Potassium N‐(6‐oxo­cyclo­hexa‐1,3‐dien‐5‐yl­idene­methyl)­glycinate

We are very interested in characterizing ligands derived from salicyl­aldehyde and α‐amino acids. These ligands form interesting complexes with different transition metals, which are very useful for understanding some biological systems. For Schiff bases derived from salicyl­aldehyde and different alkyl­amines or aryl­amines, the enol–imine form is predominant. The title compound, (I), shows bond distances which are clearly in agreement with the keto–amine form.     

Dérivés lithiés et cuprolithiés du décachlorobiphényle

Exchange between decachlorobiphenyl and n-butyllithium leads to lithium derivatives. Hydrolysis affords octa- and nonachlorobiphenyls. Reaction with CuI yields aryllithium cuprates which react with acid chlorides to give the corresponding ketones.     

Remote Oxygen and Nitrogen Plasma Inactivation of <Emphasis Type="Italic">Staphylococcus</Emphasis><Emphasis Type="Italic">aureus</Emphasis>: Effects and Mechanisms

The distribution of active species in remote oxygen and nitrogen plasma and the germicidal effect (GE) of Staphylococcus aureus on the surface of medical poly(tetrafluoroethylene), polyvinyl chloride and polyethylene terephthalate films, which had been widely used in medical devices, were studied. The results showed that the concentration of electrons and ions decreased rapidly with increasing the distance from the center of induction coil, which approximated to 0 at 40 cm, whereas the concentration of both oxygen and nitrogen radicals reduced slowly, which decreased 20% within 40 cm. Fast etching action on cell membrane by electrons, ions and radicals are primary reasons of oxygen and nitrogen plasma inactivation, which leads to the cellular contents effuse and engender bacteria death, however, the GE of UV radiation in remote plasma is feebleness comparatively. The GE also depends on the oxidation of gas for discharge and the surface characters of material.     

Sprachverwirrung bei Gefahrgütern. Gefahrgut‐Informations‐ und ‐kommunikationssysteme

In the dangerous goods regulations there is no clear rule for the naming of dangerous goods which are not directly registered in the dangerous goods list. The use of different names for the same substances makes communication about these goods difficult. On the other hand, many chemical names include special characters (e.g. Greek letters, umlauts etc.) which are not easily transferable electronically. This results in a potential for substantial error in the case of an incident with dangerous goods. To solve this problem a database is recommended with uniform names which are easily transferable electronically.     

Synthesis and Reactions of 1‐Amino‐5‐morpholin‐4‐yl‐6,7,8,9‐tetrahydrothieno[2,3‐c]isoquinoline

The pyrazolone derivative 4 was synthesized by reaction of carbohydrazide 2 with ethyl benzoylacetate in ethanol and p‐toluene sulphonic acid followed by cyclization upon heating in acetic acid. Chloroacylation of amino ester and amino benzoyl compounds 1 , 19 gave the chloro acetylamino derivatives 5 and 20 respectively which both of them react with different amines to afford compounds 6 , 23a‐d . Hydrolysis and decarboxlation of compound 1 yielded the aminothienotetrahydroisoquinoline 8 which was used as versatile material for synthesizing other heterocyclic compounds 9‐18 . Compound 20 react with hexamethylenetetramine and malononitrile yielded thediazepino and pyrrolo derivatives 21 , 22 respectively.     

Regioselective Photocyclization Reactions of 3‐Allyloxy‐6‐chloro‐2‐(thiophen‐3‐yl)‐4H‐chromen‐4‐one: Solvent Effect

The photo‐irradiation of thienylchromenone resulted in the regioselective cyclization which is exclusively controlled by the nature of solvent used as reaction medium. Compared to nonpolar medium, polar solvent furnished a diverse array of novel angular tetracyclic photoproducts with gem‐dihydro functionality and exocyclic double bonds on the fused pyran ring, which is unprecedented to best of our knowledge.     

Thermal expansion of MNbO<Subscript>4</Subscript> phases where <Emphasis Type="Italic">M</Emphasis>=Al,Cr, Fe,Ga

Studies on thermal expansion of the MNbO₄ type phases where M=Al, Cr, Fe, Ga have been carried out in the high-temperature X-ray diffraction attachment. In the case of isotypic AlNbO₄ and GaNbO4 compounds the structure of which consists of the ReO₃ type blocks, the direction of minimal thermal expansion is consistent with the direction in which these blocks spread to infinity. In the case of CrNbO₄, the maximal thermal expansion direction is consistent with the [001] direction parallel to which the edge shared octahedra building its structure form infinite chains. FeNbO₄ has the highest coefficients of thermal expansion in this group of compounds.     

