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Impact of benzimidazole functional groups on the n-doping properties of benzimidazole derivatives

  • Chenqing Tang EMAIL logo and Gongchun Li
Published/Copyright: September 7, 2022
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Open Chemistry
From the journal Open Chemistry Volume 20 Issue 1

Abstract

n-Dopants play a crucial role in improving organic electronic devices through controlled doping of organic semiconductors. Benzimidazoline-based dopants have been reported as one of the best solution-processed n-type dopant precursors. In this study, two benzimidazoline-based dopants (BIBDTO and BBIBDTO) were prepared using benzo[1,2-b:4,5-b′]dithiophene as the 2-Ar unit, and their n-doping properties on the fullerene derivative PTEG-2 as the host material were carried out. For BIBDTO and BBIBDTO, respectively, the temperature at which 5% weight loss was achieved was 229 and 265°C. By comparing the ultraviolet-visible absorption spectroscopy, cyclic voltammetry, and density functional theory calculated data, it is found that BBIBDTO has a higher energy level, which is more favorable for charge transfer. Additionally, both the oxidative titration experiments and conductivity characterization of the dopants showed that BBIBDTO was more advantageous at low doping concentrations, and the BBIBDTO-doped PTEG-2 films obtained a conductivity of 0.15 S cm−1 at 10 mol% doping concentration. However, at high dopant concentrations, the dopant volume increases, potentially disrupting the microstructure. The highest conductivity of 0.29 S cm–1 was obtained at a BIBDTO doping concentration of 15 mol%. This study delves into the effect of benzimidazole functional groups on the doping performance of benzimidazoline-based dopant molecules, providing insight into designing novel efficient n-type dopant molecules and further selecting the type of dopant for various doping systems.

Keywords: n-dopants; molecular engineering; energy level structure; conductivity

1 Introduction

Organic semiconductor materials, particularly organic thermoelectric materials, are potential futuristic materials due to their lightweight, high flexibility, and ability to produce large-area devices via solution processing [1,2,3,4]. The comprehensive index for the thermoelectric characteristics of materials is defined by the dimensionless thermoelectric figure of merit ZT = S 2 σT/k, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and k is the thermal conductivity [5,6]. The thermal conductivity of organic thermoelectric materials is typically lower than that of conventional inorganic thermoelectric materials. But the low electrical conductivity of organic materials in their intrinsic state is disadvantageous over inorganic thermoelectric materials, limiting their practical applications. Thus, controlling the electrical conductivity of organic semiconductors is crucial for their applicability. Chemical doping serves as a plausible solution for modulating the electrical conductivity of organic semiconductors, producing transportable carriers by either oxidizing (p-doping) or reducing (n-doping) the organic semiconductor [7,8,9].

Among p-type organic thermoelectric materials, poly [2,5-bis(3-alkylthiophene-2-yl) thiophene(3,2-b)] (PBTTT) doped with Lewis acid or F4TCNQ has resulted in increased conductivity to 250–1100 S cm–1 [10,11,12]. Either p-type or n-type thermoelectric materials are sufficient to construct thermoelectric devices [13]; however, to achieve high conversion efficiencies, the synergy of high-performance p-type and n-type materials is required. This signifies the need to develop high-performance n-type materials in constructing efficient organic thermoelectric devices. Nevertheless, the processability and miscibility of the dopant with the host material, dopant stability, and doping efficiency are the persistent complications in doping of n-type organic thermoelectric materials [7,14,15,16]. Metal complexes and inorganic salts, for example, can only be deposited by thermal evaporation, severely limiting their use in solution-processable organic semiconductors [17,18,19]. Solution-processable aromatic molecules, such as charge-transfer complexes, have also been used as n-type dopants; however, they are unstable in the air [20]. Later, in 2010, a solution-processable and air-stable n-dopant, N-DMBI, was reported by Wei et al. [21] N-DMBI breaks the 2-site C–H bond during thermal annealing, producing radicals and transferring electrons to the host material for n-doping, or releasing hydrogen negative ions (H–) for alkali doping of the host material. It has also shown excellent doping capabilities toward a wide range of semiconductors (as shown in Figure 1) [22,23,24,25]. Although benzimidazoline-based small molecules are widely used as n-type dopants, the role of benzimidazole functional groups is still unclear.

Figure 1 n-Doping pathways of benzimidazole-based dopants.
Figure 1

n-Doping pathways of benzimidazole-based dopants.

We designed and synthesized benzimidazoline-based dopant molecular systems with mono/bi-benzimidazole functional groups and benzo[1,2-b:4,5-b′]dithiophene as the central unit, as well as alkyl side chains of appropriate lengths to ensure dopant solubility. The two types of dopants are BIBDTO (monofunctional group) and BBIBDTO (bifunctional group) (Figure 2). Fullerene derivative PTEG-2 with bis(triethylene)-glycol-type side chains was chosen as the host material owing to its polar side chains, which improve the miscibility of the dopant with the host material. Particularly in solution co-deposited films, the dopant is located in the side chain plane of PTEG-2, reducing the negative effect of dopant volume change on the π–π stacking of PTEG-2 [26,27,28]. The effects of benzimidazole functional groups on the molecular heat treatment temperature of benzimidazoline-based dopants, the single occupied molecular orbital (SOMO) energy level of imidazoline radicals, and their doping properties were revealed using electrochemical tests, ultraviolet (UV)-visible (vis) spectroscopy, and density functional theory (DFT) calculations. Hence, this study provides guidelines for the design of higher-performance benzimidazoline-based dopants.

Figure 2 Schematic for synthetic route of benzimidazoline-based dopants.
Figure 2

Schematic for synthetic route of benzimidazoline-based dopants.

2 Experimental section

2.1 Materials and characterization

Benzo[1,2-b:4,5-b′]dithiophene-4,8-dione was purchased from ENERGY CHEMICAL (98% purity). The complexes, N,N′-dimethyl-o-phenylenediamine [29], 4,8-diethoxybenzo[1,2-b:4,5-′]dithiophene [30], 4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene [31], PTEG-2 [32] were prepared following the literature (for specific synthesis steps, see Supplementary materials).

DFT calculations were carried out for the reduced neutral state, neutral radical state, and oxidized cationic state of benzimidazoline-based dopants to obtain the highest occupied molecular orbital (HOMO), SOMO, and lowest unoccupied molecular orbital (LUMO), respectively. Calculations have been carried out at the (U)B3LYP/6–311++G(d,p) level of theory using the Gaussian16 program package (revision A.03) [33]. The additional information about the instrumentation and characterization are presented in Supporting Information.

