Photoproduction of iodine with nanoparticulate semiconductors and insulators

The crystal structures of different forms of TiO2 and those of BaTiO3, ZnO, SnO2, WO3, CuO, Fe2O3, Fe3O4, ZrO2 and Al2O3 nanoparticles have been deduced by powder X-ray diffraction. Their optical edges have been obtained by UV-visible diffuse reflectance spectra. The photocatalytic activities of these oxides and also those of SiO2 and SiO2 porous to oxidize iodide ion have been determined and compared. The relationships between the photocatalytic activities of the studied oxides and the illumination time, wavelength of illumination, concentration of iodide ion, airflow rate, photon flux, pH, etc., have been obtained. Use of acetonitrile as medium favors the photogeneration of iodine.     

A high‐pressure single‐crystal synchrotron diffraction study of NH4RbTe4O9·2H2O: stability of three different TeOx coordination polyhedra

The crystal structure of ammonium rubidium nonaoxotetratellurate(IV) dihydrate has been studied as a function of pressure up to 7.40 GPa. The ambient‐pressure structure is characterized by the co‐existence of three different Te—O polyhedra (TeO₃, TeO₄ and TeO₅), which are connected to form layers. NH₄⁺, H₂O and Rb⁺ are incorporated between the layers. Both the Rb1 position, which is located on a twofold axis, and the Rb2 position are partially occupied. The three different types of coordination polyhedra around Te⁴⁺ are stable up to at least 5.05 GPa. No phase transition is observed. The fit of the unit‐cell volume as a function of pressure gives a zero‐pressure bulk modulus of 34 (1) GPa with a zero‐pressure volume of V₀ = 2620 (4) ų [B′ = 1.4 (2)].     

A Convenient Method of Synthesis of Bis-Indolylmethanes: Indium Trichloride Catalyzed Reactions of Indole with Aldehydes and Schiff's Bases

Anhydrous indium trichloride (InCl₃) is found to catalyze the electrophilic substitution reaction of indole with aromatic aldehydes and Schiff's bases which resulted in an efficient synthesis of bis-indolylmethanes in good to excellent yield.     

Microwave Assisted One Pot Synthesis of Substituted 3-Formyl Benzoates Using Vilsmeier Reagent

A facile one pot conversion of alkyl diacylacetates to 2,6-dichloro-3-formyl benzoates using Vilsmeier reagent in a two pronged strategy - conventional heating and microwave irradiation method is reported. The reaction time has been brought down from hours to seconds in microwave irradiation method.     

A facile synthetic approach to novel spiro-oxindoles/acenaphthylen-1-ones containing benzo[1,4]thiazin-3-one ring via 1,3-dipolar cycloaddition

A series of spiro-oxindole derivatives containing spirobenzo[1,4]thiazin-3-one ring were synthesized regioselectively via a multicomponent 1,3-dipolar cycloaddition of isatin, 2-(4-methyl-benzylidene)-4H-benzo[1,4]thiazin-3-one and sarcosine or l-proline in toluene under reflux condition. Also spiro-acenaphthylen-1-ones containing spirobenzo[1,4]thiazin-3-one ring have been synthesized using 2-(4-methyl-benzylidene)-4H-benzo[1,4]thiazin-3-one as dipolarophile. The methodology affords high yields of products in short reaction time.