH, (b) CNOs / amide / Fc.

Fig. 7. Photo of a 0.5 mg / ml solution of polyhedral fullerenes in toluene: (a) CNOs, (b) CNOs / maleimide.

Fig. 8. Scanning Electron Microscope (SEM) pictures for the following samples: (a) CNOs, (b) CNOs / maleimide.

Fig. 9. Chronovoltammetric curves recorded in a three-electrode system in acetonitrile / toluene (1: 4, v / v) in the potential range of -1.0 4.0 V at a polarization rate constant of 50 mV / s for the following samples: ( a) ferrocene carboxylic acid k Fc-COOH, (b) CNOs / maleimide / Fc.

EXAMPLES

Reagents and apparatus:

Polyhedral fullerenes with a diameter of about 5-6 nm (6-8 carbon layers) used in the present invention were obtained by annealing diamond nanoparticles (Carbodeon μθί3mond Molto with a diameter of 4.2 ± 0.5 nm, nanodiamond content> 97% by weight) with using the method proposed by Kuznetsov (VL Kuznetsov et al., Chem. Phys. Lett., 222, 343 (1994)) and described in the patent application in 2009 (LIS 2009/0220407 A1, Echegoyen et al. "Preparation and functionalization of carbon nano-onions).

The following reagents were used to prepare the following donor acceptor systems of the present invention: 4-aminobenzylamine (~ 99%); phenol (> 99%); 1,2-dicyanobenzene (~ 98%); isopentyl nitrite (~ 96%); thionyl chloride (> 99%); aqueous ammonia solution (25% CZDA); maleimide (~ 99%); zinc chloride (> 98%); nitric acid (65%); ferrocene carboxylic acid

PL 237 407 Β1 (97%); acetone (99.5% CZDA); toluene (> 99.7% CZDA); 2-propanol (CZDA); deionized water with a resistance of 18.2 Ω, dimethylformamide (99.9%).

In order to confirm the obtaining of the donor-acceptor systems according to the present invention, the following test equipment was used:

Bruker Avance II NMR spectrometer - ¹ H NMR spectra were recorded at 400 MHz, solvent was deuterated benzene (CeDe), chemical shifts are given in ppm;

- Nicolet iN10 MX FTIR microscope - FTIR spectra were recorded in the range of 4000-700 cm ¹ using a liquid nitrogen cooled array detector;

- SEM TFP 2017/12 Inspect S50 FEI microscope - SEM photos were taken at 1000x magnification with a resolution of 100 μπι, samples were applied to gold foil;

- Autolab potentiostat / galvanostat - voltammetric curves were recorded in a three-electrode system in the acetonitrile / toluene mixture (1: 4, v / v) in the potential range of -1.0 4.0 V at a constant polarization rate of 50 mV / s;

- BANDELIN electronic ultrasonic bath - ultrasound with the power of 35 kHz, 80 / 320W was used to disperse the suspensions;

- centrifuge HERMLE Labortechnik GmbH - used speed 6000 rpm.

EXAMPLE 1

Preparation of the CNOs / 4-aminobenzylamine donor system (1) and then obtaining the complete CNOs / 4-aminobenzylamine / Fc donor-acceptor junction (2)

ABOUT

Reaction scheme for the synthesis of a donor-acceptor system containing carbon nanobubules modified with 4-aminobenzylamine and ferrocene (CNOs / 4-aminobenzylamine / Fc).

Stage I: The first stage consists in the reaction of carbon nanobubules with 4-aminobenzylamine in the presence of isopentyl nitrite. CNOs (200 mg) and 4-aminobenzylamine (123 mg) were placed in a 25 ml round bottom flask without the use of any solvent. The flask with the contents described above was placed on a magnetic stirrer and connected to a reflux condenser. This was mixed well and isopentyl nitrite (120 mg) was slowly added as a reaction catalyst. The contents of the flask were then slowly brought to 60 ° C and heated for 26 hours keeping the temperature constant. After completion of the reaction, the mixture was brought to room temperature and then washed several times with deionized water and then with acetone. The purified pellet from the reaction substrate was dried in an oven in an air atmosphere at 50 ° C for 12 hours. As a result of the reaction, the CNOs / 4-aminobenzylamine system (1) was obtained, which is a donor system and, at the same time, a substrate in the second stage of the reaction.

