Mn4+-, Tb-3+,Tb-4+-, and Er3+-activated red phosphors in the MgAl2Si2O8 system

Mn4+ doped and Tb-3+,Tb-4+, Er3+ co-doped MgAl2Si2O8-based phosphors were prepared by conventional solid-state synthesis at 1,300 A degrees C. They were characterized by thermogravimetry, differential thermal analysis, X-ray powder diffraction, photoluminescence, and scanning electron microscopy. The luminescence mechanism of the phosphors, which showed broad red emission bands in the range of 600-715 nm and had different maximum intensities when activated by UV illumination, was discussed. Such a red emission can be attributed to the intrinsic E-2 -> (4)A(2) transitions of Mn4+

Palladium(II) complexes assembled on solid materials: as catalysts for the -NO2 (nitro) to -NH2 (amine) reactions

Herein, a new series of [PdCl2(L)(2)] complexes where ligands are monodentate amine ligands bearing sulfonamide groups were synthesized, characterized using various techniques such as NMR, FT-IR, UV-Vis, and sc-XRD and investigated for their catalytic performance for the reduction of nitroarenes (2-nitroaniline, 4-nitroaniline, and nitrobenzene) in the presence of NaBH4 in water under heterogeneous conditions. Because the results show that the synthesized complexes are very efficient catalysts, materials using the selected palladium(II) complex supported by multiwall carbon nanotubes, silicon dioxide, and iron(II,III) oxide (Fe3O4) were fabricated by a simple-impregnation methodology, characterized by FT-IR, BET, TEM, and XRD techniques and investigated for their catalytic performance for the same reaction. Thus, a series of supported catalysts was designed with the aim of both enhancing catalytic activity and reducing noble-metal contents. Our findings serve to develop simple catalytic systems and this system can be easily used for catalytic reduction reactions which are the cornerstone of the production of important chemicals

Synthesis and characterization of half-sandwich ruthenium complexes containing aromatic sulfonamides bearing pyridinyl rings: catalysts for transfer hydrogenation of acetophenone derivatives

1099-0682N-(Quinoline-8-yl-aryl)benzenesulfonamides 1-6 were successfully synthesized by the reaction of 8-aminoquinoline and various benzenesulfonyl chlorides. Then, half-sandwich ruthenium complexes 7-12 were prepared from the reactions of 1-6 with [RuCl2(p-cymene)]2. The synthesized compounds were characterized by NMR and FTIR spectroscopy and elemental analysis, and compounds 8 and 9 were further analyzed by X-ray diffraction. The complexes were screened for their efficiency as catalysts in the transfer hydrogenation of acetophenone derivatives to phenylethanols in the presence of KOH with 2-propanol (as hydrogen source) at 82 °C, and they all showed good activity. Complexes 10 and 12 were the most active (turnover frequency values: 703 and 734 h-1, respectively)