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Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
Steric control of lanthanide hydration state: fast water exchange at gadolinium in a mono-amide 'DOTA' complex
Aileen Congreve1, David Parker, Eliana Gianolio
1Department of Chemistry, University of Durham, South Road, Durham, DH1 3LE, UK.
Abstract:
Detailed analyses of the solution structure and exchange dynamics of two sets of homologous mono-amide triacetate lanthanide complexes (Ln = Eu, Gd) of cyclen have been undertaken. The complex [LnL1], bearing an N-linked CH2CH2NHCO-pyridyl moiety, forms mono-aqua (q = 1) species in solution and the Gd complex undergoes rapid water exchange (k(ex)= 11 x 10(7) s(-1), 298 K) as a result of the steric destabilisation of the Ln-water binding interaction. The homologous complex with a C-3 spacing chain, [LnL2], forms a q = 0 species.
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