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.

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.

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.

Design and synthesis of novel phthalocyanines as potential antioxidant and antitumor agents starting with new synthesized phthalonitrile derivatives.

New phthalonitrile derivatives formed from reactions of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were considered as the key intermediates for the synthesis of new phthalocyanines. Moreover, new phthalonitrile derivatives 2, 5, 9, 10, 15 and 16 reacted with 1,4-diazabicyclo[2.2.2]octane (DBO) or hydroquinone to afford the corresponding new phthalocyanine dyes 3, 6, 11, 12, 17 and 18. In addition, the cyclotetramerization of phthalic anhydride derivative 20 afforded new phthalocyanine dye 22. Spectral and elemental investigations revealed the structures of the newly synthesized phthalocyanines. The antioxidant and cytotoxic properties of the novel compounds were investigated, and it has been established that compounds 17 and 18 have very strong anticancer and antioxidant action against all cell lines.

Synthesis of novel cyanine dyes as antitumor agents.

In this study, some novel cyanine dyes, 1, 3, and 5-15, were synthesized by a one-pot step reaction of pyridinium salts 2 and/or 4 with benzenaminium salt 1. N-{[1-Chloro-3,4-dihydronaphthalen-2-yl)methylene]benzenaminium} chloride 1 was obtained by the reaction of α-tetralone with Vilsmeier-Haack reagent, followed by a mixture of an equimolar ratio of anilin/ethanol (1:1). All new cyanine dyes were evaluated in vitro for their anticancer activity against two cell lines, that is, HepG2 (human hepatocellular liver carcinoma) and MCF-7 (breast cancer). The obtained results were compared with human lung fibroblasts (WI-38) and Vero cells (derived from the kidney of an African green monkey) as normal cells. In particular, some of these compounds, 6, 9, 13, and 14, were found to be the most potent derivatives against all the cancer cell lines, without effect on the normal cells. According to the structure-activity relationship, compound 13 (IC50 = 8.8 µg/ml) exhibited a higher activity against HepG2 cells, as it contains the azo group and two phenyl rings and due to the presence of the π-conjugated system attached to the two pyridine rings. Compound 6 (IC50 = 8 µg/ml) exhibited a higher activity against MCF-7 cells, as it contains two chlorine atoms and the π-conjugated system of the pyridine rings.

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.

Synthesis and Evaluation of Curcuminoid Analogues as Antioxidant and Antibacterial Agents.

Diazocoupling reaction of curcumin with different diazonium salts of p-toluidine, 2-aminopyridine, and 4-aminoantipyrine in pyridine yielded the arylhydrazones 2a-c. Arylhydrazone of p-toluidine reacted with urea, thiourea, and guanidine nitrate to produce 5,6-dihydropyrimidines. Further reaction of 2a with 2,3-diaminopyrdine in sodium ethoxide solution yielded 1H-pyrido[2,3-b][1,4]diazepine derivative. Bis(2,5-dihydroisoxazole) is obtained from the reaction of 2a with hydroxylamine hydrochloride, while its reactions with hydrazines afforded the respective 4,5-dihydro-1H-pyrazoles. The target compounds were evaluated as antioxidant and antibacterial agents. The tested compounds showed good to moderate activities compared to ascorbic acid and chloramphenicol, respectively.

Synthesis of Pharmacological Heterocyclic Derivatives Based Surfactants.

Synthesis of chromenopyrimidine derivatives and the related fused system carried out by the reaction of chromene derivative 1 with various reagents under suitable reaction conditions. Condensation of stearoyl chloride with these heterocycles, then, propoxylated the products using propylene oxide to produce surface active agents having a twofold capacity as surface and antimicrobial dynamic specialists which may be served in the production of medications, pesticides, beautifying agents or may be utilized as an antimicrobial. Some of the surface properties and antimicrobial activity were resolved.

Synthesis of Novel Arylazothiazolyl-thiophene Dyes for Solar Cell and Nonlinear Optical Materials.

