Co-sensitization of the HD-2 complex with low-cost cyanoacetanilides for highly efficient DSSCs.

The photophysical and electrochemical properties of new targeted 2-cyanoacetanilide-based dyes are illustrated. New cyanoacetanilides SA7-10 were synthesized and employed as co-sensitizers in DSSCs. The chemical structures of these 2-cyanoacetanilides differ according to the substituent at the benzene ring (-H, -Me, -OMe and -NEt2), with the anchoring moiety being the same, a -COOH group. Furthermore, a density functional theory (DFT) calculation has shown an effective intermolecular charge transfer character, the HOMOs of SA7-10 are mainly located on the corresponding donor part, and their LUMOs are located on carboxylic acid moieties as the acceptor. Interestingly, using photosensitizers SA7-10 as co-sensitizers with HD-2 dye causes an improvement in their photovoltaic performances. Among the dyes, SA10 co-sensitized with HD-2 displayed an overall efficiency of 8.25%, a JSC of 19.5 mA cm-2, a VOC of 0.65 V and an FF of 64.35 compared to 7.46%, 19 mA cm-2, 0.64 V and 60.54, respectively, of HD-2 only. Moreover, the electrochemical impedance spectroscopy (EIS) data of SA7-10 and HD-2 were found to be in accordance with the obtained photovoltaic parameters. Finally, the results indicated that 2-cyanoacetanilide-based dyes were utilized as promising co-sensitizers due to their easy preparation methods and their relatively small size.

New di-anchoring A-π-D-π-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies.

Herein, we report the design and synthesis of three new un-symmetrical metal-free carbazole based organic dyes, E1-3 with A-π-D-π-A architecture, as effective di-anchoring sensitizers in DSSCs. The new entities comprise carbazole as a donor scaffold connected to three different units, viz. cyano acetic acid, 2,4-thiazolidinedione and barbituric acid as acceptor/anchoring units via vinylene and phenylene as π-spacers at 3- and 6-positions of the carbazole ring, respectively. Photophysical, electrochemical and theoretical studies were carried out in order to assess their feasibility as active sensitizers. Furthermore, their photoelectrochemical performances and charge transport properties in fabricated DSSCs were evaluated. The results revealed that the device fabricated with the E1 sensitizer displayed the highest PCE of 2.38% among the three dyes. Its JSC, VOC, and IPCE values were found to be 6.36 mA cm-2, 0.599 V, and 57%, respectively. Its enhanced performance is attributed to the presence of a highly electron withdrawing cyano acetic acid unit on either side of the carbazole core through appropriate π-spacers. Interestingly, the DFT study indicated that the electron cloud of the LUMO level has been shifted significantly towards the 2-cyano phenyl acrylic acid connected at the 6th position of the carbazole ring, when compared to the cyano acrylic acid linked at position 3, confirming efficient charge separation in E1. The assigned lifetimes of E1-3 obtained from EIS studies were found to be in accordance with experimentally obtained photovoltaic parameters. Furthermore, E1-3, when co-sensitized with NCSU-10 sensitizer in DSSCs, displayed higher VOC values, but lower PCE values than that of NCSU-10.

Correction: New di-anchoring A-π-D-π-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies.

Correction for 'New di-anchoring A-π-D-π-A configured organic chromophores for DSSC application: sensitization and co-sensitization studies' by Praveen Naik et al., Photochem. Photobiol. Sci., 2018, DOI: 10.1039/c7pp00351j.

Unleashing synergistic co-sensitization of BOA dyes and Ru(ii) complexes for dye-sensitized solar cells: achieving remarkable efficiency exceeding 10% through comprehensive characterization, advanced modeling, and performance analysis.

Dye-sensitized solar cells (DSSCs) have emerged as a promising alternative for renewable energy conversion. The synthesis and characterization of the 2-acetonitrile-benzoxazole (BOA) sensitizer MSW-1-4 are presented along with their chemical structures. Four new organic dyes, MSW-1 through MSW-4, were synthesized using BOA as the main building block, with different additional donor groups. The dyes were characterized and their photophysical and electrochemical properties were studied. Computational modeling using density functional theory (DFT) was performed to investigate their potential as sensitizers/co-sensitizers for photovoltaic applications. The modeling showed a distinct charge separation between the donor and acceptor parts of the molecules. For dye-sensitized solar cells, MSW-4 performed the best out of MSW-1-3 and was also better than the reference dye D-5. Moreover, MSW-3 was co-sensitized along with a typical highly efficient bipyridyl Ru(ii) sensitizer, N719, reference dye D-5, and metal-free dye MSW-4, to induce light harvesting over the expanded spectral region and hence improve the efficiency. Co-sensitizer (MSW-3 + N719) showed an improved efficiency of 10.20%. This outperformed a solar cell that used only N719 as the sensitizer, which had an efficiency of 7.50%. The appropriate combined dye loading of MSW-3 + N719 enabled good light harvesting and maximized the photoexcitation. The synergistic effect of using both MSW-3 and N719 as co-sensitizers led to enhanced solar cell performance compared with using N719 alone.

