ARTICLE This journal isHighly ordered mesoporous silica SBA-15 with pendent 3-mercaptopropyl group has been prepared by condensation of surface silanols and (3-mercaptopropyl)trimethoxysilane. Treatment of the mercaptopropylated SBA-15 with (CH 3 CN) 2 PdCl 2 gave a heterogeneous Pd-catalyst. The immobilized Pd-catalyst served as an efficient heterogeneous catalyst for Sonogashira and Suzuki-Miyaura cross coupling reactions of aryl halides. Furthermore, the SBA-15 supported Pd-catalyst was recovered by a simple filtration from the reaction mixture and reused five times without significant loss of its catalytic activity.

Poly(hydroxamic acid)-poly(amidoxime) chelating ligands were synthesized from poly(methyl acrylate-co-acrylonitrile) grafted acacia cellulose for removing toxic metal ions from industrial wastewaters. These ligands showed higher adsorption capacity to copper (2.80 mmol•g -1 ) at pH 6. In addition, sorption capacities to other metal ions such as iron, zinc, chromium, and nickel were also found high at pH 6. The metal ions sorption rate (t 1/2 ) was very fast. The rate of adsorption of copper, iron, zinc, chromium, nickel, cobalt, cadmium and lead were 4, 5, 7, 5, 5, 8, 9 and 11 min, respectively. Therefore, these ligands have an advantage to the metal ions removal using the column technique. We have successfully investigated the known concentration of metal ions using various parameters, which is essential for designing a fixed bed column with ligands. The wastewater from electroplating plants used in this study, having chromium, zinc, nickel, copper and iron, etc. For chromium wastewater, ICP analysis showed that the Cr removal was 99.8% and other metal ions such as Cu, Ni, Fe, Zn, Cd, Pb, Co and Mn removal were 94.7%, 99.2%, 99.9%, 99.9%, 99.5%, 99.9%, 95.6% and 97.6%, respectively. In case of cyanide wastewater, the metal removal, especially Ni and Zn removal were 96.5 and 95.2% at higher initial concentration. For acid/alkali wastewater, metal ions removing for Cd, Cr and Fe were 99.2%, 99.5% and 99.9%, respectively. Overall, these ligands are useful for metal removal by column method from industrial wastewater especially plating wastewater.

Abstract-In this study Moringa oleifera leaves (biosorbent) is used for Cadmium (II) removal from water as a natural alternative for synthetic sorbents. Synthetic water was used to find optimum conditions for water treatment using biosorbent. The effect of biosorbent dosage and particle size, contact time, and pH effect were studied. Atomic Absorption Spectroscopy (AAS) was used to monitor the Cd (II) concentration before and after treatment with biosorbent. Fourier Transform Infrared Spectroscopy (FTIR) was used to monitor biosorbent structure changes before and after loading with Cd (II). Many parameters were studied such as: dosage of biosorbent (1 -10 g/L), contact time (2 -20 min), particle size (2 mm, 1 mm, 500 µm, 250 µm, and <250 µm), pH range (4-10), and Cd (II) concentrations (1, 3, 5, and 7 ppm). The statistical analysis of studied parameters showed that all parameters has an effect on Cd (II) removal with p values <0.05 except pH. FTIR result showed changes in the finger print area of biosorbent functional groups due to adsorption of Cd (II). As a conclusion, Moringa oleifera leaves can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Cd (II) from water.

SBA-16-supported Pd-complex (100–500 mol ppm) catalyzed the Heck, Suzuki and Sonongashira cross-coupling reactions under mild reaction conditions without a significant loss of its activity.

No abstract

The light induced behaviour of siloxane substituted azobenzene compounds in the presence of alkylene spacers is reported for the first time. Firstly, these photosensitive compounds were synthesized and elucidated the molecular structure by spectral analysis such as NMR, FTIR, and UV/Vis. Photoisomerization effect was evaluated in solution and also in nematic phase. The photosaturation occurred exactly at 29 seconds, whereas thermal back relaxation was observed ranging from 19.8 to 23.8 hours. Long duration of the thermal back relaxation is due to the presence of sterically hindered siloxane group substituted to the azobenzene molecules. Decrease in the duration of cis-trans isomerization was found when the number of alkylene spacers was increased. These siloxane based azobenzene derivatives are useful for the fabrication of optical storage device and molecular switches.

Pyridinyl functionalized MCM-48-supported Pd-catalyst efficiently (0.013–0.025 mol%) promoted Heck, Suzuki and Sonogashira cross-coupling reactions. Moreover, the catalyst was reused five times without significant loss of its activity.

Highly active khaya cellulose supported poly(hydroxamic acid) functionalized copper catalysts were synthesized and applied for the C–N bond formation reactions.