Synthesis and investigation of new donor-acceptor conjugated N-(5-arylazothiazol-2-yl)-2-aminothiophene derivatives with the aim to elucidate the contribution of their interaction with solvent molecules upon intramolecular charge transfer for their potential solar cells application. The UV-visible and emission spectra measurements indicated that the properties of the synthesized dyes had a significant effect on the visible absorption and emission maxima. The effect of the donor and acceptor groups were studied for the nonlinearity based on their HOMO-LUMO band gap energy. The dye-sensitized solar cells (DSSCs) were assembled by using the newly synthesized aryl thiazolyl-thiophene dyes as sensitizers. The promising results of J(SC) (2.46 × 10(-2) and 4.07 × 10(-2) mA/cm(2)), the V(OC) (0.429 V and 0.426 V) and the FF (0.66 %) values obtained comparing with other organic and natural sensitizer were due to the better interaction between the carboxyl and carbonyl groups of aryl azo molecule attached to the thiazolyl nucleus and the surface of TiO(2) porous film.

Nanoformulation and antimicrobial evaluation of newly synthesized thiouracil derivatives.

The present work reports the synthesis of a new series of pyridopyrimidine derivatives. The newly synthesized compounds were characterized by various analytical and spectral techniques. In addition, their antimicrobial activity was evaluated as well as modeling studies were performed to investigate their ability to recognize and bind to the biotin carboxylase (BC)-active site. The results showed a broad spectrum antibacterial and antifungal profile of the synthesized derivatives. Docking results demonstrated that all members of this class of new derivatives were able to recognize the active site of Escherichia coli BC and form different types of bonding interactions with key active site amino acid residues. Besides the compounds with promising antimicrobial activity in addition to 6-aminothiouracil, as control, were incorporated into polycaprolactone nanoparticles to improve their water solubility, permeability through physiological barriers and consequently enhanced therapeutic efficacy. The compounds-loaded nanoparticles were prepared using single emulsion-solvent evaporation technique, and their diameters were found to be in the range 136 ± 30 to 213 ± 28 nm. Transmission electron microscopy (TEM) showed a spherical and dense morphology of the nanoparticles. The results also showed high entrapment efficiency of the synthesized bioactive compounds in the nanoparticles (85 ± 5% to 91 ± 2%) with a desirable in vitro biodegradation and release profiles.

Synthesis and antimicrobial activity of some new benzo and naphthonitrile derivatives.

The reaction of 2-(cyanomethyl)benzonitrile (1) with different diazonium salts gave the corresponding aryldiazenyl derivatives 2a-e which reacted with sodium hydroxide and ethyl chloroacetate and hydroxylamine hydrochloride to afford the corresponding acetamides 4a-e, pyrazoloisoquinolines 6a-e and triazoloisoquinoline derivatives 8a-e, respectively. Moreover, the reaction of 1 with arylidene malononitriles 9a-c afforded dihydronaphthalenes 11a, b and naphthalene derivative 12, respectively. The newly synthesized compounds were characterized by analytical and spectral data. The investigated compounds were screened for their antibacterial activity against Gram-positive bacteria, Gram-negative bacteria and antifungal activity. Among the synthesized compounds, (E)-2-(cyano((4-nitrophenyl)diazenyl)methyl)benzonitrile (2e) exhibited a significant activity toward both Gram-positive, Gram-negative bacteria and exhibit the most potent in vitro antifungal with MIC's (6.25 µg/mL) against Botrytis fabae.

Synthesis and pharmacological screening of novel meso-substituted porphyrin analogs.

A novel series of mesotetrakis[aryl]-21H,23H-porphyrin derivatives 2a-j was synthesized from the condensation of aldehyde derivatives 1a-j with pyrrole in the presence of p-toluenesulfonic acid. The synthesized porphyrins were considered as a model to study the free radical-induced damage of biological membranes and the protective effects of these porphyrins. It was found that these compounds effectively inhibit the free radical-induced oxidative hemolysis of red blood cells. Compounds 2c and 2d which bear a sulfur atom, a nitro group, and a chlorine atom exhibited markedly higher antihemolysis activity than the other analogous. Compounds 2a, 2c, 2d, and 2j showed the highest protection activity against DNA damage induced by the bleomycin-iron complex. Compounds 2d, 2f, 2i, and 2j were proved to exhibit antioxidative activity.

Synthesis and antioxidant and antitumor activity of novel pyridine, chromene, thiophene and thiazole derivatives.

