Stability and electronic spectra of copper(II) halides in butan-1-ol and the effects of R-OH type solvents on these properties.
Résumé
Copper(II) halide complexes were studied in butan-1-ol at 25°C and at constant ionic strength. Formation constants and electronic spectra of all the complexes present in the solution were calculated. The apparent stability of these complexes increases with the number of carbon atoms in the alcohol: the logarithm of the overall stability constant, βj is a linear function of their molecular weights. A regular decrease of the stability with the permittivity of the pure solvents is observed. This result is correlated with the increasing dissociating power of the solvents which promotes better hydrogen bonding and hinders the substitution of the solvent molecule by the ligand in the inner coordination sphere of the metal. There is hardly any ROH-type solvent effect on the electronic spectra of the individual species. Tetrabromocuprate is always present in D4h symmetry, whereas the configuration of tetrachlorocuprate is D4h in methanol and D2d in the higher alcohols.
Domaines
Chimie
Origine : Accord explicite pour ce dépôt