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 6.28; 5.35; 4.21; 4.03; 3.75; 3.50; 2.36; 2.18; 2.05; 1.83; 1.56; 1.27; 0.85.

FTIR (cm ¹ ): 3378 (vn-h), 2942 (vsp ² ch), 1564 (5n-h, vc = o), 1489 (Vc = c), 1170 (von), 782 (5n-h).

Fig. 1 shows a comparison of the dispersion results for a 0.5 mg / ml solution of polyhedral fullerenes in toluene: CNOs / 4-aminobenzylamine (1) -Fig. 1b and CNOs-Fig. 1a. The presented photos show that the starting carbon nanobubbles (unmodified material) are characterized by lower dispersibility compared to functionalized CNOs. This is evidenced by the sedimentation process visible in the photos for pure polyhedral fullerenes (Fig. 1a) and the stability of the solution of modified CNOs (Fig. 1b).

Fig. 2 shows pictures taken with a scanning electron microscope (SEM) to compare the properties of unmodified nanobubules (Fig. 2a) and modified CNOs / 4-aminobenzylamine (Fig. 2b). An increase in dispersion can be seen in Fig. 2b and thus a reduction in the amount of aggregates present in the sample.

Step II: 80 mg of 4-aminobenzylamine-modified polyhedral fullerenes and 44 mg of ferrocene carboxylic acid were placed in a round bottom flask, then ml of dimethylformamide was added. The mixture was heated to 90 ° C and stirred for 20 hours. After the reaction is complete, the mixture is

PL 237 407 Β1 was brought to room temperature, then washed several times with deionized water, and then with acetone. In order to accelerate sedimentation, the mixture was centrifuged and the supernatant solution was removed. The operation was repeated several times. The purified post-reaction substrate pellet was dried in an oven under air at 50 ° C for 12 hours (CNOs / 4-aminobenzylamine / Fc (2)).

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 6.29; 5.32; 4.16; 4.03; 3.76; 3.62; 3.50; 2.46; 2.36; 2.18; 2.02;

1.86; 1.61; 1.26; 0.90.

FTIR (cm ¹ ): 3347 (vn-h), 2923 (v sp ² ch), 1561 (5n-h, vc = o), 1504 (vc = c, vc = c _F e ²⁺ ), 1166 (von ), 796 (5n-h).

Fig. 3 shows a cyclic chronovoltammetric curve - 3b showing the attachment of ferrocene carboxylic acid (as donor) to previously functionalized polyhedral fullerenes (as acceptor). The characteristic oxidation and reduction peaks indicate the electroactivity of the obtained donor-acceptor junction (CNOs / 4-aminobenzylamine / Fc).

EXAMPLE 2

Preparation of the CNOs / amino derivative (3) donor system, followed by the preparation of the complete donor-acceptor junction (CNOs / amino derivative / Fc (4)) according to the following reaction scheme.

Scheme of the synthesis reaction of the donor-acceptor system based on the amine derivatives of multilayer fullerenes and ferrocene (CNOs / amine derivative / Fc).

Stage I: 125 mg of phenol and 170 mg of 1,2-dicyanobenzene were placed in a 50 ml round bottom flask. The flask with the contents described above was placed on a magnetic stirrer and connected to a reflux condenser. The mixture was stirred and brought to 130 ° C while heating the reaction mixture for 6 hours.

Step II: In the second step, 325 mg of 4-aminobenzylamine modified carbon nanobubbles (CNOs / 4-aminobenzylamine (1)) obtained in step I of Example 1 were added to the above reaction mixture and dissolved in 5 ml of toluene. The contents of the flask were then slowly stirred and brought to 100 ° C and heated for 24 hours keeping the temperature constant. After completion of the reaction, the mixture was brought to room temperature and then washed several times with deionized water and then with acetone. The purified pellet from the reaction substrate was dried in an oven in an air atmosphere at 50 ° C for 12 hours. As a result of the reaction, the CNOs / amino derivative system (3) was obtained, which is a donor system and, at the same time, a substrate in the second stage of the reaction.

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 4.26; 3.57; 3.01; 2.37; 1.86; 1.55; 1.32; 0.92

FTIR (cm ¹ ): 3352 (vn-h), 2925 (v _sp ² ch), 1651 (5n-h), 1502 (vc = c), 1174 (von), 834; 757 (5n-h).

