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Updated: Sep 9, 2026

Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
A lanthanum complex with 3,4,5,6-tetra-bromophthalate as ligand
Christine Hénaff1, Thierry Roisnel2, Chloé Blais1
1Univ Rennes, INSA Rennes, CNRS UMR 6226 "Institut des Sciences Chimiques de Rennes", 35708 Rennes, France.
Abstract:
A lanthanum-based complex, heptaaqua(3,4,5,6-tetrabromobenzene-1,2-dicarboxylato)(3,4,5,6-tetrabromo-2-carboxybenzoato)lanthanum(III), [La(C8Br4O4)(C8HBr4O4)(H2O)7] or [La(tbpa)(Htbpa)(H2O)7], where H2tbpa is 3,4,5,6-tetra-bromo-phthalic acid, was prepared by microwave-assisted reaction between lanthanum chloride and 3,4,5,6-tetra-bromo-benzene-1,2-di-carb-oxy-lic or tetra-bromo-phthalic acid in water. The La3+ is nine-coordinated by seven oxygen atoms from coordinated water mol-ecules and two oxygen atoms from two different ligands in a slightly distorted D 3h spherical tricapped trigonal prismatic geometry. The crystal packing features a hydrogen-bonding network and Br⋯Br inter-actions.
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