Study of copper complexes adsorbed on a silica gel surface chemically modified with 2-amino-1,3,4-thiadiazole
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Data
1998-11-01
Autores
Dias, N. L.
Gushikem, Y.
Franco, D. W.
Schultz, M. S.
Vasconcellos, LCG
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier B.V.
Resumo
The isotherms of adsorption of CuX2 (X=Cl-, Br-, ClO4-) by silica gel chemically modified with 2-amino-1,3,4-thiadiazole were studied in acetone and ethanol solutions: at 298 K. The following equilibria constants (in 1 mol(-1)) were determined: (a) CuCl2: 3.5 x 10(3) (ac), 2.0 x 10(3) (eth); (b) CuBr2: 2.8 x 10(3) (ac), 2.0 x 10(3) (eth); (c) Cu(ClO4)(2): 1.8 x 10(3) (ac), 1.0 x 10(3) (eth); ac = acetone, eth = ethanol. The electron spin resonance spectra of the surface complexes indicated a tetragonal distorted structure in the case of lower degrees of metal loading on the chemically modified surface. The d-d electronic transition spectra showed that for the ClO4-, complex, the peak of absorption did not change for any degree of metal loading, and for Cl- and Br- complexes, the peak maxima shifted to a higher energy region with a lower metal loading. (C) 1998 Elsevier B.V. B.V. All rights reserved.
Descrição
Palavras-chave
copper complex with 2-amino-1,3,4-thiadiazole, electron spin resonance of copper complexes, silica gel, silica gel modified with 2-amino-1,3,4-thiadiazole, 2-amino-1,3,4-thiadiazole
Como citar
Colloids and Surfaces A-physicochemical and Engineering Aspects. Amsterdam: Elsevier B.V., v. 141, n. 2, p. 181-187, 1998.