Nucleophilic,Heterocyclic, Carbene-Catalyzed,Solvent-Free,One-Pot Synthesis of Polyhydroquinolines via Multicomponent Hantzsch Reaction: An Efficient and Ecofriendly Approach

A simple, efficient, and ecofriendly one-pot method has been reported for the synthesis of polyhydroquinolines in excellent yield using nucleophilic heterocyclic carbene as catalyst. The generalized approach is the Hantzsch four-component reaction of aromatic aldehyde, ethyl acetoacetate, cyclic 1,3-diketone, and ammonium acetate.     

Improvement of cycling stability of LiMn2O4 cathode by Fe2O3 surface modification for Li-ion battery

The surface of spinel LiMn₂O₄ was modified with Fe₂O₃ (1.0, 2.0, 3.0, 4.0, and 5.0 wt%) by a simple sol-gel method to improve its electrochemical performance at room temperature. Compared with bare LiMn₂O₄, surface modification improved cycling stability of the material. Among the surface-modified cathode materials, the 3.0- and 4.0-wt% surface-modified cathodes have lesser capacity loss than the others. While the bare LiMn₂O₄ showed 25.4 % capacity loss in 70 cycles at room temperature, 3.0 and 4.0 wt% of Fe₂O₃-modified LiMn₂O₄ only exhibited the capacity loss of 2.6 and 2.3 % in 70 cycles at room temperature, respectively. The structure and phase were identified with X-ray diffractometer along with the lattice constant calculated by a Win-Metric program.     

Specific capacitance of CoS encapsulated g-C3N4 core shell nanocomposite as extremely efficient counter electrode in quantum dots solar cells

Journal of Solid State Electrochemistry - In this context, the electrical conductivity and surface activity of cobalt sulphide (CoS) as counter electrode CE is improved by incorporating with...     

Influence of the processing solvent on the photoactive layer nanomorphology of P3HT/PC60BM solar cells

In this article, it is demonstrated that doctor blading of thin poly‐3‐hexylthiophene/phenyl‐C₆₁‐butyric acid methyl ester (1/1) bulk‐hetero junction films from toluene leads to an improved nanocrystallinity, when compared with their unannealed chlorobenzene processed counterparts. This difference in morphology was demonstrated by solid‐state NMR and Rapid Heating Cooling Calorimetry (RHC), being useful complementary techniques to investigate the active layer morphology of photovoltaic devices. An increased PC₆₀BM nanocrystallinity is indicated by several NMR relaxation decay times (T_1C, T_1H, and T_1ρH) and confirmed by an increase of the melting enthalpy in RHC experiments. An improved solar cell performance further strengthens this conclusion. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Removal of the copper catalyst from atom transfer radical polymerization mixtures by chemical reduction with zinc powder

Simple mixing of an atom transfer radical polymerization (ATRP) mixture with zinc powder was demonstrated to result in rapid decolorizing of the solution and precipitation of elemental copper, using small amounts of silica gel as seeding material. The experiments revealed that the chemical reduction of copper by wetted zinc powder (i.e., 0.325 g/mmol copper) is fast and completed within less than 5 min. UV spectra of the filtered polymer solution showed no any trace of copper. Terminal bromoalkyl groups of the polymers in the ATRP solution were determined to be unchanged by short‐term contact with zinc powder at room temperature and a nearly complete reductive dehalogenation takes place only after 24 h of interaction, as evidenced by reaction of elemental zinc with a model compound, ethyl bromoacetate. Indeed, poly(methyl methacrylate) (PMMA) sample (M_n: 7900, polydispersity index: 1.09) isolated from ATRP mixture after the copper removal a by short contact with zinc powder (i.e., 15 min) was determined “still living” as confirmed by chain extension with styrene, ethyl acrylate, and t‐butyl acrylate monomers to give block copolymers. The presence of acetic acid was demonstrated to accelerate reductive dehalogenation of PMMA end‐groups by zinc and yields nonliving polymer within 2 h. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis and Effect of Some 5-Alkyl-1,3,4-Triazole-2-Thione Derivatives on Corrosion Behavior of Molybdenum Electrode in Hydrochloric Acid

A novel series of self-assembled surfactants derived from 5-alkyl-1,3,4-triazole-2-thione have been synthesized. The purity of surfactants synthesized was checked by rutinary methodologies (FTIR spectroscopy, ¹H-NMR, MS and elemental analysis). Their surface active properties at equilibrium in water at 25°C were determined. Also, the inhibitive effect of these compounds, in the case of molybdenum in acid medium, was investigated thoursough galvanostatic and galvanodynamic techniques. Galvanodynamic polarization data indicates that these surfactants act as very good inhibitors of molybdenum in hydrochloric acid both for cathode and anode. Galvanostatic measurement has the same trend of inhibitive effect as that of the galvanodynamic polarization data, which indicate the formation of a protective layer on the metal surface by the adsorption of surfactants molecules.     

Ecofriendly and highly efficient microwave-induced synthesis of novel quinazolinone-undecyl hybrids with in vitro antitumor activity

Abstract

Novel N-alkyl-quinazolin-4-one derivatives 3–5 were obtained from reaction of 6-Iodo-2-undecylquinazolin-4(3H)-one (2) with different alkyl halides. Hydrazinolysis of compound 5 gave the acetohydrazide 6 which reacted with different carbon electrophiles to produce 2-undecyl-4(3H)-quinazolinone derivatives. The new products were obtained by either conventional method or by microwave assisting technique and the structure of all products was confirmed by elemental and spectral data. The ecofriendly microwave provides an efficiency over than conventional method in many aspects. All the synthesized products were tested in vitro against a panel of three human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, colon cancer HCT-116, and mammary gland breast MCF-7. Almost all of the tested compounds showed satisfactory activity.     

Synthesis and characterization of new cyclotriphosphazene compounds

In the present study, spiro (1a), dispiro (1b, 2, 3), per-substituted spermine-bridged (6–9) and dispiroansa spermine (10) derivatives of cyclotriphosphazene have been synthesized. The structures of the novel compounds (1b, 6–10) have been characterized by elemental analysis, FTIR, mass spectrometry, ¹H and ³¹P NMR spectroscopy. The molecular structures of 1b, 2, 8, and 10 were determined by single crystal X-ray crystallography. In order to investigate the anti-tumour properties of the newly synthesized cyclotriphosphazene derivatives, in vitro cytotoxic activity test (MTT assay) has been performed using HT-29 (human colon adenocarcinoma) and Hep2 (human epidermoid larynx carcinoma) cell lines. The result of the MTT assay showed that while compound 1a has cytotoxic effect on both Hep2 and HT-29 cell lines, compound 3 has only cytotoxic effect towards the Hep 2 cells.