2.2 Synthesis of compounds

The molecular structures and synthetic routes of benzimidazoline-based dopants BIBDTO and BBIBDTO are shown in Figure 2.

2.2.1 4,8-Diethoxybenzo[1,2-b:4,5-b′]dithiophene-2-carbaldehyde (compound 2)

Accurately weighed 4,8-diethoxybenzo[1,2-b:4,5-b′]dithiophene (556.7 mg, 2 mmol) and 25 mL anhydrous tetrahydrofuran were taken into a 50 mL dry double-necked flask under nitrogen atmosphere. Then, at –78°C, 2.5 M n-butyllithium solution (2 mmol, 0.8 mL) was slowly added drop wise into the aforementioned mixture. After 1 h, 0.3 mL of anhydrous N,N-dimethylformamide was added, slowly ramped up to room temperature, poured the mixture into deionized water (50 mL), and extracted with dichloromethane. The organic phase was dried with anhydrous MgSO4, and the crude product was purified using silica gel column chromatography using petroleum ether:ethyl acetate (10/1, v/v) eluent. Finally, 551.5 mg of an orange solid product was obtained (89% yield): 1H NMR (500 MHz, CDCl3), δ (ppm): 10.10 (s, 1H), 8.20 (s, 1H), 7.50 (s, 2H), 4.46 (d, J = 7.0 Hz, 2H), 4.36 (d, J = 7.0 Hz, 2H), and 1.56–1.46 (m, 6H) (Figure S2).

2.2.2 4,8-Bis((2-ethylhexyl)oxy)benzo[1,2- b :4,5- b ′]dithiophene-2,6-dicarbaldehyde (compound 4)

Compound 4 was synthesized and purified following the same procedure as that for the preparation of compound 2. Accurately weighed 4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene(446.7 mg, 2 mmol), 2.5 M n-butyllithium solution (2 mmol, 0.8 mL) and 25 mL anhydrous tetrahydrofuran as solvent. After the reaction for 1 h, 0.3 mL of anhydrous N,N-dimethylformamide was added. An orange solid product was obtained (85% yield). 1H NMR (500 MHz, CDCl3), δ (ppm): 10.13 (s, 2H), 8.18 (s, 2H), 4.28 (dd, J = 5.5, 1.8 Hz, 4H), 1.84 (dd, J = 12.2, 6.0 Hz, 2H), 1.71–1.55 (m, 4H), 1.39 (dd, J = 7.5, 3.8 Hz, 12H), 1.02 (t, J = 7.5 Hz, 4H), and 0.97–0.91 (m, 4H) (Figure S3).

2.2.3 2-(4,8-Diethoxybenzo[1,2-b:4,5-b′]dithiophen-2-yl)-1,3-dimethyl-2,3-dihydro-1 H -benzo[ d ]imidazole (BIBDTO)

To a 25 mL microwave reaction flask, N,N′-dimethyl-o-phenylenediamine (136.2 mg,1 mmol) and compound 2 (306.4 mg, 1 mmol) were added. Then, 2 mL of methanol was used as the solvent, and a drop of glacial acetic acid was added to the mixture. After microwave reaction at 60°C for 1 h, the precipitate was filtered and the pale-yellow crystalline product was obtained by recrystallization from acetone (40% yield). 1H NMR (500 MHz, CDCl3), δ (ppm): 7.64 (s, 1H), 7.50 (d, J = 5.4 Hz, 1H), 7.39 (d, J = 5.4 Hz, 1H), 6.83 6.70 (m, 2H), 6.55 6.46 (m, 2H), 5.22 (s, 1H), 4.42 (q, J = 7.0 Hz, 2H), 4.37 (q, J = 7.0 Hz, 2H), 2.74 (s, 6H), 1.54 (t, J = 7.0 Hz, 3H), and 1.48 (t, J = 7.0 Hz, 3H). 13C NMR (125 MHz, CDCl3), δ (ppm): 145.07, 144.53, 144.10, 141.44, 132.47, 131.04, 130.34, 129.99, 126.19, 120.99, 120.49, 119.69, 106.24, 89.72, 69.40, 69.32, 33.44, 16.14,16.08. MS for C23H24N2O2S2: calcd 424.13; and found 424.05 (M+) (Figures S4–S6).

2.2.4 2,2′-(4,8-Bis((2-ethylhexyl)oxy)benzo[1,2- b :4,5- b ′]dithiophene-2,6-diyl)bis(1,3-dimethyl-2,3-dihydro-1 H -benzo[ d ]imidazole) (BBIBDTO)

The synthesis was carried out using the same reaction procedure as that for the preparation of the dopant BIBDTO. Accurately weighted quantities of N,N′-dimethyl-o-phenylenediamine (272.4 mg, 2 mmol) and Compound 4 (502.7 mg, 1 mmol) were taken in a 25 mL microwave reaction flask and 2 mL of methanol was used as solvent with a drop of glacial acetic acid. After the reaction, the crude product was filtered and recrystallized using acetone to obtain a yellow crystalline product (38% yield). 1H NMR (500 MHz, CDCl3), δ (ppm): 7.61 (s, 2H), 6.78 (dd, J = 5.4, 3.2 Hz, 4H), 6.51 (dd, J = 5.4, 3.2 Hz, 4H), 5.21 (s, 2H), 4.23 (dd, J = 5.4, 4.2 Hz, 4H), 2.73 (s, 12H), 1.84–1.78 (m, 2H), 1.72–1.30 (m, 16H), 1.00 (t, J = 7.5 Hz, 6H), and 0.91 (t, J = 7.0 Hz, 6H). 13C NMR (125 MHz, CDCl3), δ (ppm): 145.07, 144.70, 141.49, 131.38, 129.47, 121.12, 119.69, 106.23, 89.81, 75.84, 40.68, 33.41, 30.37, 29.18, 23.83, 23.08, 14.12, 11.32. MS for C44H58N4O2S2: calcd 738.40; found 738.35 (M+) (Figures S7–S9).

3 Results and discussion

3.1 Thermal stability

The effect of the number of benzimidazole functional groups on the thermal stability of benzimidazole-like dopants was investigated using thermogravimetric analysis (TGA) (Figure 3). During the analysis, both dopants were placed in a nitrogen atmosphere to prevent their reaction with H2O and O2 in the air, affecting the reliability of the test results. The analysis was carried out at a temperature ranging from room temperature to 600°C, and the ramp rate was 10°C min−1. The obtained 5% weight loss temperature was 229 and 265°C for BIBDTO and BBIBDTO, respectively. Thus, the results indicate that the use of double benzimidazole functional groups in the design strategy has significantly improved the thermodynamic stability of benzimidazole derivatives containing the same core unit.

