Fe nano particles mediated C-N bond-forming reaction: Regioselective synthesis of 3-[(2-chloroquinolin-3-yl)methyl]pyrimidin-4(3H)ones

An efficient and regioselective N-alkylation of 4(3H)-pyrimidone with various electrophiles in the presence of Fe nano particle is reported. The catalyst initiates N-alkylation of amides by alkyl chlorides. The reaction of equimolar 4(3H)-pyrimidone and 2-chloro-3-(chloromethyl)quinolines in the presence of KOH and Fe nano particle (5 mol %) in DMSO solution under reflux condition formed 3-[(2-chloroquinolin-3-yl]methyl)pyrimidin-4(3H)ones.     

Photophysical properties of [60]fullerenes and phthalocyanines embedded in ordered mesoporous silica films annealed at various temperatures

The photophysical properties of fullerene and/or phthalocyanine dyes embedded in ordered mesoporous silica films and the influence of annealing temperature on the nature of the immobilized dye molecules has been investigated using photoluminescence (PL) and diffuse reflectance (DR) studies. The PL and DR studies show that fullerene (C60) and/or zinc phthalocyanine (ZnPc) molecules incorporated into transparent mesoporous silica films, via either sol-gel or grafting routes, exist predominantly in monomeric form. Careful choice of annealing temperature, between 25 and 225 degrees C, can further enhance monomeric dispersion. For C60-containing films, monomeric dispersion of fullerene was observed for annealing temperatures up to 175 degrees C for sol-gel derived films and 225 degrees C for grafted films. Both sol-gel and grafted ZnPc-containing films showed evidence of monodispersed phthalocyanine for annealing temperatures up to 225 degrees C. In general, annealing temperatures in the range 125-175 degrees C were found to yield optimal monodispersion of the dye molecules. When both C60 and ZnPc were incorporated into the silica films, no evidence of interaction between the dyes, i.e., charge-transfer transitions or the formation of fullerene/phthalocyanine charge-transfer complexes, was observed. This suggests that embedded fullerene and phthalocyanine molecules may be used for the preparation of solid-state optical limiters, based on reverse saturable absorption, where monomeric dispersion of the dye molecules is important.     

Estimation and Comparison of Pore Charge on Titania and Zirconia Membranes Prepared by Sol-Gel Route Using Zeta Potential Measurement

An attempt has been made to synthesize ceramic titania and zirconia membranes by sol-gel process by filtering respective viscous colloidal sol through microporous alumina support and gelling followed by sintering at 400°C and 470°C respectively. The static charge on the pores of the so formed membranes and the pore size distribution determine the applicability in filtering colloidal solution. The mean pore size from SEM were found to be 0.65 m and 0.54 m for titania and zirconia membranes respectively with 1.47 × 10⁷/cm² as pore density for both. The filtration characteristics during membrane layer formation showed that the membrane layer formation started after 35 minutes in the case of titania membrane and 40 minutes in the case of zirconia membrane. From the gravimetric estimation of water content of the membranes the thickness of the membrane was found out to be 3 m and the porosity was found out to be 0.30 for both the cases. The particle charge density was estimated from the zeta potential and the particle size. The pore charge density was estimated from the particle charge density, pore density, pore diameter and the thickness of the membrane layer. The membrane pore charge density was found to vary between 3 to –1 Coulombs/cm² in the case of titania membrane and 7 to –0.5 Coulombs/cm² in the case of zirconia membrane in the pH range 1–12.     

Adsorption and expression of penicillin G acylase immobilized onto methacrylate polymers generated with varying pore generating solvent volume

Adsorption and expression of penicillin G acylase was studied on macroporous methacrylate polymer beads of differing pore volume, generated with kerosene. The absorption and expression of the penicillin G acylase was dependent on pore volume. Maximum expression of 57% of adsorbed enzyme was obtained on beads synthesized with 40 mL of kerosene, indicating minimum pore-diffusion limitations.     