1,17‐Hepta­decane­diol

In the title compound, C₁₇H₃₆O₂, one of the hydroxyl groups has a gauche conformation with respect to the hydro­carbon skeleton, which is all‐trans, whereas the other has a trans conformation. The molecular shape is rod‐like and the compound has a rotator phase in which mol­ecules are assured greater motional freedom, as in liquid crystals. In addition, the mol­ecules arranged along the longest axis, b, form layers which are very similar to those of the smectic A liquid crystals.     

Synthèse de composés comportant deux hétérocycles oxygénés accoles au noyau benzénique, éthers du résorcinol

We wish to report the preparation of new bisheterocyclic compounds derived from resoreinol. We tried to sue methods during this investigation which would be selective and afford only tricyclic linear compounds. The starting material was resorcinol or the monomethylether of resorcinol. By reaction with chloroacetonitrile, acrylonitrile or ethyl chlorobutanoate, we obtained the intermediate compounds which were then cyclized by reaction with sodium acetate or polyphosphoric acid; either a catalytic reduction or treatment with zinc in presence of hydrochloric acid furnished the heterocyclic base. Another condensation followed by a cyclization and a reduction gave the desired compounds.     

Neue molekulare Indium‐Zinn‐Sauerstoff‐ und Indium‐Zinn‐Natrium‐Sauerstoff‐Chlor‐Cluster

Abstract. The five‐membered heteroelement cluster THF · Cl₂In(O^tBu)₃Sn reacts with the sodium stannate [Na(O^tBu)₃Sn]₂ to produce either the new oxo‐centered alkoxo cluster ClInO[Sn(O^tBu)₂]₃ ( 1 ) (in low yield) or the heteroleptic alkoxo cluster Sn(O^tBu)₃InCl₃Na[Sn(O^tBu)₂]₂ ( 2 ). X‐ray diffraction analyses reveal that in compound 1 the polycyclic entity is made of three tin atoms which together with a central oxygen atom form a trigonal, almost planar triangle, perpendicular to which a further indium atom is connected through the oxygen atom. The metal atoms thus are arranged in a Sn₃In pyramid, the edges of which are all saturated by bridging tert‐butoxy groups. The indium atom has a further chloride ligand. Compound 2 has two trigonal bipyramids as building blocks which are fused together at a six coordinate indium atom. One of the bipyramids is of the type SnO₃In with tert‐butyl groups on the oxygen atoms, while the other has the composition InCl₃Na with chlorine atoms connecting the two metals. The sodium atom in 2 has further contacts to two plus one alkoxide groups which are part of a[Sn(O^tBu)₂]₂ dimer disposing of a Sn₂O₂ central cycle. The hetero element cluster in 2 thus combines three closed entities and its skeleton SnO₃InCl₃NaO₂Sn₂O₂ consists of three different metallic and two different non‐metallic elements.     

Formation and thermal properties of nanocrystalline Bi<Subscript>4</Subscript>Ti<Subscript>3</Subscript>O<Subscript>12</Subscript>

Mechanism by which nanocrystalline Bi₄Ti₃O₁₂ is formed in thermal treatment of coprecipitated hydroxides was studied. It was shown that the onset of the active formation is correlated with the melting point of the surface phase based on bismuth oxide. The technological synthesis parameters of Bi₄Ti₃O₁₂, at which crystallite sizes in the range 35–60 nm are provided, were determined.     

Solvated and solvent‐free forms of N,N′‐di­thio­diphthal­imide

N,N′‐Di­thio­diphthal­imide, C₁₆H₈N₂O₄S₂, crystallizes from ethyl acetate with two independent mol­ecules in the asymmetric unit, in which the N—S—S—N torsion angles are ?83.59 (19) and 92.9 (2)°. The mol­ecules are linked by C—H?O hydrogen bonds and aromatic π–π‐stacking interactions into a three‐dimensional framework. When crystallized from either di­chloro­methane or ethanol, solvates are formed in which the mol­ecules of the title compound lie across twofold rotation axes in space group C2/c, with N—S—S—N torsion angles of 93.54 (7) and 96.14 (11)°. There are no hydrogen bonds in these solvates, but the mol­ecules are linked by aromatic π–π‐stacking interactions into chains, between which there are continuous channels. Disordered solvent mol­ecules occupy these channels, which account for ca 20% of the unit‐cell volume.     

