Département de chimie moléculaire

Amphiphilic iron chelators based on the 8-hydroxyquinoline moiety were synthesized in order to study their potential trend to aggregate into more complex structures. The QS10 and QS4 ligands only differ by the length of the lipophilic alkyl chain (C10 and C4, resp.) tethered to the chelating subunit. Physicochem. investigations in aq. soln. were performed to det. the global stability consts. of the iron complexes. At physiol. pH, the [Fe(QS10)3]3- predominant species undergoes time-dependent reorganization, as evidenced by cryogenic transmission electron microscopy: after a few hours of equilibration, iron-rich micelles arranged in large clustered structures were obsd., whereas after several days complexes were assembled into nanospheres with typical diams. of 100 to 200 nm. This pattern is different from the previous reported amphiphilic catechol deriv. and highlights the importance of the nature of the chelating subunit and the residual charge on the type of aggregates formed. These results are relevant to mimic the properties of siderophores from marine bacteria. [on SciFinder(R)]