Chloro(η6‐p‐cymene)(2‐methyl‐5‐oxo‐7‐phenyl‐5,6‐di­hydro‐2H‐1,2,4‐triaz­epine‐3‐thiol­ato‐κ2N4,S)­ruthenium(II)

The novel title ruthenium(II) complex, [RuCl(C₁₀H₁₄)(C₁₀H₁₀N₃OS)], was synthesized from the reaction of 1,2,4‐triazepine, a new class of bidentate ligands, with [Ru(p‐cymene)Cl₂]₂. The 1,2,4‐triazepine ligand is coordinated to the metal centre through the N‐4 and S atoms, forming a four‐membered chelate ring. This is the first structural example of a transition metal complex containing a 1,2,4‐triazepine ligand.     

Antitumor,cytotoxic, and antioxidant evaluation of six heterocyclic compounds containing different heterocycle moieties

Heterocyclic compounds with different heterocycle moieties, namely benzoxazinone, benzimidazole, quinazolinone, and benzofuranone heterocyclic rings, were synthesized, characterized, and evaluated for their anticancer activity against human hepatocellular carcinoma cell line (HepG2) using sulforhodamine B (SRB) and dimethylthiazol-diphenyltetrazolium bromide (MTT) assays. Also, their cytotoxic activities were tested against human epithelioid carcinoma (Hela) cell line in comparison with normal cell, amniotic epithelial (WISH) cell line, as an in vitro toxicity estimation model. The results showed clearly that 2-(2-benzyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide 4 is the most potent antioxidant and anticancer agents. Although, 3-amino-2-benzylquinazolin-4(3H)-one 5 is less potent anticancer agent against Hela but it is more safe against normal cell (WISH).     

Thermal convection around obstacles: the case of Sierpinski carpets

Measurements of free convection velocity profiles by laser Doppler velocimetry in a cavity containing Plexiglas reconstructed Sierpinski carpets are compared with computed profiles using the SIMPLER numerical code applied to the Navier–Stokes equations. This first step validates the numerical code into which two thermal conductivities are used (that of the liquid and that of the solid), together with two viscosities (that of the liquid and a fictitious high viscosity of the order of 10³⁰ for the solid). Next, the code is used for a network of Sierpinski carpets, allowing the evaluation of a seepage velocity from the Navier–Stokes equations.     

Synthesis of New Tetraheterocyclic Systems by the Mixed Condensation Reactions on [1,2,4]Triazolo[4,3‐a][1,5]benzodiazepines

We report here a one step synthesis of a new series of bis‐[1,2,4‐triazolo][4,3‐a:3′,4′‐d][1,5]benzodiazepines 3a–e and [1,2,4]oxadiazolo[5,4‐d][1,2,4]triazolo[4,3‐a][1,5]benzodiazepines 5a–c by the condensation reactions of diarylnitrilimines and arylonitrile oxides. This 1,3‐dipolar cycloaddition is completely regioselective. The structure of these products has been confirmed by ¹H, ¹³C NMR and mass spectroscopic.     

Local atomic structures of single-component metallic glasses

In this study we examine the structural properties of single-component metallic glasses of aluminum. We use a molecular dynamics simulation based on semi-empirical many-body potential, derived from the embedded atom method (EAM). The radial distribution function (RDF), common neighbors analysis method (CNA), coordination number analysis (CN) and Voronoi tessellation are used to characterize the metal’s local structure during the heating and cooling (quenching). The simulation results reveal that the melting temperature depends on the heating rate. In addition, atomic visualization shows that the structure of aluminum after fast quenching is in a glassy state, confirmed quantitatively by the splitting of the second peak of the radial distribution function, and by the appearance of icosahedral clusters observed via CNA technique. On the other hand, the Wendt-Abraham parameters are calculated to determine the glass transition temperature (T_g), which depends strongly on the cooling rate; it increases while the cooling rate increases. On the basis of CN analysis and Voronoi tessellation, we demonstrate that the transition from the Al liquid to glassy state is mainly due to the formation of distorted and perfect icosahedral clusters.     

Structural and textural features of TiO<Subscript>2</Subscript>/SAPO-34 nanocomposite prepared by the sol–gel method

This paper focuses on the synthesis of nanocomposite materials, TiO₂/SAPO-34, using the sol–gel method, which involves preparing a mixture between as-synthesized or calcined SAPO-34 zeolite and TiO₂ gel under hydrothermal crystallization and then calcining it at 400 °C for the formation of the TiO₂ anatase phase. The structural and textural features of the obtained materials were determined by various physico-chemical techniques such as thermogravimetric analysis, X-ray diffraction, scanning electronic microscopy, nitrogen sorption at 77 K, energy dispersive X-ray analysis and ultraviolet–visible spectrometry. The DRX results showed that calcination at 400 °C of the mixture between the calcined SAPO-34 and TiO₂ gel led to the collapse of the original framework of zeolite, but formed the anatase TiO₂ in a nano-spherical morphology; however, the use of as-synthesized SAPO-34 supports provides a mixture phase between SAPO-34 and TiO₂ anatase after calcination. The photocatalytic properties of the SAPO-34/TiO₂ and TiO₂-type materials were tested for the removal of methylene blue (MB) dye. The MB degradation proved to increase as a function of contact time, catalyst mass and the initial concentration of MB.     

From molecular to macroscopic engineering: shaping hydrogen-bonded organic nanomaterials

The self‐assembly and self‐organization behavior of chromophoric acetylenic scaffolds bearing 2,6‐bis(acetylamino)pyridine ( 1 , 2 ) or uracyl‐type ( 3 – 9 ) terminal groups has been investigated by photophysical and microscopic methods. Systematic absorption and luminescence studies show that 1 and 2 , thanks to a combination of solvophilic/solvophobic forces and π–π stacking interactions, undergo self‐organization in apolar solvents (i.e., cyclohexane) and form spherical nanoparticles, as evidenced by wide‐field optical microscopy, TEM, and AFM analysis. For the longer molecular module, 2 , a more uniform size distribution is found (80–200 nm) compared to 1 (20–1000 nm). Temperature scans in the range 283–353 K show that the self‐organized nanoparticles are reversibly formed and destroyed, being stable at lower temperatures. Molecular modules 1 and 2 were then thoroughly mixed with the complementary triply hydrogen‐bonding units 3 – 9 . Depending on the specific geometrical structure of 3 – 9 , different nanostructures are evidenced by microscopic investigations. Combination of modules 1 or 2 with 3 , which bears only one terminal uracyl unit, leads to the formation of vesicular structures; instead, when 1 is combined with bis‐uracyl derivative 4 or 5 , a structural evolution from nanoparticles to nanowires is observed. The length of the wires obtained by mixing 1 and 4 or 1 and 5 can be controlled by addition of 3 , which prompts transformation of the wires into shorter rods. The replacement of linear system 5 with the related angular modules 6 and 7 enables formation of helical nanostructures, unambiguously evidenced by AFM. Finally, thermally induced self‐assembly was studied in parallel with modules 8 and 9 , in which the uracyl recognition sites are protected with tert‐butyloxycarbonyl (BOC) groups. This strategy allows further control of the self‐assembly/self‐organization process by temperature, since the BOC group is completely removed on heating. Microscopy studies show that the BOC‐protected ditopic modules 8 self‐assemble and self‐organize with 1 into ordered linear nanostructures, whereas BOC‐protected tritopic system 9 gives rise to extended domains of circular nano‐objects in combination with 1 .