Figure 3 TGA curves of BIBDTO and BBIBDTO at a heating rate of 10°C min−1 under nitrogen.
Figure 3

TGA curves of BIBDTO and BBIBDTO at a heating rate of 10°C min−1 under nitrogen.

3.2 Energy level structure

To obtain the energy-level structures of BIBDTO and BBIBDTO, the two dopants were analyzed using UV-vis absorption spectroscopy and cyclic voltammetry (Table 1). As shown in Figure 4, the dopants exhibit an oxidation onset potential E ox onset of 0.14 and 0.09 V for BIBDTO and BBIBDTO, respectively, using the reference electrode Ag/AgNO3 (–4.7 eV for the electrode potential E Ag/AgNO3 relative to vacuum). For BIBDTO, the first oxidation is quasi-reversible, and a minor peak at 0.2 V provides a negative reduction current. Compared with BIBDTO, there is no reduction peak in the voltammogram of BBIBDTO, showing irreversible oxidation characteristics. The HOMO energy levels of BIBDTO and BBIBDTO were calculated following the equation.

(1) E HOMO = E Ag / AgNO3 − E ox onset .

Table 1

The photophysical and electrochemical properties of BIBDTO and BBIBDTO along with their calculated energy levels from DFT

Dopant λ opt onset (nm) E opt g(eV) CV E (V) LUMO (eV) CVHOMO (eV) DFTLUMO (eV) DFTSOMO-1 (eV) DFTSOMO-2 (eV) DFTHOMO (eV)
BIBDTO 369 3.36 0.14 –1.48 –4.84 –1.16 –1.54 N/A –4.72
BBIBDTO 383 3.23 0.09 –1.56 –4.79 −1.35 –1.63 –1.07 –4.53
Figure 4 Cyclic voltammetric curves of (a) BIBDTO and (b) BBIBDTO at a scan rate of 100 mV s−1 at r.t.
Figure 4

Cyclic voltammetric curves of (a) BIBDTO and (b) BBIBDTO at a scan rate of 100 mV s−1 at r.t.

The obtained HOMO energy levels of BIBDTO and BBIBDTO are –4.84 and –4.79 eV, respectively, suggesting easy oxidation characteristics with similar values. The UV-vis absorption spectra of the dopants in dichloromethane solution (concentration of 1 × 10–5 M) are shown in Figure 6. The absorption profile is concentrated in the UV region for the dopants with the starting absorption wavelength λ opt onset of 369 and 383 nm for BIBDTO and BBIBDTO, respectively. Additionally, the optical band gaps were 3.36 and 3.23 eV (E optg = 12.40/λ opt onset) for BIBDTO and BBIBDTO, respectively. The increase in the number of benzimidazole functional groups has resulted in narrowing the bandgap. The LUMO energy levels of BIBDTO and BBIBDTO were obtained as –1.48 and –1.56 eV for BIBDTO and BBIBDTO, respectively, from the following equation.

(2) E LUMO = ( E HOMO + E g ) .

The frontier molecular orbitals of BIBDTO, BBIBDTO, and their imidazoline radicals were calculated using DFT at the (U)B3LYP/6–311++G(d,p) level to reveal the electronic structures of the dopants, especially the SOMO energy levels of their corresponding imidazoline radicals that are difficult to be obtained experimentally (Figure 5). The results show that the HOMO electron cloud distribution of BIBDTO and BBIBDTO is mostly influenced by the benzimidazole functional group. The obtained HOMO energy levels are –4.72 and –4.53 eV for BIBDTO and BBIBDTO, respectively, indicating the presence of the double benzimidazole functional group can increase the HOMO energy level. The LUMO electron cloud distribution of the dopants is primarily affected by the core 2-Ar unit, and the LUMO energy levels were found to be –1.16 and –1.35 eV, respectively, showing a decreasing trend. The calculated HOMO and LUMO energy levels obtained are in good agreement with the experimental results. Furthermore, no spontaneous electron transfer is expected between the dopants and the host material PTEG-2 because the dopants’ HOMO energy levels are lower than the LUMO energy level of PTEG-2 (−4.06 eV; Figure S10) [34]. Typically, the benzimidazole derivatives can produce high-energy imidazoline radicals as a single-electron donor by thermal annealing [21,35]. In this study, the distribution of SOMO electron clouds and their orbital energy levels were obtained using DFT calculations. As the C–H bond at dopant position 2 is broken, producing imidazoline radical, the hybridization state of 2-C changes from sp3 to sp2. The optimized configuration of the imidazoline radical has a planar structure, facilitating the effective conjugation between the core 2-Ar unit and the benzimidazole unit. Therefore, the distribution of the SOMO electron cloud of the two dopant imidazoline radicals can be attributed to the synergistic effect of the core 2-Ar unit and benzimidazole unit. The SOMO energy levels of the BIBDTO single imidazoline radical, BBIBDTO single radical, and BBIBDTO double radical were found to be –1.54, –163, and –1.07 eV, respectively. Among all, the bi-radical exhibits a higher SOMO energy level. As shown in Figure 1, higher SOMO energy levels will provide higher δE ET, facilitating spontaneous electron transfer of the radicals to the host material and eventually forming the corresponding cationic products.

Figure 5 The frontier molecular orbitals of BIBDTO, BBIBDTO, and their imidazoline radicals based on optimized geometries calculated with DFT ((U)B3LYP/6–311++G(d,p)).
Figure 5

The frontier molecular orbitals of BIBDTO, BBIBDTO, and their imidazoline radicals based on optimized geometries calculated with DFT ((U)B3LYP/6–311++G(d,p)).

3.3 Oxidative titration UV-vis absorption spectra

The UV-vis absorption spectra of the dopant cations were measured by adding the oxidant tris (4-bromophenyl) ammonium hexachloroantimonate (TBAH) stepwise to a dichloromethane solution of each benzimidazole derivative (final solution concentration of 1 × 10–5 M). Figure 6a and c show the changes in UV-vis absorption of BIBDTO after dropwise addition of 1 eq. and 2 eq. TBAH, respectively. As can be observed from Figure 6c, the absorption peak gradually enhanced with time after the addition of TBAH, reaching a maximum at 14 min. Further increase in time showed no obvious change in the absorption peak, indicating that BBIBDTO had been completely oxidized at this time. Meanwhile, no visible change was observed even after 30 min in the absorption curve, indicating that the dopant was oxidized to form cations that are stable in the air for a long time. After the oxidation of BIBDTO by 1 eq. TBAH, the UV-vis absorption peak showed the same trend in change as was observed for the time. However, the small change in absorption intensity after 14 min is due to the increase in the concentration of low boiling dichloromethane caused by the volatilization. It can be observed from Figure 6b that the BIBDTO with the mono-benzimidazole functional group gradually increases with the amount of TBAH, and the neutral state absorption peak at 362 nm gradually disappears and is accompanied by a new absorption band between 375 and 480 nm. The new peak can be ascribed to the formation of the C–T complex between the donor and the acceptor. The absorption between 375 and 480 nm is saturated when TBAH reached 1 eq. and showed only a slight enhancement after it. Unlike the mono-benzimidazole functional group BIBDTO, the absorption of the bifunctional BBIBDTO radical cation at 375–480 nm reaches a maximum after the amount of TBAH reaches 2 eq. As a result, the bifunctional dopant molecule can give two electrons at the same time and has a stronger n-doping ability than the monofunctional dopant (Figure 6d).

