Selective nonanal molecular recognition with SnO2 nanosheets for lung cancer sensor

SnO₂ nanosheets were developed to detect nonanal gas in the order of ppb which was a marker of lung cancer. The nanosheets showed higher resistance change in nonanal gas than that in carbon monoxide (CO), nitrogen dioxide (NO₂), acetone (CH₃COCH₃), hydrogen (H₂), ethanol (C₂H₆O), ammonia (NH₃), hydrogen sulfide (H₂S), formaldehyde (HCHO), acetaldehyde (CH₃CHO), or butanal (C₄H₈O). Crystal surfaces of the nanosheets would be effective for adsorption of nonanal molecules. Furthermore, it was shown that resistance changed with an increase in carbon number in aldehyde. The nanosheets had molecular selectivity for a series of aldehyde molecules. Molecular recognition of the nanosheets gave us a great advantage to detect nonanal gas which was produced by lung cancer.     

Darstellung,Konfigurationen und NMR-Daten der Säuren CH3(SR)  CHCOOH (R  C6H5, CH2C6H5, CH2COOH)

Preparation, Configurations and N.M.R. Dates of the Acids CH₃(SR)CHCOOH (R  C₆H₅, CH₂C₆H₅, CH₂COOH) The cis and trans isomers of the acids CH₃(SR)CHCOOH (R  C₆H₅, CH₂C₆H₅, CH₂COOH) were prepared by addition of HSR to CH₃CCCOOH in alkaline water solution and by alkaline hydrolysis of CH₃C(SR)₂CH₂COOC₂H₅ (R  C₆H₅, CH₂C₆H₅, CH₂COOC₂H₅). The oxidation products CH₃C(SO₂R)  CHCOOH (R  C₆H₅, CH₂COOH) were also prepared. The n.m.r. dates of the acids were obtained and some relations between them were discussed.     

Über die Konfiguration einiger durch Anlagerung von Mercaptoverbindungen an Acetylendicarbonsäure hergestellten Verbindungen

The Configuration of Some Compounds Prepared by Addition of Thiols to Acetylene Dicarboxylic Acid The acids RSC(COOH) = CHCOOH 3 with R = HOOCCH₂, HOOCCH(CH₃), C₆H₅, C₆H₅CH₂, p-ClC₆H₄CH₂ and C₆H₅CH(CH₃) have been prepared by addition of thiols RSH to acetylene dicarboxylic acid (alkali salt) in aqueous alkaline solution. It has been shown that only trans-isomers 3 and no cis-isomers 4 are formed. The methyl esters of 3 could be partially isomerized to yield the corresponding cis-esters. No cis-acids could be obtained by saponification of the latter.     

Structural characterization and thermal behaviour of block copolymers of polydimethylsiloxane and polyamide having trichlorogermyl pendant groups

Block copolymers having a pendant trichlorogermyl group as a part of polyamide segment? (CO? R′? CO? NH? Ar? NH? )_xCO? R′? CO? and polydimethylsiloxane of general formula [(? CO? R′? CO? HN? Ar? NH)_x? CO? R′? CO? NH(CH₂)₃SiO(CH₃)₂ ((CH₃)₂SiO)_ySi(CH₃)₂(CH₂)₃ NH? ]_n (where R′ = CH₂CH(GeCl₃), CH(CH₃)CH(GeCl₃), CH(GeCl₃)CH(CH₃); Ar = C₆H₄, (? C₆H₃? CH₃)₂, (? C₆H₃? OCH₃)₂, 2,5‐(CH₃)₂? C₆H₂, C₆H₄? O? C₆H₄) were prepared by a polycondensation reaction and characterized using CHN and Ge analysis, Fourier transform infrared (FTIR) and ¹H NMR spectroscopy, thermogravimetric analysis (TGA) and molecular weight determination. They have a lamellar structure with weight‐average molecular weight in the range 1.21 × 10⁵–4.79 × 10⁵ g mol^?1. These copolymers display two glass transition temperatures and have an average decomposition temperature of 489 °C. TGA, FTIR and gas chromatography/mass spectrometry studies indicate that degradation of these block copolymers results in carbon monoxide, oligomeric siloxanes and polyamide fragments. They are thermally stable due to the hydrogen bonded interlinked chains of polyamide, while they absorb water due to the presence of Ge? Cl bonding. Copyright © 2010 Society of Chemical Industry     

The ozone sensitized oxidative conversion of methane to methanol and ethane to ethanol

The reaction of O₂, O₃, and CH₄ or C₂H₆ of 7.76, 0.24 and 92% of the hydrocarbon respectively (residence time of 8.8 min) at 1 atm, and 400 °C for CH₄ and 300 °C for C₂H₆ gave CO, CO₂, H₂O, CH₂O and CH₃OH from CH₄ and in addition CH₄, C₂H₄, CH₃CHO and C₂H₅OH from C₂H₆. No reaction occurred when O₃ was absent indicating that the partial oxidation was sensitized (initiated) by the oxygen atoms formed by the decomposition of ozone.     

