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Reinforced cross-bridged Ni2+-cyclam complexes were functionalised with pendant arms containing both amide protons and CF3 groups that lead to a dual 1H/19F response. The resulting complexes possess very high inertness favourable for MRI applications. The paramagnetism of the Ni2+ ion shifts the amide resonance 56 ppm away from bulk water favouring the chemical exchange saturation transfer (CEST) effect and shortening the acquisition times in 19F magnetic resonance imaging (MRI) experiments, thus enhancing the signal-to-noise ratios compared to the fluorinated diamagnetic reference.

The GdIII-complexes of DO3A-acetophenone and ortho- or para- hydroxyacetophenone ligands have been investigated to assess the effect of the presence of a phenol group on the relaxivity and on the water exchange rate of these potential MRI contrast agents. H-Bonding between the ortho-phenol(ate) groups and the water molecules involved in the dissociative exchange mechanism is shown to speed up the water exchange rate by stabilizing the eight-coordinate transition state.

Thanks to a smart regiospecific N-functionalization, a pyclen based ligand bearing one picolinate and two acetate arms organized in a dissymmetric manner was synthesized for Y

The complexation properties of H₂Me-do2pa towards (nat)Bi(3+) reveal a rather fast formation of the [Bi(Me-do2pa)](+) complex, which is endowed with a very high thermodynamic stability (log K(BiL) = 34.2) and presents a single non-fluxional structure in solution. X-ray diffraction and solution NMR studies showed an octadentate binding of the ligand to the metal ion. The labelling of H₂Me-do2pa with (213)Bi was performed and the resulting complex was stable in vitro, sustaining its use as an attractive alternative to taken here as a reference.

A Gd complex based on a polyphosphonated pyridyl ligand shows a very high stability in aqueous solution (logK EuL = 25.7), a high relaxivity (8.5 mM -1 s -1 at 25 °C and 20 MHz) and a marked and selective relaxivity enhancement (37%) in the presence of Mg 2+, opening interesting perspectives for the design of cation responsive contrast agents. © 2012 The Royal Society of Chemistry.

Corner-connected molecular squares were self-assembled from a three-component system formed by a bidentate ligand and two palladium or platinum complexes. The system is dynamic and the constitution of the species in solution can be modulated under stoichiometric control.