Figure 6 UV-vis absorption spectra of oxidative titration benzimidazole-based dopants: (a) BIBDTO; (c) BBIBDTO versus time and (b)BIBDTO; (d) BBIBDTI versus oxidant amount.
Figure 6

UV-vis absorption spectra of oxidative titration benzimidazole-based dopants: (a) BIBDTO; (c) BBIBDTO versus time and (b)BIBDTO; (d) BBIBDTI versus oxidant amount.

3.4 Electrical characterization

As discussed in the previous sections, benzimidazole derivatives need to be thermally activated for the formation of a high-energy radical state. Therefore, the optimal temperature for dopant activation was investigated to test the change in conductivity of the doped state films at different doping concentrations. The same core 2-Ar unit structure was used for the mono- and bi-benzimidazole functional group dopants, which can affect the optimum activation temperature. Figure S12 shows the variation curve of conductivity with increasing annealing temperature at the same doping concentration. The doping concentration was 20 mol%, the heating duration used for different annealing temperatures was also maintained at one hour, and the thermal annealing was carried out under nitrogen protection. At a 20 mol% doping concentration, the conductivity of PTEG-2 doped with dopants showed an increasing trend as the annealing temperature increased from 75 to 125°C. This was related to the thermal activation process of the benzimidazole derivatives and the local spatial alignment between the host material and the dopant under thermal stress. As the annealing temperature rises further, the conductivity shows a downward trend due to the different polarities of the solution-mixed dopants and the fullerene derivatives. The optimum annealing temperature for both mono- and bi-benzimidazole functional group dopants was found to be 125°C.

Figure 7 shows the room temperature conductivity curves of doped PTEG-2 films with different doping concentrations after annealing at 125°C for one hour. According to the electrical conductivity equation σ = qnμ (q, carrier charge; n, charge carrier density; and μ, charge carrier mobility), great charge carrier density and efficient carrier transport are essential for high conductivity. The conductivity of the films doped with the two dopants shows an increase followed by a decreasing trend. The increase can be attributed to the added dopants, which introduce extra carriers into the host material. The highest conductivity of 0.29 S cm–1 was obtained at a BIBDTO doping concentration of 15 mol%, while the highest conductivity of 0.15 S cm–1 was obtained at a BBIBDTO doping concentration of 10 mol%. The carrier transport properties of organic semiconductor materials are critically related to the multiscale ordering, including their microscopic stacking and morphology. In many circumstances, it is expected that doping by combining molecular dopants into conjugated semiconductor matrices at a high dopant loading will significantly induce structural disorder [36]. Upon further increase in doping ratio, the decreasing trend in conductivity can be ascribed to the miscibility between the dopant and the host material and damage to the microstructure by the dopant. The BBIBDTO-doped films have the highest conductivity at doping concentrations of less than 7 mol%. This reflects the contribution of the bifunctional dopant to increasing the carrier concentration that dominates at low doping concentrations, as well as the stronger doping ability of BBIBDTO than the monofunctional group BIBDTO. On the other hand, when the doping concentration is further increased, the large volume of bifunctional dopants gradually prevails, destroying the microstructure and is detrimental to the enhancement of conductivity.

Figure 7 The electrical conductivity of doped PTEG-2 films as a function of doping concentration.
Figure 7

The electrical conductivity of doped PTEG-2 films as a function of doping concentration.

4 Conclusion

In this work, we successfully designed and synthesized two benzimidazole dopants, BIBDTO with a mono-benzimidazole functional group and BBIBDTO with bi-benzimidazole functional groups using benzo[1,2-b:4,5-b′]dithiophene as the 2-Ar. The excellent thermal stability and stronger electron-donating ability of BBIBDTO are confirmed by TGA and UV-vis absorption spectra. Further, the electrochemical analysis and theoretical simulations suggested that benzimidazole functional groups primarily influence the HOMO electron cloud distribution of benzimidazoline-based dopants, LUMO is distributed on 2-Ar, and SOMO has both HOMO and LUMO characteristics. The strategy of the bi-benzimidazole functional group can increase the energy level of dopant and imidazoline radicals, favoring n-doping. The conductivity studies implied that the bi-benzimidazole functional group dopants have greater doping capacity at low doping concentrations. At high doping concentrations, the monofunctional BIBDTO is preferable with substantial conductivity. These results can provide guidelines for designing new-generation n-dopants and selecting the type of dopant in different doping systems.

  1. Funding information: This research was funded by the National Key Research and Development Plan (grant No. Q2019YFE-010720).

  2. Author contributions: All data were obtained by authors equally.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Ethical approval: The conducted research is not related to either human or animal use.

  5. Data availability statement: All data generated or analyzed during this study are included in this published article and its supplementary material files.

References

[1] Guan X, Cheng H, Ouyang J. Significant enhancement in the Seebeck coefficient and power factor of thermoelectric polymers by the Soret effect of polyelectrolytes. J Mater Chem A. 2018;6(40):19347–52. 10.1039/C8TA08387H.Search in Google Scholar

[2] Petsagkourakis I, Tybrandt K, Crispin X, Ohkubo I, Satoh N, Mori T. Thermoelectric materials and applications for energy harvesting power generation. Sci Technol Adv Mater. 2018;19(1):836–62. 10.1080/14686996.2018.1530938.Search in Google Scholar PubMed PubMed Central

[3] Root SE, Savagatrup S, Printz AD, Rodriquez D, Lipomi DJ. Mechanical properties of organic semiconductors for stretchable, highly flexible, and mechanically robust electronics. Chem Rev. 2017;117(9):6467–99. 10.1021/acs.chemrev.7b00003.Search in Google Scholar PubMed

