Carole Arnal-Herault

Supramolecular self-organization in constitutional hybrid materials

We present in this paper a new strategy to transcribe the supramolecular dynamic self-organization of the G-quadruplex and ureidocrown ether ion channel-type columnar architectures in constitutional hybrids. In particular, the use of a “dynamic reversible hydrophobic interface” can render the emerging hybrid mesophases self-adaptive. The reversible hydrophobic interactions allow both supramolecular and inorganic silica components to mutually (synergistically) adapt their spatial constitution during simultaneous (collective) formation of micrometric self-organized hybrid domains. More generally, applying such consideration to materials, leads to the definition of constitutional hybrid materials, in which organic (supramolecular)/inorganic domains are reversibly connected. This might provide new insights into the features that control the design of functional materials.

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.