Anticancer evaluation and molecular docking of new pyridopyrazolo-triazine and pyridopyrazolo-triazole derivatives.

3-Amino-4,6-dimethylpyrazolopyridine was applied as a precursor for the synthesis of some new pyridopyrazolo-triazine and pyridopyrazolo-triazole derivatives through diazotization, followed by coupling with many 2-cyanoacetamide compounds, ethyl 3-(phenylamino)-3-thioxopropanoate, 3-oxo-N-phenylbutanethioamide, and α-bromo-ketone reagents [namely; 2-bromo-1-(4-fluorophenyl)ethan-1-one, 5-bromo-2-(bromoacetyl)thiophene, 3-(2-bromoacetyl)-2H-chromen-2-one and/or 3-chloroacetylacetone]. The prepared compounds were identified by spectroscopic analyses as IR, 1H NMR, and mass data. The anticancer activity of these pyrazolopyridine analogues was investigated in colon, hepatocellular, breast, and cervix carcinoma cell lines. The pyridopyrazolo-triazine compound 5a substituted with a carboxylate group gave a distinguished value of IC50 = 3.89 µM against the MCF-7 cell line compared to doxorubicin as a reference drug. Also, the pyridopyrazolo-triazine compound 6a substituted with the carbothioamide function gave good activity toward HCT-116 and MCF-7 cell lines with IC50 values of 12.58 and 11.71 µM, respectively. The discovered pyrazolopyridine derivatives were studied theoretically by molecular docking, and this study exhibited suitable binding between the active sides of pyrazolopyridine ligands and proteins (PDB ID: 5IVE). The pyridopyrazolo-triazine compound 6a showed the highest free binding energy (- 7.8182 kcal/mol) when docked inside the active site of selected proteins.

Design, synthesis, and performance evaluation of TiO2-dye sensitized solar cells using 2,2'-bithiophene-based co-sensitizers.

We report on the synthesis and characterization of six novel 2,2'-bithiophene-based organic compounds (3a-c and 5a-c) that are designed to serve as co-sensitizers for dye-sensitized solar cells (DSSCs) based on TiO2. The compounds are linked to various donor and acceptor groups, and we confirm their chemical structures through spectral analyses. Our focus is on enhancing the performance of metal based N3, and the compounds were designed to operate at the nanoscale. We performed absorption and fluorescence emission measurements in dimethylformamide (DMF), where one of our compounds 5a exhibited the longest maximum absorption and maximum emission wavelengths, indicating the significant impact of the para methoxy group as a strong electron-donating group. Our dyes 5a + N3 (η = 7.42%) and 5c + N3 (η = 6.57%) outperformed N3 (η = 6.16%) alone, where the values of short current density (JSC) and open circuit voltage (VOC) for these two systems also improved. We also investigated the charge transfer resistance at the TiO2/dye/electrolyte interface using electrochemical impedance spectroscopy (EIS), which is important in the context of nanotechnology. According to the Nyquist plot, the 5a + N3 cocktail exhibited the lowest recombination rate, resulting in the highest VOC. Our theoretical calculations based on density functional theory (DFT) are also in agreement with the experimental process. These findings suggest that our compounds have great potential as efficient DSSC co-sensitizers. This study provides valuable insights into the design and synthesis of new organic compounds for use as co-sensitizers in DSSCs based on TiO2 and highlights the potential of these compounds for use in efficient solar energy conversion.

Synthesis of efficient bi-anchoring bifuran/biphenyl derivatives for dye-sensitized solar cell applications.

The synthesis, description, and demonstration of dye-sensitive solar cell sensitizers containing bifuran/biphenyl derivatives with cyanoacetic acid, barbiturate, thiobarbituric acid, and 4-carboxylcyanoacetamides have been reported. A photovoltaic performance measurement was conducted using the Ru(ii) dye N3 as a reference to examine the effects of different electron acceptor units and replacement of the π-spacer bifuran by biphenyl units on the photophysical, electrochemical, and photovoltaic properties of eight new distinct organic dyes HB-1-8. The new organic dyes HB-1-8 were prepared and compared with the N3 metal dye. Density functional theory calculations were carried out to explore the ground state geometrical structures and electronic structures of the eight dyes. Under standard global AM 1.5 solar condition, the solar cells based on HB-1-8 show the overall power conversion efficiencies of 2.93-5.51%. The presented research shows that the organic dye photovoltaic performances can vary greatly depending on the type of electron donor and acceptor used. Dye HB-3 exhibited the highest efficiency among the eight investigated dyes, reaching 5.51% with a V OC value higher than N3.

Synthesis, biological evaluation and molecular docking of new triphenylamine-linked pyridine, thiazole and pyrazole analogues as anticancer agents.