[4] Russ B, Glaudell A, Urban JJ, Chabinyc ML, Segalman RA. Organic thermoelectric materials for energy harvesting and temperature control. Nat Rev Mater. 2016;1(10):16050. 10.1038/natrevmats.2016.50.Search in Google Scholar

[5] Fan Z, Du D, Guan X, Ouyang J. Polymer films with ultrahigh thermoelectric properties arising from significant seebeck coefficient enhancement by ion accumulation on surface. Nano Energy. 2018;51:481–8. 10.1016/j.nanoen.2018.07.002.Search in Google Scholar

[6] Schlitz RA, Brunetti FG, Glaudell AM, Miller PL, Brady MA, Takacs CJ, et al. Solubility-limited extrinsic n-type doping of a high electron mobility polymer for thermoelectric applications. Adv Mater. 2014;26(18):2825–30. 10.1002/adma.201304866.Search in Google Scholar PubMed

[7] Lüssem B, Keum CM, Kasemann D, Naab B, Bao Z, Leo K. Doped organic transistors. Chem Rev. 2016;116(22):13714–51. 10.1021/acs.chemrev.6b00329.Search in Google Scholar PubMed

[8] Salzmann I, Heimel G, Oehzelt M, Winkler S, Koch N. Molecular electrical doping of organic semiconductors: Fundamental mechanisms and emerging dopant design rules. Acc Chem Res. 2016;49(3):370–8. 10.1021/acs.accounts.5b00438.Search in Google Scholar PubMed

[9] Walzer K, Maennig B, Pfeiffer M, Leo K. Highly efficient organic devices based on electrically doped transport layers. Chem Rev. 2007;107(4):1233–71. 10.1021/cr050156n.Search in Google Scholar PubMed

[10] Kang K, Watanabe S, Broch K, Sepe A, Brown A, Nasrallah I, et al. 2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion. Nat Mater. 2016;15(8):896–902. 10.1038/nmat4634.Search in Google Scholar PubMed

[11] Kao CY, Lee B, Wielunski LS, Heeney M, McCulloch I, Garfunkel E, et al. Doping of conjugated polythiophenes with alkyl silanes. Adv Funct Mater. 2009;19(12):1906–11. 10.1002/adfm.200900120.Search in Google Scholar

[12] Kiefer D, Kroon R, Hofmann AI, Sun H, Liu X, Giovannitti A, et al. Double doping of conjugated polymers with monomer molecular dopants. Nat Mater. 2019;18(2):149–55. 10.1038/s41563-018-0263-6.Search in Google Scholar PubMed

[13] Liu L, Sun Y, Li W, Zhang J, Huang X, Chen Z, et al. Flexible unipolar thermoelectric devices based on patterned poly[Kx(Ni-ethylenetetrathiolate)] thin films. Mater Chem Front. 2017;1(10):2111–6. 10.1039/C7QM00223H.Search in Google Scholar

[14] Kroon R, Mengistie DA, Kiefer D, Hynynen J, Ryan JD, Yu L, et al. Thermoelectric plastics: from design to synthesis, processing and structure–property relationships. Chem Soc Rev. 2016;45(22):6147–64. 10.1039/C6CS00149A.Search in Google Scholar PubMed PubMed Central

[15] Saglio B, Mura M, Massetti M, Scuratti F, Beretta D, Jiao X, et al. N-Alkyl substituted 1H-benzimidazoles as improved n-type dopants for a naphthalene-diimide based copolymer. J Mater Chem A. 2018;6(31):15294–302. 10.1039/C8TA04901G.Search in Google Scholar

[16] Yang CY, Ding YF, Huang D, Wang J, Yao ZF, Huang CX, et al. A thermally activated and highly miscible dopant for n-type organic thermoelectrics. Nat Commun. 2020;11(1):1–10. 10.1038/s41467-020-17063-1.Search in Google Scholar PubMed PubMed Central

[17] Barbot A, Lucas B, Di Bin C, Ratier B. Cesium carbonate-doped 1,4,5,8-naphthalene-tetracarboxylic-dianhydride used as efficient electron transport material in polymer solar cells. Org Electron. 2014;15(4):858–63. 10.1016/j.orgel.2014.02.001.Search in Google Scholar

[18] Kao PC, Wang JY, Lin JH, Yang CH. Effects of the Na2CO3 dopant on electron injection and transport in organic light emitting devices. Thin Solid Films. 2013;527:338–43. 10.1016/j.tsf.2012.11.038.Search in Google Scholar

[19] Parthasarathy G, Shen C, Kahn A, Forrest SR. Lithium doping of semiconducting organic charge transport materials. J Appl Phys. 2001;89(9):4986–92. 10.1063/1.1359161.Search in Google Scholar

[20] Goetz KP, Vermeulen D, Payne ME, Kloc C, McNeil LE, Jurchescu OD. Charge-transfer complexes: new perspectives on an old class of compounds. J Mater Chem C. 2014;2(17):3065–76. 10.1039/C3TC32062F.Search in Google Scholar

[21] Wei P, Oh JH, Dong G, Bao Z. Use of a 1H-benzoimidazole derivative as an n-type dopant and to enable air-stable solution-processed n-channel organic thin-film transistors. J Am Chem Soc. 2010;132(26):8852–3. 10.1021/ja103173m.Search in Google Scholar PubMed

[22] Lu Y, Yu ZD, Zhang RZ, Yao ZF, You HY, Jiang L, et al. Rigid coplanar polymers for stable n-type polymer thermoelectrics. Angew Chem Int Ed. 2019;58(33):11390–4. 10.1002/anie.201905835.Search in Google Scholar PubMed

[23] Naab BD, Guo S, Olthof S, Evans EG, Wei P, Millhauser GL, et al. Mechanistic study on the solution-phase n-doping of 1,3-Dimethyl-2-aryl-2,3-dihydro-1H-benzoimidazole derivatives. J Am Chem Soc. 2013;135:15018. 10.1039/C3TC32062F.Search in Google Scholar

[24] Riera-Galindo S, Orbelli Biroli A, Forni A, Puttisong Y, Tessore F, Pizzotti M, et al. Impact of singly occupied molecular orbital energy on the n-doping efficiency of benzimidazole derivatives. ACS Appl Mater Interfaces. 2019;11(41):37981–90. 10.1021/acsami.9b12441.Search in Google Scholar PubMed

[25] Yang CY, Jin WL, Wang J, Ding YF, Nong SY, Shi K, et al. Enhancing the n-type conductivity and thermoelectric performance of donor–acceptor copolymers through donor engineering. Adv Mater. 2018;30(43):1802850. 10.1002/adma.201802850.Search in Google Scholar PubMed

