Research Overview

Anti-cancer drug design – molecular probes for biomolecules

Polyazaaromatic transition metal complexes arise from the assembly of heteroaromatic ligands around a metallic core. We have been working on Ru(II) and Ir(III), whose resulting complexes were shown to exhibit very interesting properties upon light irradiation, such as enhanced oxidative and reductive power or increased sensitivity towards their surrounding environment. These metal complexes have been further exploited in our laboratory to target specific biomolecules (such as DNA) in order to develop potential diagnostic[1] and therapeutic agents[2].

Figure 1: Molecular modelisation of the interaction of a RuII complex with telomeric DNA.[2]

[1] Q. Deraedt et al., Inorg. Chem. Front., 2017, 4, 91.

[2] G. Piraux et al., Chem. Eur. J., 2017, article ASAP.


Synthesis of light harvesting antenna – photoconversion of sunlight

Species resulting from the assembly of several metallic centers (polynuclear metal complexes) are known for their potential ability to harvest sunlight and transfer it to a specific site. We synthesize and study new supramolecular metallic entities able to transfer light energy from one site of the molecule to another one. We have elaborated different synthetic strategies to obtain multi-terpyridine ligands.[1] These macromolecular units are ideal building blocks for the construction of transition-metal-based supramolecular assemblies.

Figure 2: One-pot synthesis strategy of multi-tpy building blocks.[1]

[1] A. Jacques et al., J. Org. Chem., 2015, 80, 11143-11148.

Nano- and DNA-based materials for light induced hydrogen production

Molecular hydrogen is one of the best candidates to solve current issues of worldwide energy consumption. A photocatalytic hydrogen evolution reaction (HER) is thus a promising solution. Within a molecular approach, several components are usually required for an efficient HER: a catalyst, a photosensitizer (PS), a source of protons, and, in the case of half-reactions, a sacrificial electron donor. Cobalt(III) derivatives have drawn considerable attention as compounds that are efficient catalysts. We have developed several Ru(II)–Co (III) dyads covalently connected to each other and we have shown that they have higher photocatalytic activity than the independent units. In addition, Ir(III)–Co(III) dyads have also been prepared to benefit from the superiority of Ir(III) complexes in terms of photophysical and electrochemical tunability.[1,2]

Figure 3: Supramolecular system of Ir(III)-Co(III) dyad that photocatalytically produces hydrogen.[2]

[1] A. Jacques et al., Eur. J. Inorg. Chem., 2016, 1779-1783.

[2] C. Lentz et al., Inorg. Chem., 2017, article ASAP.


Photocatalytic reactions use visible light to trigger the transformation of a reactant into a given product. Polypyridinic transition metal complexes are excellent photoreducing and/or photooxidizing agents, which can be used as photoredox homogeneous catalysts in photocatalytic systems in which they show high activity but no recyclability. To solve this issue, we have covalently anchored on graphene oxide (GO) several photoredox active Ir(III) and Ru(II) complexes via esterification reaction and non-covalently fixed on reduced graphene oxide (rGO) via pyrene moieties.

dsDNA : a molecular electric wire

The transport of a positive and negative charge along double stranded deoxyribonucleic acid (dsDNA) is a great challenge. dsDNA-based nanomaterials are the subject of numerous researches. The extreme sensitivity of the charge migration process to lesions present in the double helical structure, such as mismatched base-pairs, can be probed using transition metal complexes. We have developed synthetic strategies to obtain modified nucleobases, either to construct a double helix where the natural H-bonded bases are replaced by metal-coordinated liganosides or to introduce a punctual modification inside a natural dsDNA structure.[1] In this view, we work on the synthesis and characterization of nucleosides bearing iridium complexes with unaltered properties compared to their parent complexes.

[1] J. Passays et al., Eur. J. Inorg. Chem., 2017, 623-629.