Effects of microwave,UV, and O3 on propylene gas degradation via photocatalytic reaction with CVD TiO2 films

A microwave/UV/ozone/TiO₂ photocatalyst hybrid process system, which is a combination of various propylene gas treatment techniques, is evaluated for use as an advanced, efficient technology for air pollution treatment. TiO₂ photocatalyst balls were prepared using low-pressure metal-organic chemical vapor deposition. The microwave/UV/TiO₂ photocatalyst hybrid process exhibited the higher degradation efficiency than the microwave/UV/alumina ball hybrid system. The degradation efficiency increased almost linearly with increasing ozone dose. The lower the propylene inlet concentration was the higher degradation efficiency. The double bond of propylene is broken by ozone and OH, resulting in production of CH₄ and C₂H₆. These two intermediate products are mineralized into CO₂, H₂O, and CO. C₂H₄ and C₃H₈ may be produced from CH₄, whereas C₂H₆ and C₃H₆ are produced by microwave irradiation.     

A one-step synthesis of protected functionalised titanocene dichlorides

We report a novel, high yield one-step synthesis of water stable and soluble titanocene dichloride dihydrochloride salts from the direct reaction of the neutral amino-substituted cyclopentadienes with TiCl₄. The following novel complexes have been synthesised: C₅H₄(CH₂)₂N(CH₂)₅]₂TiCl₂ (5), [C₅H₄CH(CH₂)₄NMe]₂TiCl₂ (6), [C₅H₄(CH₂)₂N(CH₂)₅]₂TiCl₂·2HCl (7), [C₅H₄CH(CH₂)₄]₂NMeTiCl₂·2HCl (8), [C₅H₄(CH₂)₂N(CH₂)₅]₂TiMe₂ (9).     

Detection of hazardous volatile organic compounds (VOCs) by metal oxide nanostructures-based gas sensors: A review

Since the sensing capability of semiconducting metal oxides was demonstrated in the 1960s, solid state gas sensors based on these materials have attracted considerable attention from both scientific and practical point of view. Because of the promising characteristics for detecting toxic gases and volatile organic compounds (VOCs) compared to conventional techniques, these devices are expected to play a key role in environmental monitoring, chemical process control, personal safety and so on in the near future. Therefore, in recent years, intensive studies have been conducted to improve their sensing performances, particularly to increase the sensitivity and detection limit of such devices. This can be accomplished by using metal oxide nanostructures with various shapes such as nanoparticles, nanowires, nanorods and nanotubes having sizes in the nanometer range. Owing to the high surface-to-volume ratios and consequently large number of surface sites exposed to target gas, nanostructured metal oxides enable a larger gas-sensing layer interaction and hence a higher sensitivity in comparison with conventional materials.This article extensively reviews recent developments in this field, focusing the attention on the detection of some common VOCs, including acetone (C₃H₆O), acetylene (C₂H₂), benzene (C₆H₆), cyclohexene (C₆H₁₀), ethanol (C₂H₅OH), formaldehyde (HCHO), n-butanol (C₄H₉OH), methanol (CH₃OH) toluene (C₇H₈), and 2-propanol (C₃H₈O), by means of conductometric solid state sensors based on nanostructured semiconducting metal oxides.     

Über die Konfigurationen und Konformationen einiger unsymmetrisch S-substituierter 2,3-Dimercaptobernsteinsäuren

The Configurations and Conformations of Some Unsymmetrical S-Substituted 2,3-Dimercapto Succinic Acids Some acids HOOCCH(SR)CH(SR′)COOH (R/R′ = HOOCCH₂, C₆H₅, C₆H₅CH₂ and p-ClC₆H₄CH₂, R ≠ R′) were prepared from HOOCC(SR)  CHCOOH and R′SH. Their configurations and conformations were discussed.     

C,N-chelated dicyclopentadienylzirconium complexes and their possible use as hydrogenation catalysts

In situ generated Cp₂Zr(n-Bu)Cl (6) reacts with {2-[(CH₃)₂NCH₂]C₆H₄}₂Pb to form exclusively {2-[(CH₃)₂NCH₂]C₆H₄}Cp₂ZrCl (7), [(CH₃)₂NCH₂]C₆H₅, butene and elemental lead. The further derivatization of chloride (7) to fluoride (8), hydride (9), methyl derivative (10), and a reduction of 7 are also described. The crystal structures of 7–10 were determined. The catalytic activity of 9 and 10 in hydrogenation of styrene was also preliminarily tested.     