Cobalt(II) nitrate complexes with piperidin-4-ones

Ten cobalt(II) nitrate complexes with variously substituted 2,6-diphenylpiperidin-4-ones (L¹)–(L¹⁰) have been prepared and characterized by elemental analysis, molecular weight determination, molar conductance and magnetic, thermal, polarographic and spectral studies. The formula [Co(L)₂(H₂O)₄](NO₃)₂ has been assigned to complexes (2–5), (7), (8) and (10) and [Co(L)₂(H₂O)₂(NO₃)]NO₃ to complexes (1), (6) and (9). Although piperidin-4-ones have two coordinating sites, namely the ring nitrogen and the carbonyl group, i.r., and polarographic studies indicate that only the ring nitrogen is involved in coordination. Electronic spectral data reveal that these complexes have octahedral geometry.     

Catalytic performance of polymer-supported ionic liquids in the synthesis of glycerol carbonate from glycerol and urea

Research on Chemical Intermediates - Ionic liquids (ILs) immobilized onto a structurally modified Merrifield peptide resin (MPR) were prepared through the reaction of imidazole with alkoxylated...     

Dye-sensitised solar cells with iodine-free discotic electrolytes

Discotic mesogenic molecules viz., hexahexylthiotriphenylene (HHTT) and hexahexyloxytriphenylene were applied, for the first time, as iodine-free redox electrolyte in dye-sensitised solar cells (DSSCs). The cell shows open circuit voltage (V_oc) of 0.95 V, short circuit current density (J_sc) of 0.534 mA/cm², fill factor 88.24% and overall power conversion efficiency (η) 0.45% in a typical fluorine doped tin oxide/TiO₂/N719/HHTT/Pt DSSC configuration. Scanning electron microscopy was used to study surface profile of electrolytes while electrochemical impedance spectroscopy was used to understand the electrochemical behaviour of electrolytes. The photovoltaic parameters were measured under standard conditions using Oriel solar simulator class AAA. These first results demonstrate the potential of the discotic molecules as charge transporter and mediator and show promise to be used in iodine-free DSSCs.     

Microbial reduction of sulfur dioxide in immobilized,mixed cultures of sulfate-reducing bacteria with sewage digest as carbon and energy source

Applied Biochemistry and Biotechnology - A considerable increase in soluble COD and organic acid concentrations was achieved in a continuous process for AD-MSS medium preparation. This reactor...     

Electrocatalytic oxidation of ethylene glycol on Pt and Pt-Ru nanoparticles modified multi-walled carbon nanotubes

The synthesis and characterization of catalysts based on nanomaterials, supported on multi-walled carbon nanotubes (CNT) for ethylene glycol (EG) oxidation is investigated. Platinum (Pt) and platinum-ruthenium (Pt-Ru) nanoparticles are deposited on surface-oxidized multi-walled carbon nanotubes [Pt/CNT; Pt-Ru/CNT] by the aqueous solution reduction of the corresponding metal salts with glycerol. The electrocatalytic properties of the modified electrodes for oxidation of ethylene glycol in acidic solution have been studied by cyclic voltammetry (CV), and excellent activity is observed. This may be attributed to the small particle size of the metal nanoparticles, the efficacy of carbon nanotubes acting as good catalyst support and uniform dispersion of nanoparticles on CNT surfaces. The nature of the resulting nanoparticles decorated multiwalled carbon nanotubes are characterized by scanning electron microscopy (SEM) and transmission electron microscopic (TEM) analysis. The cyclic voltammetry response indicates that Pt-Ru/CNT catalyst displays a higher performance than Pt/CNT, which may be due to the efficiency of the nature of Ru species in Pt-Ru systems. The fabricated Pt and Pt-Ru nanoparticles decorated CNT electrodes shows better catalytic performance towards ethylene glycol oxidation than the corresponding nanoparticles decorated carbon electrodes, demonstrating that it is more promising for use in fuel cells.