Study of Copper Complexes Absorbed on a Silica Gel Surface Chemically Modified with 5-Amino-1,3,4-thiadiazole-2-thiol

Catalytic Activity of Molybdenum(II) Complexes in Homogeneous and Heterogeneous Conditions

“…The reaction between complex [Mo­(η 3 -C 3 H 5 )­Br­(CO) 2 (NCCH 3 ) 2 ] ( 1 ) and silica functionalized with the same 3-(2-amino-1,3,4-thiadiazole)­propyl ligand ( Silica-L , Scheme ) afforded a new material ( Silica-C1 ). Elemental analysis shows approximately 7.63 wt % Mo (0.76 mmol g –1 ) of molybdenum in Silica-C1 , while the values for C, H, N, and S suggest that one nitrile remains coordinated to the metal.…”

“…The cage polymer octakis­(3-chloropropyl)­octasilsesquioxane ( Cube ) was prepared by stirring 3-chloropropyltriethoxysilane in methanol for 6 weeks under acidic conditions. Reaction with the ligand L , in a molar ratio of 1:12, under reflux in anhydrous dimethylformamide, for 12 h, led to octakis­[3-(2-amino-1,3,4-thiadiazole)­propyl]­octasilsesquioxane ( Cube-L ). , Silica gel functionalized with 3-chloropropyl was obtained by reaction of silica gel, previously activated (heated for 4 h at 150 °C under 10 –3 Torr), with 3-chloropropyltriethoxysilane in dry xylene. After drying the resulting white powder, Silica-Cl , under vacuum and degassing (10 –3 Torr) for 6 h at room temperature, it was reacted with 2-amino-1,3,4-thiadiazole in dimethylformamide for 40 h at 110 °C …”

“…The ligand chosen was 2-amino-1,3,4-thiadiazole, which offers several possibilities for coordination through the ring atoms and bears a NH 2 group, which is important for immobilization purposes. − Complexes of Co­(II) and Ni­(II) with the related 2-aminothiazole were reported to inhibit cancer cell growth, mainly owing to their complex–DNA binding ability, suggesting other applications for the new complexes…”

Some New Data for Metal Desorption on Inorganic–Organic Hybrid Materials

“…In this sense, various simple or complex molecules have been anchored on the surface of these materials in order to explore some of their practical applications (2,(4)(5)(6)(7)(8). Particular attention has been paid to the alcoxysilanes with nitrogen as the Lewis base, owing to their applicability in several studies, such as immobilization of biologically interesting molecules (9), support for catalysts (10), photoluminescence studies (11), immobilization of humic acid (12), chromatographic separations of some metabolites (13), and preconcentration of metals from dilute solution (14). The last application mentioned has already been well explored in order to find new metal extractant materials for use in environmental chemistry (15).…”

Solid-Phase Extraction for the Decontamination of Alkali Metal, Alkaline Earth Metal, and Ammonium Salts from Heavy Metal Ions

“…Silica gel used as a bonded stationary phase for the chelating ligands has attracted the analytical chemists as it does not swell or strain, has good mechanical strength, undergoes heat treatment together with ease of immobilization of the chelating ligands (8). Quite a good deal of the literature appears to deal with chelating polymers on the silica support for selective separation of metal ions (9)(10)(11)(12)(13). Additional improvement in the process was achieved using surfactant as coating material on C 18 bonded silica, the formation of new stationary phase with silica gel bonded cationic polyelectrolyte with ferron as counterion and ion-pair formation between a metal complex and a long chain quarternary ion pair on silica gel (14-21).…”