Nanocrystallization of hydrogen-charged Mg<Subscript>76</Subscript>Ni<Subscript>19</Subscript>Y<Subscript>5</Subscript> amorphous alloy

The crystallization of a hydrogen-charged melt-spun Mg₇₆Ni₁₉Y₅ amorphous alloy was studied in order to understand the influence of hydrogen absorbed on the crystallization kinetics and mechanism. Hydrogenation does not affect the thermal stability, but decreases significantly the enthalpy of crystallization. The glass transition, which is well manifested in the hydrogen-free alloy, is not observed after hydrogen charging. The main crystalline phases in the H-free and H-charged alloys are the same after complete transformation, but with finer microstructure for the hydrogenated samples.Analysis of the crystallization kinetics reveals that during annealing of hydrogen charged Mg₇₆Ni₁₉Y₅ growth of nanocrystals surrounded by amorphous phase takes place just in the beginning of the transformation, followed by grain growth in fully crystallized material, which is the main process.This revised version was published online in November 2005 with corrections to the Cover Date.     

4‐Hydro­xy‐ONN‐azoxy­benzene

The oxidation of 4‐hydroxy­azo­benzene provided a mixture of two azoxy compounds, which were separated by column chromatography. The isomer with the higher melting point appeared to belong to the α (ONN) series, as determined by X‐ray diffraction. The mol­ecule, C₁₂H₁₀N₂O₂, is almost planar. The benzene rings are twisted by 11.7 (2) (substituted) and 4.1 (1)° (unsubstituted) with respect to the ONN plane. The mol­ecules are connected to one another by strong O—H?O hydrogen bonds forming chains extended along [001], which are bound by much weaker C—H?O hydrogen bonds forming layers in the bc plane.     

Specific Binding of Anionic Porphyrin and Phthalocyanine to the G-Quadruplex with a Variety of <em>i</em><em>n Vitro</em> and<em> </em><em>i</em><em>n Vivo</em> Applications

The G-quadruplex, a four-stranded DNA structure with stacked guanine tetrads (G-quartets), has recently been attracting attention because of its critical roles in vitro and in vivo. In particular, the G-quadruplex functions as ligands for metal ions and aptamers for various molecules. Interestingly, the G-quadruplex can show peroxidase-like activity with an anionic porphyrin, iron (III) protoporphyrin IX (hemin). Importantly, hemin binds to G-quadruplexes with high selectivity over single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), which is attributable to an electrostatic repulsion of phosphate groups in ssDNA and dsDNA. The G-quadruplex and hemin-G-quadruplex complex allow development of sensing techniques to detect DNA, metal ions and proteins. In addition to hemin, anionic phthalocyanines also bind to the G-quadruplex formed by human telomere DNA, specifically over ssDNA and dsDNA. Since the binding of anionic phthalocyanines to the G-quadruplex causes an inhibition of telomerase activity, which plays a role in the immortal growth of cancer cells, anionic phthalocyanines are promising as novel anticancer drug candidates. This review focuses on the specific binding of hemin and anionic phthalocyanines to G-quadruplexes and the applications in vitro and in vivo of this binding property.     

Di‐tert‐butyl ketone hydrazone and di‐tert‐butyl ketone triphenyl­phosphoranyl­idene­hydrazone

Reaction of di‐tert‐butyl ketone with hydrazine hydrate gives di‐tert‐butyl ketone hydrazone, C₉H₂₀N₂, which is dimerized by double hydrogen bonding in the solid state. Further reaction of this compound with dibromo­triphenyl­phospho­rane gives di‐tert‐butyl ketone triphenyl­phosphoranyl­idene­hydrazone, C₂₇H₃₃N₂P, in the structure of which double chains parallel to the c axis are formed through weak C—H⋯π and π–π stacking inter­actions. The hydrazone group is nearly planar in both cases. In the second compound, one of the aromatic rings is nearly coplanar with the hydrazone moiety, indicating possible π‐conjugation.     

