Mathieu Michau

Imidazole‐Quartet Water and Proton Dipolar Channels

Powerful synthetic scaffolds mimicking natural proteinfunctions unlock the door to a world of interactive materialsparalleling that of biology. Numerous artificial systemsshowing a rich array of interconverting ion-channel conduc-tance states in phospholipid and polymeric membranes havebeen developed in the last decades.

Self-organized proton conductive layers in hybrid proton exchange membranes, exhibiting high ionic conductivity

We describe a proton exchange membrane (PEM) system in which the self-organization of molecular precursors generates directional proton layers of high ionic group content in a scaffolding hydrophobic hybrid material. In particular, the use of the self-assembling strategy of molecular precursors is noteworthy and we have shown in this paper that it led to self-organized directional proton layers along hundreds of nanometers. The PEM hybrid membranes are homogeneous, flexible and show both thermal and chemical stability. They were surveyed for their ability to form proton layers reaching high ionic conductivities. The simple synthesis procedure and good conductivity/methanol permeability selectivity suggest that the hybrid membranes may be promising candidates for use in DMFCs.

Cation–π interaction: a case for macrocycle–cation π-interaction by its ureidoarene counteranion

We report the solid state structures of homocomplex [1·K]+[I]− and of heterocomplexes [1·K]+[3·I]− and [1·K]+[4·I]. In the [1·K]+[I]− complex the apical position of the K+ in the macrocycle is occupied by a –CH2– moiety of a neighboring 18-crown-6, consistent with a close contact and corresponding to ‘agostic’ interactions between K+ and –CH2– moieties. In the [1·K]+[3·I]− complex the second apical site of the cation is coordinated by a bridging water molecule which is simultaneously H-bonded to both the phenol hydroxyl and the iodide anion. In the [1·K]+[4·I]− complex the second apical site of the cation is occupied by the indole moiety. Moreover, the new heterocomplex system [1·K]+[4·I]− presented here, despite the multiple possibilities of K+–π contacts with the sterically available phenyl, phenyl-indole and pyrrole-indole rings of 4, shows that the pyrrolo C2C3 double bond is a versatile π-donor. 1H NMR results led us to conclude that the complexes adopt similar conformations in solution to those observed in the solid state.

Homomeric and heteromeric self-assembly of hybrid ureido–imidazole compounds

The H-bond mediated self-assembly of hybrid ureido–imidazole compounds has shown that the relative spatial position of the H-bonding groups directs homomeric or heteromeric association of the molecules in the solid state.