Fig. 1 shows a comparison of the dispersion results for a 0.5 mg / ml solution of polyhedral fullerenes in toluene: CNOs / amine derivative (3) - Fig. 1c and CNOs - Fig.la. The presented photos show that the starting carbon nanobubbles (unmodified material) are characterized by lower dispersibility compared to functionalized CNOs. This is evidenced by the sedimentation process visible in the photos for pure polyhedral fullerenes (Fig. 1a) and the stability of the solution of modified CNOs (Fig. 1c).

Fig. 2 shows pictures taken with a scanning electron microscope (SEM) to compare the properties of unmodified nanobubbles (Fig. 2a) and carbon nanobubbles containing amino groups (Fig. 2c). An increase in dispersion can be seen in Fig. 2c and thus a reduction in the amount of aggregates present in the sample.

Stage III: Reaction mixture containing 80 mg of amino derivative modified carbon nanobubbles and 40 mg of ferrocene carboxylic acid in 5 ml of toluene

PL 237 407 µ1 was placed in a round bottom reflux flask, then stirred and heated to a temperature equal to 90 ° C. The reaction was run under constant conditions for 24 hours. After completion of the reaction, the mixture was brought to room temperature and then washed several times with deionized water and then with acetone. In order to accelerate sedimentation, the mixture was centrifuged and the supernatant solution was removed. The operation was repeated several times. The purified pellet from the reaction substrate was dried in an oven in an air atmosphere at 50 ° C for 12 hours. As a result of the reaction, carbon nanobubules containing amino groups and a ferrocene derivative (CNOs / amino derivative / Fc (4)) were obtained.

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 4.25; 3.58; 3.00; 2.11; 1.54; 1.40; 1.24; 0.95; 0.87

FTIR (cm ¹ ): 3302 (vn-h), 2924 (v _sp ² ch), 1661 (5n-h), 1561 (vc = c), 1090 (von), 837; 751 (5n-h).

Fig. 3 shows a cyclic voltammetry curve - 3c showing the attachment of ferrocene carboxylic acid (as donor) to previously functionalized polyhedral fullerenes (as acceptor). The characteristic oxidation and reduction peaks indicate the electroactivity of the obtained donor-acceptor junction (CNOs / amino derivative / Fc).

EXAMPLE 3

Preparation of the CNOs / amide donor system (1), followed by preparation of the complete donor-acceptor junction (CNOs / amide / Fc (2)) according to the following reaction scheme.

Reaction scheme for the synthesis of the donor-acceptor system based on amide multilayer derivatives of fullerenes and ferrocene (CNOs / amide / Fc), including the initial formation of the donor system (CNOs / amide (1)), and then obtaining the complete donor-acceptor junction (CNOs / amide / Fc (2)):

Stage I: This stage involves the oxidation of CNOs in the presence of a 3M nitric acid solution by the method developed by A. S. Rettenbacher et. al., Chem. Eur. J., 12, 376, (2006).

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 6.09; 4.23; 3.58; 2.11; 1.67; 1.40; 0.96.

Stage II: 200 mg of CNOs oxidized in Stage I, dispersed in 20 ml of dimethylformamide (DMF), were placed in a round-bottom flask. The reaction flask was placed on a magnetic stirrer and connected to a reflux condenser. After mixing thoroughly, 20 mg of zinc chloride was used as a catalyst for the reaction, then thionyl chloride (120 mg) was added portionwise. The contents of the flask were slowly brought to 70 ° C and heated for 6 hours, keeping the synthesis conditions constant. During the reaction, CNOs were obtained with -COCI groups, which are characterized by high reactivity.

Stage III: In the next stage, a 25% aqueous ammonia solution (0.5 ml) was added to the mixture obtained in stage II. The mixture was placed on a magnetic stirrer and heated to reflux, keeping the temperature constant at 110 ° C for 24 hours. At this stage, carbon nanobubules functionalized with amide groups (CNOs / amide (1)) were obtained.

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 5.30; 4.21; 3.50; 3.01; 2.35; 2.18; 2.15; 1.86; 1.32; 0.91.

