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Gadolinium(III) Chloride

Author: Hans Lohninger

Gadolinium trichloride, GdCl3, is a colorless, hygroscopic, water-soluble solid. It is commonly encountered as hexahydrate GdCl36H2O. Gadolinium trichloride can be synthesized by the reaction of solid gadolinium with HCl at 600 C:

2 Gd + 6 HCl 2 GdCl3 + 3 H2

Another way to prepare gadolinium trichloride is to synthesize (NH4)2[GdCl5] which can be decomposed at 300C to GdCl3.

10 NH4Cl + 2 Gd 2 (NH4)2[GdCl5] + 6 NH3 + 3 H2
2 (NH4)2[GdCl5] {NH4[Gd2Cl7] + 3NH4Cl} 2 GdCl3 + 4 NH4Cl

Gd3+ ions are of special interest for magnetic resonance imaging (MRI), since the Gd3+ species has an f7 electronic configuration with seven unpaired electrons. This results in a highly paramagnetic behavior. As gadolinium salts are toxic, the Gd3+ ion has to complexed by a chelating agent (i.e. H5DTPA, diethylenetriaminepentaacetic acid) for usage in biomedical applications.

Last Update: 2011-02-16