Porcine Kidney Tissue Based Membrane Electrode for Glucosamine-6-Phosphate

Abstract

It is shown that porcine kidney tissue can serve as an effective biocatalyst in the construction of a potentiometric membrane electrode with response and selectivity for glucosamine-6-phosphate. Electrodes using this tissue material in conjunction with NH₃ gas sensing probes yield good response to glucosamine-6-phosphate in the 5 × 10^?5 M to 10^?3 M range and retain activity for at least 3 weeks. The resulting sensors have good selectivity when operated at an optimum pH of 9.25.     

Comparison of CO2 Reduction Performance with NH3 and H2O between Cu/TiO2 and Pd/TiO2

The aim of this study is to clarify the effect of doped metal type on CO₂ reduction characteristics of TiO₂ with NH₃ and H₂O. Cu and Pd have been selected as dopants for TiO₂. In addition, the impact of molar ratio of CO₂ to reductants NH₃ and H₂O has been investigated. A TiO₂ photocatalyst was prepared by a sol-gel and dip-coating process, and then doped with Cu or Pd fine particles by using the pulse arc plasma gun method. The prepared Cu/TiO₂ film and Pd/TiO₂ film were characterized by SEM, EPMA, TEM, STEM, EDX, EDS and EELS. This study also has investigated the performance of CO₂ reduction under the illumination condition of Xe lamp with or without ultraviolet (UV) light. As a result, it is revealed that the CO₂ reduction performance with Cu/TiO₂ under the illumination condition of Xe lamp with UV light is the highest when the molar ratio of CO₂/NH₃/H₂O = 1:1:1 while that without UV light is the highest when the molar ratio of CO₂/NH₃/H₂O = 1:0.5:0.5. It is revealed that the CO₂ reduction performance of Pd/TiO₂ is the highest for the molar ratio of CO₂/NH₃/H₂O = 1:1:1 no matter the used Xe lamp was with or without UV light. The molar quantity of CO per unit weight of photocatalyst for Cu/TiO₂ produced under the illumination condition of Xe lamp with UV light was 10.2 μmol/g, while that for Pd/TiO₂ was 5.5 μmol/g. Meanwhile, the molar quantity of CO per unit weight of photocatalyst for Cu/TiO₂ produced under the illumination condition of Xe lamp without UV light was 2.5 μmol/g, while that for Pd/TiO₂ was 3.5 μmol/g. This study has concluded that Cu/TiO₂ is superior to Pd/TiO₂ from the viewpoint of the molar quantity of CO per unit weight of photocatalyst as well as the quantum efficiency.     

ORGANISCHE PHOSPHORVERBINDUNGEN 86.1 HERSTELLUNG UND EIGENSCHAFTEN VON ω-PHOSPHINYL-α-AMINOALKYL-CARBONSÄUREN

Abstract

The synthesis, chemical and spectral properties of ω-methylphosphinyl-α-aminoalkylcarbonic acids, CH₃ (HO)P(O)(CH₂)_n CH(NH₂)CO₂H, n=3, 4, 5 or 6, are described. In contrast to the corresponding phosphonic acid derivatives these compounds exhibit no anticonvulsive and NMDA-antagonistic properties.     

Fe3O4@SiO2–NH2 core-shell nanocomposite as an efficient and green catalyst for the multi-component synthesis of highly substituted chromeno[2,3-b]pyridines in aqueous ethanol media

ABSTRACT

An efficient and green approach for synthesizing chromeno[2,3-b]pyridine derivatives through one-pot three-component reactions of salicylaldehydes, thiols, and malononitrile has been developed by Fe₃O₄@SiO₂–NH₂ nanocatalyst in aqueous ethanol media under re?ux conditions. The present procedure provides several advantages such as environmentally benign, straightforward, excellent yields, short reaction times, cost-effective, good recyclability, little catalyst loading, and facile catalyst separation for the preparation of chromeno[2,3-b]pyridines as important privileged medicinal scaffold. In addition, aminopropyl-coated Fe₃O₄@SiO₂ nanoparticles were fully characterized by scanning electron microscopy, X-ray diffraction, energy dispersive analysis of X-ray, vibrating sample magnetometer, and FT-IR analysis.     

Surfactant-assisted hydrothermal crystallization of nanostructured lithium metasilicate (Li2SiO3) hollow spheres: II—Textural analysis and CO2-H2O sorption evaluation

In a previous work, the synthesis and structural-microstructural characterization of different nanocrystalline lithium metasilicate (Li₂SiO₃) samples were performed. Then, in this work, initially, a textural analysis was performed over the same samples. Li₂SiO₃ samples prepared with a non-ionic surfactant (TRITON X-114) presented the best textural properties. Therefore, this sample was selected to evaluate its water vapor (H₂O) and carbon dioxide (CO₂) sorption properties. Sorption experiments were performed at low temperatures (30-80 °C) in presence of water vapor using N₂ or CO₂ as carrier gases. Results clearly evidenced that CO₂ sorption on these materials is highly improved by H₂O vapor, and of course, textural properties enhanced the H₂O-CO₂ sorption efficiency, in comparison with the solid-state reference sample.     

