Artículos de revistas
Silica-gel-immobilized Acetylacetone-some Thermodynamic Data In Non-aqueous Solvents
Registro en:
Thermochimica Acta. , v. 259, n. 1, p. 95 - 102, 1995.
406031
10.1016/0040-6031(95)02295-D
2-s2.0-0002043112
Autor
Airoldi C.
Alcantara E.F.C.
Institución
Resumen
Acetylacetone was covalently immobilized on silica gel to produce a new surface (Sil-ac), having 0.62 mmol of ligand attached per gram of silica, which was characterized by means of elemental analysis and physical measurements, before being submitted to calorimetric measurements. Thus, a suspension of this anchored surface in ethanol or acetone was calorimetrically titrated with divalent cations (Co, Ni, Cu, Zn, Cd, Hg). The resulting isotherms conformed to a modified Langmuir equation. After linearization of these isotherms, the enthalpies of cation/surface adsorption and the interfacial equilibrium constant, as well as the variation of free energies and entropies, were calculated. In acetone, adsorption of copper gives rise to an exothermic ΔH of - 93.38 ± 0.94 kJ mol-1, while cobalt, 41.80 ± 0.42 kJ mol-1, and zinc, 2.38 ± 0.02 kJ mol-1, give an endothermic adsorption. In ethanol, the endothermic ΔH of 52.64 ± 0.53 kJ mol-1 for zinc contrasts with the exothermic enthalpies of adsorption observed for other cations, especially for mercury, - 102.20 ± 1.02 kJ mol-1 and nickel, -137.70 ± 1.38 kJ mol-1. © 1995. 259 1 95 102 Iler, (1979) The Chemistry of Silica, , Wiley, New York D'Hamers, Philippaerts, der Voort, Vansant, Siloxane bridges as reactive sites on silica gel. Fourier transform infrared?photoacoustic spectroscopic analysis of the chemisorption of diborane (1990) Journal of the Chemical Society, Faraday Transactions, 86, p. 3747 Deschler, Kleinschmit, Panster, 3-Chloropropyltrialkoxysilanes?Key Intermediates for the Commercial Production of Organofunctionalized Silanes and Polysiloxanes (1986) Angewandte Chemie International Edition in English, 25, p. 236 Bogart, Leyden, Wade, Schafer, Carr, (1989) J. Chromatogr., 483, p. 209 Kurusu, Synthesis and Reaction of a Silica-Supported Catalyst with Ammonium Groups. Immobilized Ammonium Groups on Silica (1990) Journal of Macromolecular Science: Part A - Chemistry, 27, p. 1389 Simonzadeh, Schilt, Chelation Properties of Silica-Bound 1,10-Phenanthroline (1989) Journal of Coordination Chemistry, 20, p. 117 Airoldi, Alcântara, Chemisorption of some metal(II) chlorides on silica-immobilized acetylhydrazine (1989) Colloids and Surfaces, 39, p. 219 Kudryavtsev, Bernadyuk, Lisichkin, Ion exchangers based on modified mineral carriers (1989) Russian Chemical Reviews, 58, p. 406 Kallury, Lee, Thompson, (1993) Anal. Chem., 65, p. 2459 Haan, van den Bogarert, Bongeé, van der Ven, Characterization of modified silica powders by fourier transform infrared spectroscopy and cross-polarization magic angle spinning NMR (1986) Journal of Colloid and Interface Science, 110, p. 591 Lisichkin, Kudryavtsev, Nesterenko, (1993) J. Anal. Chem. USSR, 38, p. 1288 Airoldi, Alcântara, Nakamura, Paixão, Vargas, (1993) J. Mater. Chem., 3, p. 479 Gona̧lves, Airoldi, (1989) Polyhedron, 8, p. 2901 Pyell, Stork, (1992) Fresenius J. Anal. Chem., 343, p. 576 Airoldi, Gushikem, Espínola, Adsorption of divalent cations on the silica-gel surface modified with N-(2-aminoethyl-3-aminopropyl) groups (1986) Colloids and Surfaces, 17, p. 314 Spokenko, Trofimchuk, Zaitsev, (1982) Russ. J. Inorg. Chem., 27, p. 1458 Gushikem, Silva, (1985) J. Colloid Interface Sci, 107, p. 81 Gona̧lves, Airoldi, Immobilized 3-aminopyridine on silica: Adsorption of some metal (II) chlorides in non-aqueous solutions (1987) Colloids and Surfaces, 28, p. 199 Airoldi, Santos, (1994) J. Mater. Chem., 4, p. 1479 Tavares, O'Sullivan, Hauser, (1962) J. Org. Chem., 27, p. 1251 Joshi, Pathak, (1977) Coord. Chem. Rev., 22, p. 37 Breitmaier, Voelter, 13C NMR Spectroscopy: Methods and Applications in Organic Chemistry (1987) 13C NMR Spectroscopy: Methods and Applications in Organic Chemistry, , 2nd edn., New York Tanamushi, (1983) Adsorption from Solution, , Academic Press, New York Jednacak-Biscan, Pravdic, (1980) J. Colloid Interface Sci., 75, p. 322 Jednacak-Biscan, Pravdic, Adsorption phenomena on glass surfaces. III. a microcalorimetric study of adsorption of n-butanol on heat treated surfaces of controlled pore glass (1982) Thermochimica Acta, 53, p. 203 Airoldi, Santos, Jr., (1986) Thermochim. Acta, 104, p. 111 Airoldi, Chagas, (1992) Coord. Chem. Rev., 119, p. 29