[26] Liu J, Qiu L, Portale G, Koopmans M, ten Brink G, Hummelen JC, et al. N-type organic thermoelectrics: Improved power factor by tailoring host–dopant miscibility. Adv Mater. 2017;29(36):1701641. 10.1002/adma.201701641.Search in Google Scholar PubMed

[27] Liu J, Qiu L, Portale G, Torabi S, Stuart MCA, Qiu X, et al. Side-chain effects on N-type organic thermoelectrics: A case study of fullerene derivatives. Nano Energy. 2018;52:183–91. 10.1016/j.nanoen.2018.07.056.Search in Google Scholar

[28] Liu J, Zee B, Alessandri R, Sami S, Dong J, Nugraha MI, et al. N-type organic thermoelectrics: demonstration of ZT  >  0.3. Nat Commun. 2020;11(1):1–9. 10.1038/s41467-020-19537-8.Search in Google Scholar PubMed PubMed Central

[29] Igarashi T, Tayama E, Iwamoto H, Hasegawa E. Carbon–carbon bond formation via benzoyl umpolung attained by photoinduced electron-transfer with benzimidazolines. Tetrahedron Lett. 2013;54(50):6874–7. 10.1016/j.tetlet.2013.10.028.Search in Google Scholar

[30] Ou Y, Tang S, Wang A, Li J, Zhang F, Xu Z. Binuclear ruthenium complexes with Benzo[1,2-b;4,5-b′]dithiophene analogues as bridge ligands: Syntheses, characterization and notable difference on electronic coupling. Chin J Chem. 2017;35(7):1170–8. 10.1002/cjoc.201700220.Search in Google Scholar

[31] Devisscher D, Reekmans G, Kesters J, Verstappen P, Benduhn J, Van den Brande N, et al. Analysis of bulk heterojunction organic solar cell blends by solid-state NMR relaxometry and sensitive external quantum efficiency – Impact of polymer side chain variation on nanoscale morphology. Org Electron. 2019;74:309–14. 10.1016/j.orgel.2019.06.046.Search in Google Scholar

[32] Jahani F, Torabi S, Chiechi RC, Koster LJA, Hummelen JC. Fullerene derivatives with increased dielectric constants. Chem Commun. 2014;50(73):10645–7. 10.1039/C4CC04366A.Search in Google Scholar PubMed

[33] Frisch M, Trucks G, Schlegel H, Scuseria G, Robb M, Cheeseman J, et al. Gaussian 16 Revision D. 01. Wallingford CT: USA; 2009.Search in Google Scholar

[34] Yuan D, Huang D, Zhang C, Zou Y, Di C-A, Zhu X, et al. Efficient solution-processed n-type small-molecule thermoelectric materials achieved by precisely regulating energy level of organic dopants. ACS Appl Mater Interfaces. 2017;9(34):28795–801. 10.1021/acsami.7b07282.Search in Google Scholar PubMed

[35] Huang D, Yao H, Cui Y, Zou Y, Zhang F, Wang C, et al. Conjugated-backbone effect of organic small molecules for n-type thermoelectric materials with ZT over 0.2. J Am Chem Soc. 2017;139(37):13013–23. 10.1021/jacs.7b05344.Search in Google Scholar PubMed

[36] Duong DT, Wang C, Antono E, Toney MF, Salleo A. The chemical and structural origin of efficient P-type doping in P3HT. Org Electron. 2013;14(5):1330–6. 10.1016/j.orgel.2013.02.028.Search in Google Scholar
Received: 2022-07-02
Revised: 2022-07-31
Accepted: 2022-08-12
Published Online: 2022-09-07

© 2022 Chenqing Tang and Gongchun Li, published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

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  4. A detailed investigation on highly dense CuZr bulk metallic glasses for shielding purposes
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  6. Environmental impact assesment regulation applications and their analysis in Turkey
  7. Sample age effect on parameters of dynamic nuclear polarization in certain difluorobenzen isomers/MC800 asphaltene suspensions
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  9. Design of a Robust sliding mode controller for bioreactor cultures in overflow metabolism via an interdisciplinary approach
  10. Gamma, neutron, and heavy charged ion shielding properties of Er3+-doped and Sm3+-doped zinc borate glasses
  11. Bridging chiral de-tert-butylcalix[4]arenes: Optical resolution based on column chromatography and structural characterization
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https://doi.org/10.1515/chem-2022-0202
Keywords for this article
n-dopants; molecular engineering; energy level structure; conductivity
Creative Commons
BY 4.0