FTIR (cm ¹ ): 3396 (vn-h), 2924 (v _sp ² ch), 1613 (5n-h, vc = o), 1400 (vc = c) 1067 (vc-n), 867 (5n-h ).

Fig. 4 shows a comparison of the dispersion results for a 0.5 mg / ml solution of polyhedral fullerenes in toluene: CNOs - Fig. 4a and CNOs / amide (1) - Fig. 4b. The presented photos show that the starting carbon nanobubbles (unmodified material) are characterized by lower dispersibility compared to functionalized CNOs. This is evidenced by the sedimentation process visible in the photos for pure polyhedral fullerenes (Fig. 4a) and the stability of the modified CNOs suspension (Fig. 4b).

Fig. 5 shows pictures taken with a scanning electron microscope (SEM) to compare the properties of unmodified nanobubbles (Fig. 5a) and carbon nanobubules containing amide groups (Fig. 5b). An increase in dispersion can be seen in Fig. 5b and thus a reduction in the amount of aggregates present in the sample.

Stage IV: 80 mg of amide-modified carbon nanobubbles and 56 mg of ferrocene carboxylic acid in 5 ml of DMF were placed in a round-bottom flask. The mixture was placed on a magnetic stirrer and heated to reflux, keeping the temperature constant

PL 237 407 Β1 at 90 ° C for 20 hours. After cooling the system to room temperature, it was washed several times with deionized water and then with acetone. In order to accelerate sedimentation, the mixture was centrifuged and the supernatant solution was removed. The operation was repeated several times. The purified pellet from the reaction substrate was dried in an oven under an air atmosphere at 50 ° C for 12 hours (CNOs / amide / Fc (2)).

¹ HNMR (400 MHz, C ₆ D ₆ , δ, ppm): 5.35; 4.13; 4.03; 3.76; 3.50; 2.18; 2.05; 1.86; 1.58; 1.27; 0.89.

FTIR (cm ¹ ): 3354 (vn-h), 2923 (v sp ² & h), 1593 (5n-h, voo), 1416 (voc, vc-c PierścFe ²⁺ ), 1041 (von), 799 (8n -h).

Fig. 6 shows a cyclic voltammetry curve - 6b, showing the attachment of ferrocene carboxylic acid (as donor) to previously functionalized polyhedral fullerenes (as acceptor). The characteristic oxidation and reduction peaks indicate the electroactivity of the obtained donor-acceptor junction (CNOs / amide / Fc). EXAMPLE 4

Preparation of the CNOs / maleimide donor system (1), then preparation of the complete donor-acceptor junction (CNOs / maleimide / Fc (2)) according to the following reaction scheme.

Scheme of the synthesis of a donor-acceptor system based on carbon nanobubules modified with maleimide and ferrocene (CNOs / maleimide / Fc).

The CNOs / maleimide donor-acceptor system (1) is preferably obtained by reacting polyhedral fullerenes and maleimide using zinc chloride as catalyst and toluene as solvent. The obtained product was reacted with ferrocene carboxylic acid to obtain a donor-acceptor junction (CNOs / maleimide / Fc (2)).

The method of producing this system comprises initially forming a donor system (CNOs / maleimide (1)) and then obtaining a complete donor-acceptor junction (CNOs / maleimide / Fc (2)):

Stage I: In the first stage, 200 mg of carbon nanobubbles were used to react with 98.1 mg of maleimide. The reaction mixture with 20 mg of zinc chloride (catalyst) was placed in a round bottom flask under reflux, 10 ml of toluene were added. The contents of the flask were then slowly brought to 110 ° C with slow stirring. It was heated for 26 hours keeping the temperature constant. After completion of the reaction, the mixture was brought to room temperature and then washed several times with deionized water and then with acetone. The purified pellet from the reaction substrate was dried in an oven in an air atmosphere at 50 ° C for 12 hours. As a result of the reaction, CNOs / maleimide (1) was obtained, which is a donor system and, at the same time, a substrate in the second stage of the reaction.

¹ H NMR (400 MHz, C ₆ D ₆ , δ, ppm): 5.50; 4.26; 3.56; 2.32; 1.81; 1.62; 1.55 1.34; 0.91.

FTIR (cm ¹ ): 3298 (vn-h), 2919 (v _sp ² ch), 1650 (5n-h, vc = o), 1.536 (vc = c) 1302 (vc-n), 833 (5n-h ).

