Determination of Vapor Pressures Using Extrapolation of Adjusted Retention Times

Vapor pressure is one of the fundamental properties which govern the distribution of organic compounds in the environment. This property is estimated for five series of homologous substituted alkanes of the type H—(CH₂)_n—Y, where Y denotes Cl, Br, CHO, COOCH₃, OCOCH₃ and n varies from 5 to 14 using extrapolation of adjusted retention times to 25 °C. The results are compared with those obtained by using indirect methods for 40 compounds and a significant improvement is obtained. Indeed, the absolute average error percentage for the same series does not exceed 2.6%     

A Novel Synthetic Route to Furan-Lignans

Three naturally occurring furan–lignans and two analogs have been synthesized by a short and efficient route starting from the corresponding aryl acid. The selective reductive removal of allylic hydroxy by palladium oxide in a mixed solvent of THF–CHCl₃ was employed as the key step.     

Spectres 13C-nmr de Quelques Glutarimides Substitues en α et en β

Abstract

¹³C-nmr spectra of α and β glutarimides have been determined and analyzed. Assignments related to the imidocarbonyls are discussed.     

Enhancement of the Fluorimetric Properties of Some Carboxyl Substituted Anthracenes by Complexation with Bovine Serum Albumin

Abstract

A study has been conducted of the fluorimetric properties of substituted anthracenes, following complexation with bovine serum albuinin(BSA). It was found that although protein binding of the ligands enhances their fluorimetric properties, it fails to do so for their phosphorimetric properties. BSA would serve well in post column reactors for HPLC detectors, but not in pre-column systems.     

β-取代苯(氧)丙烯酸酯(酰胺)类化合物的合成及其杀菌活性的研究

合成了 2 2个 β-芳氧乙氧基丙烯酸酯类和 8个 β-甲氧基 - α-邻甲苯氧基丙烯酰胺类化合物 .生物测定表明 ,这些化合物对黄瓜灰霉病有一定杀菌活性 ,对不同抗性菌的抑制有一定规律 .     

The effect of ‘crystallinity’ and structural disorder on the electrochemical performance of substituted nickel hydroxide electrodes

β_bc-Nickel hydroxide exhibit non-uniform broadening reflections in their PXRD pattern due to the presence of structural disorder. β_bc-Nickel hydroxide electrodes with smaller crystallite size and structural disorder reversibly exchanges 0.9e/Ni. Co/Zn/Ca/Cd-substituted β_bc-nickel hydroxide samples also display non-uniform broadening of reflections in their powder X-ray diffraction patterns with smaller crystallite size and exchanges 0.7–0.8e/Ni. Hydrothermal treatment of β_bc-nickel hydroxide slurry at 170 °C results in an ordering of reflections in their powder X-ray diffraction pattern with an increased crystallite size. Crystalline β-nickel hydroxide electrode reversibly exchanges 0.3–0.4e/Ni. Hydrothermal-treated Co/Zn/Ca/Cd-substituted β_bc-nickel hydroxide slurries at 170 °C display sharp reflections with similar crystallite size and electrochemical activities as that of crystalline β-nickel hydroxide. This clearly demonstrates that partial substitution of Co/Zn/Ca/Cd in the nickel hydroxide matrix does not show any dramatic improvement in their electrochemical activity at 25–30 °C. Structural disordered material with smaller crystallite size delivers electrochemical activity close to theoretical capacity.     

Synthesis of new materials based on polythiophenes substituted with mesogen groups

A new family of conjugated polymers formed by 3-alkyloximethylthiophenes substituted with a biphenyl group was synthesised by a route involving first the coupling of a functionalised alkyl chain, from 8 to 12 carbon atoms, to 3-methanolthiophene, and then the attachment of the mesogen group. The monomer was characterised by conventional techniques, and thermal studies were also achieved. The polymerisation of these units was carried out via oxidative polymerisation with FeCl₃. The resultant polymers were characterised by FT-IR, elemental microanalysis and XPS. Subsequently, these materials were doped with I₂ and characterised by the above techniques and conductivity measurements, which indicated that these materials are in the semiconductor range. The polymerisation of these monomers was also carried out via electrochemical methods, and it was found that, together with the oxidation of the thiophene ring, the oxidation of the biphenyl group is also produced, for which an over-oxidised material is obtained, as demonstrated by XPS analysis and theoretical calculations.     

Highly selective substitutions in 2,3-dichloropyrazine. A novel general approach to aloisines

A highly efficient synthesis of the potent CDKs (cyclin-dependent kinases) inhibitors, aloisines (substituted 5H-pyrrolo[2,3-b]pyrazines) is presented. The method is based on highly selective monosubstitution of a single chlorine atom in 2,3-dichloropyrazine with lithiated ketones, esters, and nitriles followed by co-cyclization of the resulting intermediates with primary amines or hydrazines.     

Synthesis,anti-tuberculosis activity and QSAR study of 2,4-diarylquinolines and analogous polycyclic derivatives

The multicomponent syntheses of 2,4-di-aryl-quinolines and analogous polycyclic derivatives as anti-tuberculosis agents were described. They were prepared via Beyer and Friedländer methods under microwave irradiation in short reaction times and good yields. Several homogeneous and heterogeneous acid catalysts were compared for preparing 2,4-di-arylquinolines and among them trifluoroacetic acid (TFA) reached the higher yields. Two derivatives exhibited activity against Mycobacterium tuberculosis H37Rv (Mtb), underwent additional testing and were considered lead compounds. The synthesis of a series of polycyclic analogous led to six new active compounds and a Quantitative Structure Activity Relationship study (QSAR) study was established.