Energetic ion bombardment of Ag surfaces by C<Stack><Subscript>60</Subscript><Superscript>+</Superscript></Stack> and Ga<Superscript>+</Superscript> projectiles

The ion bombardment-induced release of particles from a metal surface is investigated using energetic fullerene cluster ions as projectiles. The total sputter yield as well as partial yields of neutral and charged monomers and clusters leaving the surface are measured and compared with corresponding data obtained with atomic projectile ions of similar impact kinetic energy. It is found that all yields are enhanced by about one order of magnitude under bombardment with the C60+ cluster projectiles compared with Ga+ ions. In contrast, the electronic excitation processes determining the secondary ion formation probability are unaffected. The kinetic energy spectra of sputtered particles exhibit characteristic differences which reflect the largely different nature of the sputtering process for both types of projectiles. In particular, it is found that under C60+ impact (1) the energy spectrum of sputtered atoms peaks at significantly lower kinetic energies than for Ga+ bombardment and (2) the velocity spectra of monomers and dimers are virtually identical, a finding which is in pronounced contrast to all published data obtained for atomic projectiles. The experimental findings are in reasonable agreement with recent molecular dynamics simulations.     

2,3,4,6‐Tetra‐O‐acetyl‐α‐d‐glucopyranosyl azide

The Cu^I‐catalysed 1,3‐dipolar cycloaddition of an azide and a terminal alkyne is becoming an increasingly popular tool for synthetic chemists. This is the most representative of the so‐called `click reactions' and it is used to generate 1,4‐disubstituted triazoles in high yield. During studies on such cycloaddition reactions, a reduced reactivity of an α‐glucosyl azide with respect to the corresponding β‐anomer was observed. With the aim of understanding this phenomenon, the structure of the title compound, C₁₄H₁₉N₃O₉, has been determined at 140 K. The glucopyranosyl ring appears in a regular ⁴C₁ chair conformation with all the substituents in equatorial positions, except for the anomeric azide group, which adopts an axial orientation. The observed bond lengths are consistent with a strong anomeric effect, which is reflected in a change in dipolar character and hence reduced reactivity of the α‐glucosyl azide.     

Green synthesis of ZnCo<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoparticles by <Emphasis Type="Italic">Aloe albiflora</Emphasis> extract and its application as catalyst on the thermal decomposition of ammonium perchlorate

This work aimed the evaluation of pH influence in the obtainment of composites from palygorskite (PAL) and chitosan (CS). The materials PAL/CS-1 and PAL/CS-2 were obtained by similar methodology with modified pHs: 5.0 ± 0.5 and 11.0 ± 0.5, respectively. Both materials were evaluated for specific surface area analysis, elemental analysis, XRD, FTIR, thermal analysis, MEV and interaction drug composite, using 5-aminosalicylic acid (5-ASA) as model. The surface area analysis data showed the reduction in PAL/CS-2 related to CS presence on surface in contrast with PAL/CS-1, which corroborate with elemental analysis present nine times more of CS in PAL/CS-2 composition. Regarding to XRD data, the interaction of CS with PAL did not cause modification in clay structure in PAL/CS-2. These results were confirmed by FTIR data with the N–H deformation vibration in PAL/CS-2 while PAL/CS-1 was invariable to PAL. In thermal analysis, results were observed 60.2% residual mass to PAL/CS-2, which it was lower than PAL (87.2%) and PAL/CS-1 (86.7%), due to CS decomposition which had enthalpy energy of 62.1 J g^?1 K^?1, confirming the data previously cited. PAL/CS-2 presented 5-ASA adsorption of 7.9 mg g^?1, which was inferior to others probably caused by scarcity of active sites of PAL already occupied by CS. These results showed that pH control was fundamental to enhance efficiency of obtainment of composite in basic pH because the decrease in CS protonation degree increasing interaction between this one and PAL, although it contributed to decrease in 5-ASA adsorption due to low availability of interaction sites.     

Exploration of high pressure phase in LaGaO<Subscript>3</Subscript> and LaCrO<Subscript>3</Subscript>

Summary Structural phase transitions upon the application of high pressure in LaGaO₃ and LaCrO₃, which were prospected from diffraction and thermal analyses of phase transition under ambient pressure, were discovered by using high-pressure X-ray diffraction. It was revealed that the crystal structures of LaCrO₃ and LaGaO₃ changed completely from that of orthorhombic distorted perovskite to that of a rhombohedral distorted one upon the application of pressure higher than 5.4 and 3.0 GPa, respectively, at room temperature. The variation of lattice constants with pressure was investigated for the high-pressure rhombohedral phases of LaCrO₃ and LaGaO₃ and isothermal compressibility was estimated. The variation of lattice constants with pressure at room temperature in the high-pressure rhombohedral phase was compared with that with temperature at ambient pressure in high-temperature rhombohedral phase. It was found that the application of pressure decreased the crystal symmetry, which was opposite to the result in the case of increasing the temperature.