Molecular Photo-Switch Development

We are developing new types of molecular photo switches, in which photo-isomerisation is triggered with bio-compatible wavelengths of red/near IR light for a range of applications in biological contexts. In particular, we are interested in photo-responsive receptors in which binding and guest sensing is regulated with light, for controlled uptake, release and imaging applications, as well as triggering catalytic processes. These include hydrogen bonding, halogen bonding and lanthanide-based systems. 

Recent works within the group have reported the synthesis and anion transport capabilities of azo-benzene based photo-switches. By appending anion receptors on either side of the N=N bond, we have demonstrated significantly weaker ion transport responses for the E isomer than for the Z isomer, due to the cooperativity of the anion coordination event (see figure to the right, Chem. Sci., 2020). This approach has been studied for both hydrogen and halogen bonding systems (Chem. Comm., 2023) and has included an in-depth study on the effects of ortho-halogen and chalcogen substitution on the photochemistry of the azo-benzene (Chem. Sci., 2022). 

Additionally, the group has demonstrated the efficacy of tetraphenylethylene based photo-switches which show anion dependent aggregation induced emission (AIE) and photo-regulated anion binding (see figure below, Angew. Chem. Int. Ed., 2021).