Vasovist is the tradename of a Gd(III) complex which was the first intravascular contrast agent (see

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Vasovist® is the tradename of a Gd(III) complex which was the first intravascular contrast agent (see Box 4.3) approved in the EU for use in magnetic resonance angiography. Interactions between the lipophilic domain of the contrast agent and human serum albumin allow Vasovist® to bind reversibly to the protein. Vasovist® has the formula Na3[GdL(OH2)] where the ligand Ln− is derived from HnL shown in Fig. 27.12. 

(a) What is the value of n in Ln− and HnL? 

(b) Explain why one part of the ligand is described as being lipophilic.

(c) In Na3[GdL(OH2)], the Gd3+ ion is 9-coordinate. Suggest a possible coordination environment for the metal ion, and indicate how Ln− is likely to coordinate to Gd3+

(d) Why is HnL chiral? 

(e) Starting from (R)-HnL, four diastereoisomers of [GdL(OH2)]3− are possible: ΔR, R, ΔR,S, ∧R,R, ∧R,S. How do these arise? 

(f) The FAB mass spectrum of Na3[GdL(OH2)] shows peak envelopes at m/z 981, 959, 937 and 915. Suggest assignments for these peaks.


Box 4.3.

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Figure 27.12.

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Inorganic Chemistry

ISBN: 9781292134147

5th Edition

Authors: Catherine Housecroft

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