2-Tosylacetonitrile (1) when reacted with α,ß-unsaturated nitriles 2a-c or a mixture of formaldehyde and 3-amino-2-substituted-pent-2-endinitriles 6a,b yielded pyridine derivatives 3a-c and 9a,b, respectively, while when subjected to react with salicylaldehyde yielded chromene derivatives 4 and 5, subsequently. The behavior of thiocarbamoyl derivative 10 derived from 1 towards some α-halogenated compounds have been investigated as well as its behavior towards elemental sulfur and phenyl isothiocyanate. Newly synthesized compounds were screened for their antioxidant activity, erythrocytes haemolysis and bleomycin-independent DNA damage. Some of the tested compounds exhibited promising activities.

Synthesis and antimicrobial activity of some new 4-hetarylpyrazole and furo[2,3-c]pyrazole derivatives.

In continuation of our efforts to find a new class of antimicrobial agents, a series of 4-hetarylpyrazoles and furo[2,3-c]pyrazoles were prepared via the reaction of 2-chloro-1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)ethanone (1) with an appropriate nucleophilic reagents. These compounds were screened for their antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Bacillus thuringiensis), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and antifungal activity against Fusarium oxysporum and Botrytis fabae. Among the synthesized compounds, 1-(5-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazole-4-yl)-2-methylfuran-3-yl)ethanone (12) showed equal activity with chloramphenicol against B. subtilis (MIC 3.125 µg/mL), while its activity was 50% lower than of chloramphenicol against B. thuringiensis. N-[(4Z)-3-Methyl-1-phenyl-1H-furo[2,3-c]pyrazol-4(5H)-ylidene]-1H-benzimidazol-2-amine (7) and 2-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-4H-furo[3,2-c]chromen-4-one (13) were found to exhibit the most potent in vitro antifungal activity with MICs (6.25 µg/mL) against B. fabae and F. oxysporum.

Synthesis and molluscicidal activity of some new thiophene, thiadiazole and pyrazole derivatives.

The base-catalyzed reaction of benzoyl acetone 1 with phenyl isothiocyanate yields the non-isolable intermediate 2. Treatment of 2 with dilute HCl afforded the corresponding thiocarbamoyl derivative 3. Reaction of the intermediate 2 with phenacyl bromide, ethyl bromoacetate, chloroacetonitrile, chloroacetyl chloride, bromodiethyl malonate and chloroacetone afforded the corresponding thiophene derivatives 5, 8, 15 and 17. The thiocarbamoyl derivative 3 reacts with arylazophenacyl bromide and/or hydrazine hydrate to afford the corresponding thiadiazole and pyrazole derivatives 20a-c and 22, respectively. These new synthesized compounds show generally a moderate molluscicidal activity to Biomphalaria alexandrina snails.

Synthesis and antimicrobial activity of some new heterocycles incorporating antipyrine moiety.

2-cyano-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide (1) was utilized as key intermediate for the synthesis of some new coumarin 2, pyridine 3, pyrrole 4, thiazole 7, pyrido[2',3':3,4][pyrazolo[5,1-c]triazine and aminopyrazole 9. Treatment of aminopyrazole 9 with nitrous acid, 1,3-dicarbonyl compounds, enaminone, and DMF-DMA led to the formation of pyrazolo[3,4-d]triazine 10, pyrazolo[1,5-a]pyrimidines 11, 12, 14, and pyrazolo[3,4-d]pyrimidine 13, respectively. Condensation of 9 with isatin afforded Schiff base 16. The newly synthesized compounds were characterized by IR, 1H NMR and mass spectral studies. Representative compounds of the synthesized products were tested and evaluated as antimicrobial agents.

Synthesis and antimicrobial evaluation of some new thiazole, thiazolidinone and thiazoline derivatives starting from 1-chloro-3,4-dihydronaphthalene-2-carboxaldehyde.

The thiosemicarbazones (3 and 6) and N-arylidene cyanoacetohydrazide (12) were prepared and used as key intermediates for the synthesis of 4-thiazolidinones (4, 5, 7-9), thiazoles (10a,b and 11a-d) and thiazoline (13) derivatives. Treatment of 13 with a mixture of triethylorthoformate and acetic anhydride afforded thiazolo[5,4-d]pyrimidinone derivative (14). The newly synthesized compounds were characterized by IR, (1)H NMR and mass spectral studies. Representative compounds of the synthesized products were tested and evaluated as antimicrobial agents.