STUDY OF COPPER-COMPLEXES ADSORBED ON A SILICA-GEL SURFACE CHEMICALLY-MODIFIED WITH 2-AMINO-1,3,4-THIADIAZOLE

Citation
Nl. Dias et al., STUDY OF COPPER-COMPLEXES ADSORBED ON A SILICA-GEL SURFACE CHEMICALLY-MODIFIED WITH 2-AMINO-1,3,4-THIADIAZOLE, Colloids and surfaces. A, Physicochemical and engineering aspects, 141(2), 1998, pp. 181-187
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry Physical
ISSN journal
0927-7757
Volume
141
Issue
2
Year of publication
1998
Pages
181 - 187
Database
ISI
SICI code
0927-7757(1998)141:2<181:SOCAOA>2.0.ZU;2-2
Abstract
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 ace tone and ethanol solutions: at 298 K. The following equilibria constan ts (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(Cl O4)(2): 1.8 x 10(3) (ac), 1.0 x 10(3) (eth); ac = acetone, eth = ethan ol. The electron spin resonance spectra of the surface complexes indic ated a tetragonal distorted structure in the case of lower degrees of metal loading on the chemically modified surface. The d-d electronic t ransition spectra showed that for the ClO4-, complex, the peak of abso rption 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 Science B.V. All rights rese rved.