Chlorides

Gadolinium III chloride, also known as gadolinium trichloride, is GdCl3. It is a colorless, hygroscopic, water-soluble solid. The hexahydrate GdCl3∙6H2O is commonly encountered and is sometimes also called gadolinium trichloride.

Gd3+ species are of special interest because the ion has the maximum number of unpaired spins possible, at least for known elements. With seven valence electrons and seven available f-orbitals, all seven electrons are unpaired and symmetrically arranged around the metal. The high magnetism and high symmetry combine to make Gd3+ a useful component in NMR spectroscopy and MRI.

Gadolinium III chloride is usually prepared by the "ammonium chloride" route, which involves the initial synthesis of (NH4)2[GdCl5]. This material can be prepared from the common starting materials at reaction temperatures of 230 °C from gadolinium oxide.

Gadolinium III Chloride Hexahydrate is an excellent water soluble crystalline Gadolinium source for uses compatible with chlorides. Chloride compounds can conduct electricity when fused or dissolved in water. Chloride materials can be decomposed by electrolysis to chlorine gas and the metal. They are formed through various chlorination processes whereby at least one chlorine anion (Cl-) is covalently bonded to the relevant metal or cation.

Gadolinium salts are of primary interest for relaxation agents in magnetic resonance imaging (MRI). This technique exploits the fact that Gd3+ has an electronic configuration of f7. Seven is the largest number of unpaired electron spins possible for an atom, so Gd3+ is a key component in the design of highly paramagnetic complexes. To generate the relaxation agents, Gd3+ sources such as Gadolinium chloride are converted to coordination complexes. Gadolinium Chloride can not be used as an MRI contrasting agent due to its low solubility in water at the body's near neutral pH