ORGANISCHE PHOSPHORVERBINDUNGEN 791 HERSTELLUNG UND EIGENSCHAFTEN VON α-AMINO-ω-CARBOXYALKYLPHOSPHON-UND-PHOSPHINSÄUREN

Abstract

The synthesis, chemical and spectral properties of α-amino-ω-carboxyalkylphosphonic acids, (HO)₂P(O)CH(NH₂)(CH₂) _x CO₂H, x = 2 to 6, and of α-amino-ω-carboxyalkyl-methylphosphinic acids CH₃(HO)P(O)CH(NH₂)(CH₂) _x CO₂H, x = 2 to 6 are described and the fungicidal activity of some of these derivatives is reported.     

Photocatalytic Activities of FeNbO4/NH2-MIL-125(Ti) Composites toward the Cycloaddition of CO2 to Propylene Oxide

Photocatalytic utilization of CO₂ in the production of value-added chemicals has presented a recent green alternative for CO₂ fixation. In this regard, three FeNbO₄/NH₂-MIL-125(Ti) composites of different mole ratios were synthesized, characterized using Powder X-ray diffraction (PXRD), UV–vis diffuse reflectance spectroscopy (UV-Vis DRS), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). PXRD patterns confirm the co-existence of the parent components in the prepared composites. Moreover, the surface area increased as the mole percent of NH₂-MIL-125(Ti) in the composites increased due to the large surface area of NH₂-MIL-125(Ti). Prepared composites were investigated for the photocatalytic insertion of CO₂ into propylene oxide. FeNbO_4(75%)/NH₂-MIL-125(Ti)_(25%) showed the highest percent yield of 52% compared to the other two composites. Results demonstrate the cooperative mechanism between FeNbO₄ and NH₂-MIL-125(Ti) and that the reaction proceeded photocatalytically.     

ORGANISCHE PHOSPHORVERBINDUNGEN 85.1 HERSTELLUNG,EIGENSCHAFTEN UND BIOLOGISCHE WIRKUNG VON N-AMINOGLYPHOSATE UND AZAGLYPHOSATE

Abstract

The synthesis and the chemical, physical and spectral properties of N-aminoglyphosate ethylester (hydrazino-N′-carbethoxymethyl-N′-methylphosphonic acid) 4a, H₂OPCH₂N(NH₂)CH₂CO₂C₂H₅, of hydrazino-N′-carbethoxymethyl-N′-methyl-P-methylphosphinic acid 4b, CH₃(HO₂)PCH₂N(NH₂)-CH₂CO₂C₂H₅, and of azaglyphosate ethylester (hydrazino-N-carbethoxymethyl-N-methyl-phosphonic acid 9, H₂O₃PCH₂NHNHCH₂CO₂C₂H₅, are described. 4a, 9 and 10 exhibit plant growth regulating properties.     

Infrared studies of surface carbonate binding to diimine-tricarbonyl Re(I) and Mn(I) complexes in mesoporous silica

Abstract

Diimine-tricarbonyl Re(I) and Mn(I) complexes have demonstrated interesting activity in photocatalytic and electrochemical CO₂ reduction. In this study, we take a surface chemistry approach to investigate interactions of CO₂ with Re(I) and Mn(I) complexes in the presence of triethylamine. The molecular complexes were adsorbed on the surface of a mesoporous silica. Under dark conditions, formation of metal-carbonate adducts was observed by infrared spectroscopy in the presence of CO₂, triethylamine, and surface silanol groups. The Langmuir adsorption model was utilized to extract quantitative information regarding surface carbonate binding to the two molecular complexes. The results indicate that binding of carbonate was much stronger on the Re(I) center than on Mn(I), consistent with prior observations regarding the relative activities of these complexes in CO₂-reduction catalysis.     