Articles in the same Issue

  1. Regular Articles
  2. Photocatalytic degradation of Rhodamine B in aqueous phase by bimetallic metal-organic framework M/Fe-MOF (M = Co, Cu, and Mg)
  3. Assessment of using electronic portal imaging device for analysing bolus material utilised in radiation therapy
  4. A detailed investigation on highly dense CuZr bulk metallic glasses for shielding purposes
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  6. Environmental impact assesment regulation applications and their analysis in Turkey
  7. Sample age effect on parameters of dynamic nuclear polarization in certain difluorobenzen isomers/MC800 asphaltene suspensions
  8. Passenger demand forecasting for railway systems
  9. Design of a Robust sliding mode controller for bioreactor cultures in overflow metabolism via an interdisciplinary approach
  10. Gamma, neutron, and heavy charged ion shielding properties of Er3+-doped and Sm3+-doped zinc borate glasses
  11. Bridging chiral de-tert-butylcalix[4]arenes: Optical resolution based on column chromatography and structural characterization
  12. Petrology and geochemistry of multiphase post-granitic dikes: A case study from the Gabal Serbal area, Southwestern Sinai, Egypt
  13. Comparison of the yield and purity of plasma exosomes extracted by ultracentrifugation, precipitation, and membrane-based approaches
  14. Bioactive triterpenoids from Indonesian medicinal plant Syzygium aqueum
  15. Investigation of the effects of machining parameters on surface integrity in micromachining
  16. The mesoporous aluminosilicate application as support for bifunctional catalysts for n-hexadecane hydroconversion
  17. Gamma-ray shielding properties of Nd2O3-added iron–boron–phosphate-based composites
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  19. Statistical analysis on the radiological assessment and geochemical studies of granite rocks in the north of Um Taghir area, Eastern Desert, Egypt
  20. Two new polypodane-type bicyclic triterpenoids from mastic
  21. Structural, physical, and mechanical properties of the TiO2 added hydroxyapatite composites
  22. Tribological properties and characterization of borided Co–Mg alloys
  23. Studies on Anemone nemorosa L. extracts; polyphenols profile, antioxidant activity, and effects on Caco-2 cells by in vitro and in silico studies
  24. Mechanical properties, elastic moduli, transmission factors, and gamma-ray-shielding performances of Bi2O3–P2O5–B2O3–V2O5 quaternary glass system
  25. Cyclic connectivity index of bipolar fuzzy incidence graph
  26. The role of passage numbers of donor cells in the development of Arabian Oryx – Cow interspecific somatic cell nuclear transfer embryos
  27. Mechanical property evaluation of tellurite–germanate glasses and comparison of their radiation-shielding characteristics using EPICS2017 to other glass systems
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  30. Iminodisuccinic acid enhances antioxidant and mineral element accumulation in young leaves of Ziziphus jujuba
  31. Cytotoxic activity of guaiane-type sesquiterpene lactone (deoxycynaropicrin) isolated from the leaves of Centaurothamnus maximus
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  34. Effect of different ramie (Boehmeria nivea L. Gaud) cultivars on the adsorption of heavy metal ions cadmium and lead in the remediation of contaminated farmland soils
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  45. Texturing of nanocoatings for surface acoustic wave-based sensors for volatile organic compounds
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  57. The potential effect of the Rumex vesicarius water seeds extract treatment on mice before and during pregnancy on the serum enzymes and the histology of kidney and liver
  58. Impact of benzimidazole functional groups on the n-doping properties of benzimidazole derivatives
  59. Extraction of red pigment from Chinese jujube peel and the antioxidant activity of the pigment extracts
  60. Flexural strength and thermal properties of carbon black nanoparticle reinforced epoxy composites obtained from waste tires
  61. A focusing study on radioprotective and antioxidant effects of Annona muricata leaf extract in the circulation and liver tissue: Clinical and experimental studies
  62. Clinical comprehensive and experimental assessment of the radioprotective effect of Annona muricata leaf extract to prevent cellular damage in the ileum tissue
  63. Effect of WC content on ultrasonic properties, thermal and electrical conductivity of WC–Co–Ni–Cr composites
  64. Influence of various class cleaning agents for prosthesis on Co–Cr alloy surface
  65. The synthesis of nanocellulose-based nanocomposites for the effective removal of hexavalent chromium ions from aqueous solution
  66. Study on the influence of physical interlayers on the remaining oil production under different development modes
  67. Optimized linear regression control of DC motor under various disturbances
  68. Influence of different sample preparation strategies on hypothesis-driven shotgun proteomic analysis of human saliva
  69. Determination of flow distance of the fluid metal due to fluidity in ductile iron casting by artificial neural networks approach
  70. Investigation of mechanical activation effect on high-volume natural pozzolanic cements
  71. In vitro: Anti-coccidia activity of Calotropis procera leaf extract on Eimeria papillata oocysts sporulation and sporozoite
  72. Determination of oil composition of cowpea (Vigna unguiculata L.) seeds under influence of organic fertilizer forms
  73. Activated partial thromboplastin time maybe associated with the prognosis of papillary thyroid carcinoma
  74. Treatment of rat brain ischemia model by NSCs-polymer scaffold transplantation
  75. Lead and cadmium removal with native yeast from coastal wetlands
  76. Characterization of electroless Ni-coated Fe–Co composite using powder metallurgy
  77. Ferrate synthesis using NaOCl and its application for dye removal
  78. Antioxidant, antidiabetic, and anticholinesterase potential of Chenopodium murale L. extracts using in vitro and in vivo approaches
  79. Study on essential oil, antioxidant activity, anti-human prostate cancer effects, and induction of apoptosis by Equisetum arvense
  80. Experimental study on turning machine with permanent magnetic cutting tool
  81. Numerical simulation and mathematical modeling of the casting process for pearlitic spheroidal graphite cast iron
  82. Design, synthesis, and cytotoxicity evaluation of novel thiophene, pyrimidine, pyridazine, and pyridine: Griseofulvin heterocyclic extension derivatives
  83. Isolation and identification of promising antibiotic-producing bacteria
  84. Ultrasonic-induced reversible blood–brain barrier opening: Safety evaluation into the cellular level
  85. Evaluation of phytochemical and antioxidant potential of various extracts from traditionally used medicinal plants of Pakistan
  86. Effect of calcium lactate in standard diet on selected markers of oxidative stress and inflammation in ovariectomized rats
  87. Identification of crucial salivary proteins/genes and pathways involved in pathogenesis of temporomandibular disorders
  88. Zirconium-modified attapulgite was used for removing of Cr(vi) in aqueous solution
  89. The stress distribution of different types of restorative materials in primary molar
  90. Reducing surface heat loss in steam boilers
  91. Deformation behavior and formability of friction stir processed DP600 steel
  92. Synthesis and characterization of bismuth oxide/commercial activated carbon composite for battery anode
  93. Phytochemical analysis of Ziziphus jujube leaf at different foliar ages based on widely targeted metabolomics
  94. Effects of in ovo injection of black cumin (Nigella sativa) extract on hatching performance of broiler eggs
  95. Separation and evaluation of potential antioxidant, analgesic, and anti-inflammatory activities of limonene-rich essential oils from Citrus sinensis (L.)
  96. Bioactivity of a polyhydroxy gorgostane steroid from Xenia umbellata
  97. BiCAM-based automated scoring system for digital logic circuit diagrams
  98. Analysis of standard systems with solar monitoring systems