Aqueous-Phase Processing of Bio-oil Model Compounds Over Pt–Re Supported on Carbon

The aqueous-phase processing (APP) of biomass-derived bio-oil model compounds such as ethanol, acetaldehyde, formic acid and acetic acid over Pt?CRe/C was examined. For the APP of ethanol at 250?°C, the product distribution was determined and quantified. H₂, CO₂, CH₄, C₂H₆, acetaldehyde, ethyl ether, ethyl acetate, acetic acid were found to be primary products and C₃H₈, methanol, butanol and acetal were found to be minor products. By also exploring the product distributions of acetaldehyde, acetic acid and formic acid under APP conditions with the Pt?CRe/C, the reaction network associated with the APP conversion of ethanol was determined. Using this reaction network, flux analysis was performed on the ethanol reaction system to determine the reaction pathway and relative rates (v₁?Cv₈) for each step. From this analysis, it was found that the dehydrogenation of the ethanol was the most active reaction in the reaction system.     

Poly-n-alkyl-methylsiloxane als effektive BPA-Punkt- und Stockpunkterniedriger für Mineralöle

Poly-n-alkyl-methylsiloxanes: Effective Cloud Point and Pour Point Depressants for Petroleum Distillates Linear poly-n-alkyl-methylsiloxanes of the formulae (CH₃)₃Si-[OSi(CH₃)R]_n-OSi(CH₃)₃ with R = C₁₂H₂₅, C₁₄H₂₉, C₁₆H₃₃ and n ⩽ 8 were prepared by various synthetic methods. Both these substances and the analogous cyclic siloxane derivates [OSi(CH₃)R]_m (m = 3…6) were found to be effective cloud point and pour point depressants for petroleum middle distillates. Some ideas concerning the mechanism of could point depression are discussed.     

Long-chain fatty acids containing ether linkage. I. The antibacterial and fungicidal activities of some new β-alkyloxypropionic acids and their methyl esters

β-Alkoxypropionic acids and their methyl esters were made with alkoxy groups ranging from C₄H₉O to C₁₈H₃₅O: R-O-CH₂CH₂COOH (CH₃). Methyl esters and acids were also made with one and with two oxyethylene groups between the alkoxy group and the propionic acid group: RO (CH₂ CH₂ O) n-CH₂CH₂ COOH(CH₃). The compounds were tested againstStaphylococcus aureus and againstPenicillium for growth inhibition. The optimum size of the alkoxy group appears to be R=C₁₂H₂₅. Oxyethylene groups enhanced the activity againstS. aureus, but had relatively little effect againstPenicillium.     

The role of protons in the NO reduction by acetylene over ZSM-5

Intermediate species formed on ZSM-5 zeolites during the selective catalytic reduction of NO by acetylene (C₂H₂-SCR) were investigated by transmittance FTIR and temperature-programmed desorption, to elucidate the different catalytic performance of the proton and sodium forms of ZSM-5. Bidentate nitrates formed exclusively on HZSM-5 were very active toward the reductant, whereas the nitrates associated with the Na⁺ ions on NaZSM-5 were inert. Although the saturation adsorption amount of acetylene on NaZSM-5 was about five times higher than that on HZSM-5 at 80 °C, most of the acetylene on NaZSM-5 was desorbed below 200 °C, whereas a considerable amount of acetylene was detected above 250 °C on HZSM-5 in TPD. The strongly adsorbed species formed on acetylene adsorption was vinyl alcohol (CH₂CHOH) bound to the Brønsted acid sites that could be converted to acetate species at elevated temperatures on HZSM-5. Based on our results, a mechanism of the C₂H₂-SCR on HZSM-5 was proposed in which the bidentate nitrates and acetate species formed exclusively on HZSM-5 react with each other, leading to NO_x elimination, which explains why the behavior of HZSM-5 is quite different from that of NaZSM-5 in the C₂H₂-SCR.     

Inhibition ofClostridium botulinum by aliphatic amines and long chain aliphatic aminodiamides

N-substituted aminodiamides of the general structure, RNHCO (CH₂)_x -CONH(CH₂)_yN(CH₃)₂, and the corresponding N-sulfopropyl derivatives were studied for their inhibiting effect on growth ofClostridium botulinum in culture media. With R = C₁₆H₃₃, more activity was observed with x = 2, 3, or 4 and y = 2, 3, or 4 than with R = C₁₂H₂₅ or C₁₀H₂₁ . There was little or no correlation of activity with the length of the x or y chains, but the addition of the sulfopropyl group resulted in decreased inhibitory activity. The C₃ to C₁₈ saturated aliphatic amines used for synthesizing the aminodiamides were effective inhibitors ofC. botulinum; tetradecyl-, pentadecyl-, and hexadecylamines were the most active with minimum inhibitory concentrations (MIC) of 0.8 μ/ml-The ratio of molecular weights of the diamides to the corresponding aliphatic amines indicated that most if not all of the inhibitory activity of the aminodiamides could be attributed to the amine moiety.     

