Aquaporin

Organic chemistry

Water transport

Membrane

Structural engineering

Pillar

Engineering

Bilayer

Chemical physics

Chemistry

Materials science

Molecule

Lipid bilayer

Water flow

Chemical engineering

Permeation

Biochemistry

Environmental engineering

Angewandte Chemie International Edition

Artificial water channels mimicking natural aquaporins (AQPs) can be used for selective and fast transport of water. Here, we quantify the transport performances of peralkyl‐carboxylate‐pillar[5]arenes dimers in bilayer membranes. They can transport ≈10 7 water molecules/channel/second, within one order of magnitude of the transport rates of AQPs, rejecting Na + and K + cations. The dimers have a tubular structure, superposing pillar[5]arene pores of 5 Å diameter with twisted carboxy‐phenyl pores of 2.8 Å diameter. This biomimetic platform, with variable pore dimensions within the same structure, offers size restriction reminiscent of natural proteins. It allows water molecules to selectively transit and prevents bigger hydrated cations from passing through the 2.8 Å pore. Molecular simulations prove that dimeric or multimeric honeycomb aggregates are stable in the membrane and form water pathways through the bilayer. Over time, a significant shift of the upper vs. lower layer occurs initiating new unexpected water permeation events through toroidal pores.

Biomimetic Approach for Highly Selective Artificial Water Channels Based on Tubular Pillar[5]arene Dimers