Anthony Kermagoret  

Université Aix Marseille, CINAM

Energy ratchet based on cucurbituril pseudo-rotaxanes

The quest toward synthetic molecular motors relies on energy ratchet mechanisms, via controlling the depth of energy wells and the height of kinetic barriers.^[1]

Actually macrocycles and host:guest complexes present a high potential to imagine artificial molecular machines working out-of-equilibrium in water.

Cucurbit[n]urils (CB[n]), used in a plethora of applications in water including molecular machines, have recently been reported in systems working away from equilibrium.^[2]

In this context we exploited the negative electrostatic potential of the carbonyl rims of CB[n] to build pH responsive pseudo-rotaxanes using a diacid-viologen guest. In competition with a the RedOx responsive cystamine guest, we were able to make an energy ratchet host:guest systems.^[3]

Moreover acid-viologen are interesting ligands to prepare photochromic materials.^[4]

[1] MN Chatterjee, ER Kay and DA Leigh, J. Am. Chem. Soc. 2006, 128, 4058.

[2] I Hwang, RD Mukhopadhyay, P Dhasaiyan, S Choi, S-Y Kim, YH Ko, K Baek and K Kim, Nat. Chem. 2020, 12, 808.

[3] X Yang, Q Cheng, V Monnier, L Charles, H Karoui, O Ouari, D Gigmes, R Wang, A Kermagoret and D Bardelang, Angew. Chem. Int. Ed. 2021, 60, 6617.

[4] X Yang, M Giorgi, H Karoui, D Gigmes, V Hornebecq, O Ouari, A Kermagoret and D Bardelang, Chem. Commun. 2019, 55, 13824.