Synthesis of di(methylphenyl)methane over heteropolyacids (H3PW12O40) catalysts

Catalytic synthesis of di(methylphenyl)methane (CH₃C₆H₄CH₂C₆H₄CH₃, DMPMs) from toluene and formaldehyde were investigated over various solids acids. At 140 °C and toluene/HCHO = 5/1, the conversion of HCHO over zeolite (Hβ, H-mordenite, HX, HY and HZSM-5) is limited, while heteropolyacids (H₃PW₁₂O₄₀, H₄SiW₁₂O₄₀ and H₃PMo₁₂O₄₀) exhibited higher activity and DMPMs selectivity. The best yield of DMPMs reached 81.5% (conversion of HCHO nearly 100%). H₃PW₁₂O₄₀ could be recovered by simply drying and the recycle-used catalyst remained its activity and structure in five runs.     

Adsorptive and stripping behavior of methylene blue at gold electrodes in the presence of cationic gemini surfactants

The adsorptive and stripping behavior of methylene blue (i.e. methylene blue chloride, MB) at a gold electrode has been studied with voltammetry, alternating current impedance spectra (ACIS) and quartz crystal microbalance (QCM). MB exhibits a pair of cyclic voltammetry peaks at about −0.3 V (versus SCE) in 0.05 M pH 6.9 phosphate buffer solutions. In the presence of cationic gemini surfactants such as C₁₆H₃₃N(CH₃)₂-C₄H₈-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₄-C₁₆), C₁₆H₃₃N(CH₃)₂-C₄H₇OH-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₄OH-C₁₆), C₁₆H₃₃N(CH₃)₂-CH₂-C₆H₄-CH₂-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-ph-C₁₆) and C₁₆H₃₃N(CH₃)₂-C₁₂H₂₄-N(CH₃)₂C₁₆H₃₃Br₂ (C₁₆-C₁₂-C₁₆), the anodic peak grows rapidly and moves in positive direction, but the cathodic peak gradually decreases, due to the association adsorption and electrostatic interaction of the geminis with MB and its reduced product (i.e. leuko methylene blue, LMB). With the aid of geminis the adsorption amount of MB increases under open-circuit, but the impedance of the mixed adsorption film to Fe(CN)₆^3−/4− almost keeps unchanged, compared with either bare gold electrodes or MB film, while the adsorption film of geminis exhibits greater impedance. This probably is due to the electron medium action of MB in the film. Gemini surfactants with same alkyl-chain (i.e. -(CH₂)₁₅CH₃) but different molecular structure, exhibit different influence. The enhancing action of geminis studied follows such order as: C₁₆-ph-C₁₆ > C₁₆-C₄-C₁₆ > C₁₆-C₄OH-C₁₆ > C₁₆-C₁₂-C₁₆. The change of peak potential was ascribed to the interaction between MB and surfactants, as well as the blocking action of surfactant film. For comparison, the influence of dihexadecyldimethylammonium bromide (DCAB) and cetyltrimethylammonium bromide (CTAB) was studied, and the influence of other factors is discussed as well.     

Preparation of a new type of half-sandwich (alkoxylalkylcyclopentadienyl)titanium trichloride complex and X-ray structural characterization of (CH3OCH2CH(CH3)C5H4)TiCl3

New substituted alkoxylalkylcyclopentadienyl titanium trichloride complexes, CH₃OCH₂CH(CH₃)C₅H₄TiCl₃ (3), CH₃OCH(CH₃)CH₂C₅H₄TiCl₃ (4) and CH₃OCH₂CH₂CH₂C₅H₄TiCl₃ (5) have been synthesized and 3 has been studied by X-ray diffraction. The crystal structure of 3 shows that there is an intramolecular coordination between the ethereal oxygen atom in the side chain on the Cp ring and the titanium atom with an average Ti–O bond length of 2.24 Å. Due to steric limitation around the coordination sphere of titanium, the oxygen atoms in the side chain in complexes 4 and 5 do not coordinate with the central metals.     

Synthesis of (C5H5)2Zr(O2C)CH3 and (C5H5)2Zr(O2C)CH2CH3 for olefin polymerization

Summary (C₅H₅)₂Zr(O₂C)CH₃ and (C₅H₅)₂Zr(O₂C)CH₂CH₃ complexes were synthesized, characterized and activated with MAO for ethylene polymerization. The highest catalytic activity was achieved at Al/Zr molar ratio of 3000 for both systems. The effects of the size of the R group in the carboxylate ligands, the Al/Zr molar ratio and reaction temperature on the catalytic activity and polymer properties were studied and discussed.