A new series of pyridine, thiazole, and pyrazole analogues were synthesized. The pyridone analogues 4a-e were synthesized by treating N-aryl-2-cyano-3-(4-(diphenylamino)phenyl)acrylamides 3a-e with malononitrile. Many 4-arylidene-thiazolidin-5-one analogues 6a-d were obtained by Knoevenagel reactions of 4-(diphenylamino)benzaldehyde (1) with their corresponding thiazolidin-5-one derivatives 5a-d. The structural elucidation of the products was proven by the collections of spectroscopic methods such as IR, 1H NMR, 13C NMR, and MS data. Their anti-cancer activity was examined against two cell lines, MDA-MB-231 (mammary carcinomas) and A-549 (lung cancer). Compared with cisplatin as a reference standard drug, 6-amino-4-(4-(diphenylamino)phenyl)-2-oxo-1-(p-tolyl)-1,2-dihydropyridine-3,5-dicarbonitrile (4b) and 6-amino-4-(4-(diphenylamino)phenyl)-1-(4-nitrophenyl)-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile (4e) exhibited better efficiency against the A-549 cell line, with IC50 = 0.00803 and 0.0095 µM, respectively. Also, these compounds 4b and 4e showed the most potency among the examined compounds against MDA-MB-231 with IC50 = 0.0103 and 0.0147 µM, respectively. The newly synthesized compounds were docked inside the active sites of the selected proteins and were found to demonstrate proper binding. 2-Cyano-2-(4,4-(diphenylamino)benzylidene)-5-oxo-3-phenylthiazolidin-2-ylidene)-N-(p-tolyl)acetamide (6c) offered the highest binding affinity (- 8.1868 kcal/mol) when docked into (PDB ID:2ITO), in addition to 2-cyano-N-(4-(diethylamino)phenyl)-2-(4-(4-(diphenylamino)benzylidene)-5-oxo-3-phenylthiazolidin-2-ylidene)acetamide (6a) gave the highest energy score (- 9.3507 kcal/mol) with (PDB ID:2A4L).

Synthesis of Novel Triphenylamine-Based Organic Dyes with Dual Anchors for Efficient Dye-Sensitized Solar Cells.

A new series of metal-free organic dyes (SM1-5) with dual anchors are synthesized for application in dye-sensitized solar cells (DSSC). Here, a simple triphenylamine (TPA) moiety serves as the electron donor, while di-cyanoacrylamide and di-thiazolidine-5-one units serve as the electron acceptors and anchoring groups. To understand the effect of dye structure on the photovoltaic characteristics of DSSCs, the photophysical and electrochemical properties, as well as molecular geometries calculated from density functional theory (DFT), are used for dyes SM1-5. The extinction coefficients of the organic dyes SM1-5 are high (5.36-9.54 104 M-1 cm-1), indicating a high aptitude for light harvesting. The photovoltaic studies indicated that using dye SM4 as a sensitizer showed a power conversion efficiency (PCE) of 6.09% (JSC = 14.13 mA cm-2, VOC = 0.624 V, FF = 68.89%). Interestingly, SM4 showed the highest values of VOC among all dyes, including N-719, due to its maximum dye coverage on the TiO2 surface, enhancing charge recombination resistance in the sensitized cell. The good agreement between the theoretically and experimentally obtained data indicates that the energy functional and basis set employed in this study can be successfully utilized to predict new photosensitizers' absorption spectra with great precision before synthesis. Also, these results show that bi-anchoring molecules have a lot of potentials to improve the overall performance of dye-sensitized solar cells.

Synthesis of innovative triphenylamine-functionalized organic photosensitizers outperformed the benchmark dye N719 for high-efficiency dye-sensitized solar cells.

Herein, we present a thorough photovoltaic investigation of four triphenylamine organic sensitizers with D-π-A configurations and compare their photovoltaic performances to the conventional ruthenium-based sensitizer N719. SFA-5-8 are synthesized and utilized as sensitizers for dye-sensitized solar cell (DSSC) applications. The effects of the donor unit (triphenylamine), π-conjugation bridge (thiophene ring), and various acceptors (phenylacetonitrile and 2-cyanoacetamide derivatives) were investigated. Moreover, this was asserted by profound calculations of HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, the molecular electrostatic potential (MEP), and natural bond orbital (NBO) that had been studied for the TPA-sensitizers. Theoretical density functional theory (DFT) was performed to study the distribution of electron density between donor and acceptor moieties. The sensitization by the absorption of sensitizers SFA-5-8 leads to an obvious enhancement in the visible light absorption (300-750 nm) as well as a higher photovoltaic efficiency in the range of (5.53-7.56%). Under optimized conditions, SFA-7 showed outstanding sensitization of nanocrystalline TiO2, resulting in enhancing the visible light absorption and upgrading the power conversion efficiency (PCE) to approximately 7.56% over that reported for the N719 (7.29%). Remarkably, SFA-7 outperformed N719 by 4% in the total conversion efficiency. Significantly, the superior performance of SFA-7 could be mainly ascribed to the higher short-circuit photocurrents (Jsc) in parallel with larger open-circuit voltages (Voc) and more importantly, the presence of different anchoring moieties that could enhance the ability to fill the gaps on the surface of the TiO2 semiconductor. That could be largely reflected in the overall enhancement in the device efficiency. Moreover, the theoretical electronic and photovoltaic properties of all studied sensitizers have been compared with experimental results. All the 2-cyanoacrylamide derivative sensitizers demonstrated robust photovoltaic performance.