Neutral gadolinium(III) complexes of bulky octadentate dtpa derivatives as potential contrast agents for magnetic resonance imaging

Abstract

A series of bulky and neutral gadolinium complexes of [bis(R-amide)dtpaH₃] (where R = Prⁱ,, Buⁱ,, Bz and phenylethyl, L¹--L⁴)) with potential application as contrast agents for magnetic resonance imaging has been prepared and characterized ; the relaxivity of these complexes is comparable to the contrast agent [Gd(dtpa)(H₂OO)]; which is which is currently used in clinics; the X-ray structure analysis of the gadolinium(III) complex of L³ reveals a neutral nine-coordinate complex featuring a water molecule in the tricapped trigonal prismatic metal coordination sphere.