Nonaqueous synthesis of uniform polyaniline nanospheres Via cellulose acetate template

In acetone solution, uniform polyaniline (PANI) nanospheres have been successfully synthesized by using cellulose acetate (CA) as a single template, which provides the first example of uniform PANI nanospheres synthesized in nonaqueous system. Our result exhibits that the CA micelle in nonaqueous medium plays a unique role in controlling size and uniformity of PANI nanospheres. A detail formation mechanism for the uniform PANI nanospheres has been proposed. In addition, the gas sensitivity and time response of the PANI nanospheres to NH₃ gas have been investigated, which shows superior gas sensing performance even at 1 ppm of NH₃ gas. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Reactions of isomeric 3,6- and 3,5-di-tert-butyl-ortho-benzoquinones with NH3

The interaction of 3,6-di-tert-butyl-ortho-benzoquinone (1) and 3,5-di-tert-butyl-ortho-benzoquinone (2) with NH₃ in water—alcohol medium and with (NH₄)₂CO₃ in a solid phase has been studied. Redox processes with participation of a nucleophile of the medium take place for1, while2 reacts with NH₃ at the carbonyl group with transformation of the quinone imide. The mechanism of redox transformation of1 has been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1789–1793, September, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 94-03-08653).     

Direct Potentiometric Measurement of NH4H2BO3 Following a Kjeldahl Distillation

Abstract

A method is described for the direct potentiometric measurement of NH₄H₂BO₃, following a Kjeldahl distillation. The NH₃ is distilled into a H₃BO₃ solution, and the activity of the NH₄H₂BO₃ is measured using a cation electrode sensitive to NH₄ ⁺ and an anion electrode sensitive to H₂BO₃. The method has been used to determine nitrogen in dried blood samples with assigned N values, and the potentiometric values agreed with the titrimetric results.     

Intramolecular C–H insertion catalyzed by dirhodium(II) complexes using CO2 as the reaction media

Abstract

In this work, the intramolecular C–H insertion of diazoacetamides catalyzed by dirhodium(II) complexes and using CO₂ as solvent is disclosed. The expected lactams were obtained in yields over 97%. The asymmetric intramolecular C–H insertion was also achieved and the β-lactam 14 was obtained in >97% yield and 65% ee using the chiral dirhodium(II) catalyst Rh₂(S-PTTL)₄. Finally, the dirhodium(II) complex Rh₂(OAc)₄ was used in two consecutive cycles in which complete conversion to the lactam was observed.     

Studies on the effects of coated Li2CO3 on lithium electrode

Although a lithium metal anode has a high energy density compared with a carbon insertion anode, the poor rechargeability prevents the practical use of anode materials. A lithium electrode coated with Li₂CO₃ was prepared as a negative electrode to enhance cycleability through the control of the solid electrolyte interface (SEI) layer formation in Li secondary batteries. The electrochemical characteristics of the SEI layer were examined using chronopotentiometry (CP) and impedance spectroscopy. The Li₂CO₃-SEI layer prevents electrolyte decomposition reaction and has low interface resistance. In addition, the lithium ion diffusion in the SEI layer of the uncoated and the Li₂CO₃-coated electrode was evaluated using chronoamperometry (CA).     

Aldol Condensations Catalyzed by PEG400 and Anhydrous K2CO3 Without Solvent

Abstract

Aldol condensations of aromatic aldehydes with ketones under solvent‐free conditions to synthesize α,β‐unsaturated ketones in good to excellent yields using PEG400 and powdered anhydrous K₂CO₃ as catalysts at 90 °C and 120 °C are described.     

Efficient Synthesis of Novel 3-[5-(1H-Benzimidazol-2-Ylmethanesulfonyl)-4-Phenyl-4H-(1,2,4)Triazol-3-Yl]-1H-(1,8)Naphthyridin-4-One Derivatives

Abstract

of 1,4-dihydro-4-oxo-1,8-naphthyridine-3-carbohydrazide (4) with substituted phenyl isothiocyanates (5) in ethanol under reflux for 30 min gave thiosemicarbazide derivatives 6, which on cyclization in 2N NaOH under refluxing conditions for 1 h resulted in 3-(5-mercapto- 4-phenyl-4H-1,2,4-triazol-3-yl)-1,8-naphthyridin-4(1H)-one (7). Alternatively, 7 could also be prepared from following sequence of reactions, i.e., 4 → 8 → 7. In another sequence of reactions, condensation of 7 with chloroacetic acid in dimethylformamide (DMF) and K₂CO₃ as a mild base at 120 °C for 2 h resulted in 2-((5-(1,4-dihydro-4-oxo-1,8-naphthyridin-3-yl)-4-phenyl-4H-1,2,4-triazol-3-yl)sulfanyl)acetic acid (10). The latter, on reaction with substituted o-phenylenediamine (11) in 6N HCl for 4 h yielded 3-(5-((1H-benzo[d]imidazol-2-yl)methylthio)-4-phenyl-4H-1,2,4-triazol-3-yl)-1,8-naphthyridin-4(1H)-one (12). Alternatively, 12 could also be prepared by reacting 7 with 13 in DMF and K₂CO₃ as a mild base at 120 °C for 2 h, followed by oxidation with H₂O₂ resulting in the corresponding sulfonyl derivatives 14.     