Fig. 7 shows a comparison of the dispersion results for a 0.5 mg / ml solution of polyhedral fullerenes in toluene: CNOs / maleimide - Fig. 7b and CNOs - Fig. 7a. The presented photos show that the starting carbon nanobubbles (unmodified material) are characterized by lower dispersibility compared to functionalized CNOs. This is evidenced by the sedimentation process visible in the photos for pure polyhedral fullerenes (Fig. 7a) and the stability of the solution of modified CNOs (Fig. 7b).

Fig. 8 shows pictures taken with a scanning electron microscope (SEM) to compare the properties of unmodified nanobubules (Fig. 8a) and carbon nanobubules containing maleimide groups (Fig. 8b). An increase in dispersion can be seen in Fig. 8b and thus a reduction in the amount of aggregates present in the sample.

Step II: 40 mg of maleimide-modified polyhedral fullerenes and 24 mg of ferrocene carboxylic acid were placed in a round bottom flask, then 2 ml of toluene was added. I don't

The mixture was heated to 90 ° C and stirred for 24 hours. After cooling the system to room temperature, it was washed several times with deionized water and then with acetone. In order to accelerate sedimentation, the mixture was centrifuged and the supernatant solution was removed. The operation was repeated several times. The purified pellet from the reaction substrate was dried in an oven in an air atmosphere at 50 ° C for 12 hours.

¹ H NMR (400 MHz, C6D6, δ, ppm): 4.26; 3.58; 3.02; 2.11; 1.54; 1; 40; 1.38; 1.25; 0.96; 0.88 FTIR (cm ¹ ): 3013 (v sp ² ch), 1576 (vc = c, vc = o), 1222 (vc-h).

Fig. 9 shows a cyclic voltammetry curve - 9b showing the attachment of ferrocene carboxylic acid (as donor) to previously functionalized polyhedral fullerenes (as acceptor). The characteristic oxidation and reduction peaks indicate the electroactivity of the obtained donor-acceptor junction (CNOs / maleimide / Fc).

Claims (11)

1. Donor-acceptor system of formula 1 Formula 1 A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and the group A is selected from. PL 237 407 Β1 2. The system according to claim 1 like the chosen one Fe ABOUT 3. A method for producing a donor-acceptor system of formula 1 Formula 1 means multilayer fullerene, PL 237 407 Β1 A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and the group A is selected from characterized by the steps of: - multilayer fullerene is functionalized to form a donor system containing an amino, amide or imide group, - the functionalized fullerene donor system is reacted with ferrocenoic acid of formula to form a donor-acceptor system of Formula 1. 4. The method according to p. The process of claim 3, wherein the reaction of the functionalized fullerene donor system with ferrocenoic acid is carried out in a solvent such as toluene or dimethylformamide and at a temperature of 70-90 ° C. 5. The method according to p. The process according to claim 3 or 4, characterized in that the functionalized fullerene donor system is reacted with ferrocenoic acid for a period of 18-26 hours. 6. A donor system selected from the following: PL 237 407 Β1 in which, means multilayer fullerene, 7. A method for producing a donor system of formula PL 237 407 Β1 characterized by reacting the multilayer fullerene and 4-aminobenzylamine in the presence of isopentyl nitrite and without the use of a solvent. 8. A method for producing a donor system of formula characterized in that it comprises the steps in which - the reaction of phenol and 1,2-dicyanobenzene is carried out to obtain a compound of the formula NH - thereafter the compound obtained is reacted with a compound of formula PL 237 407 Β1 9. A method for producing a donor system of formula characterized in that it comprises the steps in which - multilayer fullerene is oxidized with a solution of nitric acid (V), - the oxidized fullerene obtained is reacted with thionyl chloride in the presence of zinc chloride as catalyst, and - the obtained fullerene modified with reactive -COCI groups is reacted with an aqueous solution of ammonia. 10. A method for producing a donor system of formula characterized in that the multilayer fullerene is reacted with maleimide in the presence of zinc chloride as catalyst. PL 237 407 Β1 11. Use of the donor-acceptor system of formula 1 Formula 1 A is a group that is bound by any bond to the multilayer fullerene and is linked to the ferrocene via an amide or imide bond, and group A is selected from for the production of an active layer in photovoltaic cells.