  99. Structural and spectroscopic properties of voriconazole and fluconazole – Experimental and theoretical studies
  100. New plant resistance inducers based on polyamines
  101. Experimental investigation of single-lap bolted and bolted/bonded (hybrid) joints of polymeric plates
  102. Investigation of inlet air pressure and evaporative cooling of four different cogeneration cycles
  103. Review Articles
  104. Comprehensive review on synthesis, physicochemical properties, and application of activated carbon from the Arecaceae plants for enhanced wastewater treatment
  105. Research progress on speciation analysis of arsenic in traditional Chinese medicine
  106. Recent modified air-assisted liquid–liquid microextraction applications for medicines and organic compounds in various samples: A review
  107. An insight on Vietnamese bio-waste materials as activated carbon precursors for multiple applications in environmental protection
  108. Antimicrobial activities of the extracts and secondary metabolites from Clausena genus – A review
  109. Bioremediation of organic/heavy metal contaminants by mixed cultures of microorganisms: A review
  110. Sonodynamic therapy for breast cancer: A literature review
  111. Recent progress of amino acid transporters as a novel antitumor target
  112. Aconitum coreanum Rapaics: Botany, traditional uses, phytochemistry, pharmacology, and toxicology
  113. Corrigendum
  114. Corrigendum to “Petrology and geochemistry of multiphase post-granitic dikes: A case study from the Gabal Serbal area, Southwestern Sinai, Egypt”
  115. Corrigendum to “Design of a Robust sliding mode controller for bioreactor cultures in overflow metabolism via an interdisciplinary approach”
  116. Corrigendum to “Statistical analysis on the radiological assessment and geochemical studies of granite rocks in the north of Um Taghir area, Eastern Desert, Egypt”
  117. Corrigendum to “Aroma components of tobacco powder from different producing areas based on gas chromatography ion mobility spectrometry”
  118. Corrigendum to “Mechanical properties, elastic moduli, transmission factors, and gamma-ray-shielding performances of Bi2O3–P2O5–B2O3–V2O5 quaternary glass system”
  119. Erratum
  120. Erratum to “Copper(ii) complexes supported by modified azo-based ligands: Nucleic acid binding and molecular docking studies”
  121. Special Issue on Applied Biochemistry and Biotechnology (ABB 2021)
  122. Study of solidification and stabilization of heavy metals by passivators in heavy metal-contaminated soil
  123. Human health risk assessment and distribution of VOCs in a chemical site, Weinan, China
  124. Preparation and characterization of Sparassis latifolia β-glucan microcapsules
  125. Special Issue on the Conference of Energy, Fuels, Environment 2020
  126. Improving the thermal performance of existing buildings in light of the requirements of the EU directive 2010/31/EU in Poland
  127. Special Issue on Ethnobotanical, Phytochemical and Biological Investigation of Medicinal Plants
  128. Study of plant resources with ethnomedicinal relevance from district Bagh, Azad Jammu and Kashmir, Pakistan
  129. Studies on the chemical composition of plants used in traditional medicine in Congo
  130. Special Issue on Applied Chemistry in Agriculture and Food Science
  131. Strip spraying technology for precise herbicide application in carrot fields
  132. Special Issue on Pharmacology and Metabolomics of Ethnobotanical and Herbal Medicine
  133. Phytochemical profiling, antibacterial and antioxidant properties of Crocus sativus flower: A comparison between tepals and stigmas
  134. Antioxidant and antimicrobial properties of polyphenolics from Withania adpressa (Coss.) Batt. against selected drug-resistant bacterial strains
  135. Integrating network pharmacology and molecular docking to explore the potential mechanism of Xinguan No. 3 in the treatment of COVID-19
  136. Chemical composition and in vitro and in vivo biological assortment of fixed oil extracted from Ficus benghalensis L.
  137. A review of the pharmacological activities and protective effects of Inonotus obliquus triterpenoids in kidney diseases
  138. Ethnopharmacological study of medicinal plants in Kastamonu province (Türkiye)
  139. Protective effects of asperuloside against cyclophosphamide-induced urotoxicity and hematotoxicity in rats
  140. Special Issue on Essential Oil, Extraction, Phytochemistry, Advances, and Application
  141. Identification of volatile compounds and antioxidant, antibacterial, and antifungal properties against drug-resistant microbes of essential oils from the leaves of Mentha rotundifolia var. apodysa Briq. (Lamiaceae)
  142. Phenolic contents, anticancer, antioxidant, and antimicrobial capacities of MeOH extract from the aerial parts of Trema orientalis plant
  143. Chemical composition and antimicrobial activity of essential oils from Mentha pulegium and Rosmarinus officinalis against multidrug-resistant microbes and their acute toxicity study
  144. Special Issue on Marine Environmental Sciences and Significance of the Multidisciplinary Approaches
  145. An insightful overview of the distribution pattern of polycyclic aromatic hydrocarbon in the marine sediments of the Red Sea
  146. Antifungal–antiproliferative norcycloartane-type triterpenes from the Red Sea green alga Tydemania expeditionis
  147. Solvent effect, dipole moment, and DFT studies of multi donor–acceptor type pyridine derivative
  148. An extensive assessment on the distribution pattern of organic contaminants in the aerosols samples in the Middle East
  149. Special Issue on 4th IC3PE
  150. Energetics of carboxylic acid–pyridine heterosynthon revisited: A computational study of intermolecular hydrogen bond domination on phenylacetic acid–nicotinamide cocrystals
  151. A review: Silver–zinc oxide nanoparticles – organoclay-reinforced chitosan bionanocomposites for food packaging
  152. Green synthesis of magnetic activated carbon from peanut shells functionalized with TiO2 photocatalyst for Batik liquid waste treatment
  153. Coagulation activity of liquid extraction of Leucaena leucocephala and Sesbania grandiflora on the removal of turbidity
  154. Hydrocracking optimization of palm oil over NiMoO4/activated carbon catalyst to produce biogasoline and kerosine
  155. Special Issue on Pharmacology and metabolomics of ethnobotanical and herbal medicine
  156. Cynarin inhibits PDGF-BB-induced proliferation and activation in hepatic stellate cells through PPARγ
  157. Special Issue on The 1st Malaysia International Conference on Nanotechnology & Catalysis (MICNC2021)
  158. Surfactant evaluation for enhanced oil recovery: Phase behavior and interfacial tension
  159. Topical Issue on phytochemicals, biological and toxicological analysis of aromatic medicinal plants
  160. Phytochemical analysis of leaves and stems of Physalis alkekengi L. (Solanaceae)
  161. Phytochemical and pharmacological profiling of Trewia nudiflora Linn. leaf extract deciphers therapeutic potentials against thrombosis, arthritis, helminths, and insects
  162. Pergularia tomentosa coupled with selenium nanoparticles salvaged lead acetate-induced redox imbalance, inflammation, apoptosis, and disruption of neurotransmission in rats’ brain
  163. Protective effect of Allium atroviolaceum-synthesized SeNPs on aluminum-induced brain damage in mice
  164. Mechanism study of Cordyceps sinensis alleviates renal ischemia–reperfusion injury
  165. Plant-derived bisbenzylisoquinoline alkaloid tetrandrine prevents human podocyte injury by regulating the miR-150-5p/NPHS1 axis
  166. Network pharmacology combined with molecular docking to explore the anti-osteoporosis mechanisms of β-ecdysone derived from medicinal plants
  167. Chinese medicinal plant Polygonum cuspidatum ameliorates silicosis via suppressing the Wnt/β-catenin pathway
  168. Special Issue on Advanced Nanomaterials for Energy, Environmental and Biological Applications - Part I
  169. Investigation of improved optical and conductivity properties of poly(methyl methacrylate)–MXenes (PMMA–MXenes) nanocomposite thin films for optoelectronic applications
  170. Special Issue on Applied Biochemistry and Biotechnology (ABB 2022)
  171. Model predictive control for precision irrigation of a Quinoa crop
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