Reactions of cisplatin hydrolytes, cis-[Pt(15NH3)2(H2O) 2]2+, with N-acetyl-L-cysteine

The reaction of cis-[Pt(¹⁵NH₃)2(H₂O) ₂] ²⁺ (3) with N-acetylcysteine [H₃accys] was investigated in aqueous solution. In this reaction, the ammine in the platinum complex formed was liberated. A mono-dentate sulfur-boundplatinum(II) product cis-[Pt(¹⁵NH₃)₂(H₂O)(H2accys-S)]⁺ (7) and six-membered che-late ring complex cis-[Pt(¹⁵NH₃)₂ (Haccys-S,O)] (8) were formed in solution. The dinuclear sulfur-bridged complex 9, giving a broad peak in ¹⁵N NMR, was also observed, but only present in very tiny amounts. The mass spectrometry (ES-MS) was undertaken from this re action, and the product detected was only the dinuclear sulfur bridged platinum species and species related to it by ammine loss.     

Kinetics and rate-limiting mechanisms of dolomite dissolution at various CO2 partial pressures

Techniques of rotating-disk and catalyst were used in investigating the kinetics of dolomite dissolution in flowing CO₂-H₂O system. Experiments run in the solutions equilibrated with various CO₂ partial pressures (P_{CO 2} ) from 30 to 100000 Pa. It shows that dissolution rates of dolomite are related with rotating speeds at conditions far from equilibrium. This was explained by modified diffusion boundary layer (DBL) model. In addition, the dissolution rates increase after addition of carbonic anhydrase (CA) to solutions, where the CA catalyzes CO₂ conversion. However, great differences occur among various CO₂ partial pressures. The experimental observations give a conclusion that the modified DBL model enables one to predict dissolution rates and their behaviour at various P_{CO 2} with satisfactory precision at least far from equilibrium.     

Oxidative dehydrogenation of ethylbenzene over γ-Al2O3 supported ceria-lanthanum oxide catalysts: Influence of Ce/La composition

A series of CeO₂/γ-Al₂O₃ (CA) catalysts with CeO₂ loading of 5, 10, 15 and 20 wt% were prepared by a facile incipient wetness impregnation technique. Another series of La³⁺ doped catalysts (LCA) were prepared, wherein, 1, 3 and 5 wt% of La₂O₃ was doped in 15 wt%CeO₂/γ-Al₂O₃, which were designated as 1LCA, 3LCA and 5LCA catalysts. Both CA and LCA catalysts were characterized by thermogravimetric analysis (TGA), BET surface area, X-ray diffraction (XRD), Infrared (FT-IR) spectroscopy, UV–vis diffuse reflectance spectra (UV–vis DRS), transmission electron microscopy (TEM), temperature programmed desorption of NH₃ (TPD of NH₃) temperature programmed reduction (TPR), CO₂ pulse chemisorption and O₂ pulse chemisorption techniques. All CA and LCA catalysts were evaluated for ethylbenzene (EB) oxidative dehydrogenation to styrene (ST) in vapor phase under atmospheric pressure with CO₂ as an oxidant. Albeit CA and LCA catalysts are active, 15CA and 3LCA catalysts are found to be the best catalysts of the respective series. Apart from compatible acid-base and redox characteristics, sufficient amount of solid solution clusters (Ce_xLa_1-xO_2-δ) are responsible for superior activity of 3LCA catalyst.     

Zeolite and potting soil sorption of CO2 and NH3 evolved during co-composting of grape and tobacco waste

The gaseous byproducts produced during the composting of different kinds of solid waste are carbon dioxide (CO₂) and ammonia (NH₃). CO₂ is a greenhouse gas and NH₃ is a toxic and corrosive air pollutant so, they must be removed from exhaust gases prior to release into the atmosphere. The purpose of this work was to investigate the sorption of CO₂ and NH₃, evolved during composting, on zeolite and potting soil. The composting of the mixture of grape waste (GW) and tobacco waste (TW) in the mass ratio GW: TW = 55: 45 (dry mass basis) was carried out under forced aeration (0.645 L min^?1 kg^?1) in a column reactor (10 L) under adiabatic conditions over 21 days. Adsorption of the gases evolved was carried out in the fixed-bed column reactor (0.166 L). The most important physical-chemical characteristics of the composting mass and adsorbents and the evolved CO₂ and NH₃ were closely monitored. The highest CO₂ and NH₃ concentrations were measured at the thermophilic stage and the cooling stage of composting, respectively. The results showed that zeolite and potting soil were good adsorbents for the sorption of CO₂ and NH₃. The zeolite adsorbed 31 % of the evolved CO₂ and the entire concentration of ammonia, whilst the potting soil adsorbed 3 % of CO₂ and 49 % of NH₃ from the exhaust gases.