Thanks to a large variety of organic/macrocyclic synthetic tools, we are able to regioselectively functionalize the macrocyclic platforms with selected sets of coordinating "arms" (e.g. acetate, pyridyl, picolinate...) that allow us to finely tune the coordination properties of the chelators. Playing on the denticity and the hard/soft donor character of these ligands thus leads to a fine control of the chelate properties.

For instance, the use of bidentate picolinate units on the different platforms has lead to highly robust chelators for a wide range of cations, such as copper(II) (Inorg. Chem. 2012) or lanthanides(III) (Inorg. Chem. 2018; Inorg. Chem. 2020). Subtle modification of the chelator substitution pattern can also allow precise control of the inner coordination sphere of the lanthanide cations, with coordination or absence of a water molecule (Inorg. Chem. 2012), a feature that has a key impact in applications such as MRI (Magnetic Resonance Imaging) or luminescence.

The use of less common coordinating arms can also trigger peculiar properties to the chelates, as we have demonstrated for example with the use of thiazolyl groups that provide remarkable Cu(II)/Cu(I) redox stability (Dalton Trans. 2016), phosphine oxide pendants that allow specific coordination of Cu(II) ions versus their divalent congeners (Zn(II), Co(II), Ni(II)) (Inorg. Chem. 2023), or tridentate pyridylphosphonates that lead to the controlled formation of supramolecular constructs with lanthanide ions (Inorg. Chem. 2023; Inorg. Chem. 2020)