For enhancing hydroxide ion conductivity, alkaline stability, and fuel cell performance of quaternaized aromatic/perfluoroaklyl copolymer (QPAF) membranes, ammonium groups attached to the polymer backbone have been investigated. The ammonium groups included dimethylbutylamine (DMBA), dimethylhexylamine (DMHA), and 1,2-dimethylimidazole (DMIm) groups in comparison to the trimethylammonium (TMA) group. DMBA turned to be the optimum ammonium group for QPAF membranes in terms of its high hydroxide ion conductivity based on well-connected and larger phase-separated morphology than that of QPAF-TMA with similar ion exchange capacity (IEC) value. QPAF-DMBA (IEC = 1.33 mequiv g–1) exhibited the highest hydroxide ion conductivity among the tested membranes up to 152 mS cm–1 in water at 80 °C, which was 1.6 times higher than that of QPAF-TMA (95 mS cm–1). In addition, QPAF-DMBA exhibited reasonable alkaline stability in 1 M KOH at 60 °C for 1000 h. The remaining conductivity was 44 mS cm–1 (58%) for QPAF-DMBA, while that for QPAF-TMA was 1.0 mS cm–1 (1%). QPAF-DMBA (IEC = 1.09 mequiv g–1) exhibited excellent stability in 1 M KOH at 80 °C without change in the ion conductivity (22 mS cm–1) for 500 h. The post-test membranes exhibited a minor degradation in QPAF-DMBA as suggested by FT-IR spectra and DMA analyses. An H2/O2 fuel cell was operated with the QPAF-DMBA membrane to achieve the maximum power density of 167 mW cm–2 at the current density of 0.42 A cm–2, which was higher than that (138 mW cm–2) for QPAF-TMA membrane under the same operating conditions.
Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2′-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV–VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.
New series of triazole derivatives coupled with amino acids 1a‐h were obtained via multicomponent reaction of 2‐hydroxy benzaldehyde or 2‐hydroxy acetophenone with thiosemicarbazide and different amino acids. The obtained compounds were reacted with p‐toluinesulfonyl chloride 2 to give the corresponding sulfonamides 3a‐h. Compound 1b was allowed to react with different aromatic aldehydes or cyclic ketone under alkaline conditions to afford the expected imino compounds 4a‐d and 6a‐c, respectively. These compounds were allowed to react with ethyl glycolate to yield the expected thiazolidinone derivatives 5a‐d or 7a‐c, respectively. Structures of the newly synthesized compounds were found to be in accordance with their elemental analyses and spectral data. The obtained compounds exhibited very prominent in vitro and in vivo antihyperglycemic effect at a dose of 40 mg/kg body weight compared to the standard drug gliclazide and control. The antidiabetic effect was investigated using oral glucose tolerance test in normal and non‐insulin‐dependent diabetes mellitus (NIDDM) in STZ‐rat model. Compounds 3a‐h, 5b, 5c, 5d, 7a, 7b, and 7c showed significant activity in lowering blood glucose (more than 80%) compared to the NIDDM control.
A new class of pyrano [3,4-c] [4,3-c]pyrazole has been prepared from 3-benzoyl-2H-chromen-2-one 1. Most of the chromene derivatives showed moderate to high antibacterial activity as compared to the starting material 1.
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