Structural variations in a family of orthodialkoxyarenes organogelators

A series of low mass organic gelators (LMOGS) 1 to 6 whose chemical structures have in common an orthodialkoxyarene feature was prepared in order to compare the shape of their fibrillar network as investigated by small-angle neutron scattering (SANS) experiments. All members of the family exhibit a pronounced tendency to bundle formation by merging isolated fibers in extended packets of average diameter >500 Å. Variations of the 2D packing symmetry are observed from hexagonal to square orderings with close derivatives of the reference member 2,3-didecyloxyanthracene (DDOA). Networks in which the fraction of isolated fibers is significant enough to allow for their SANS identification are those for 6,7-dichloro-2,3-didecyloxyanthracene (Cl2DDOA) and 2,3-dodecyloxy-9,10-anthraquinone (5). For this latter, the monodispersity of the cross-sections (thickness = 74 Å) is remarkable and the rectangular shape (b/a∼0.12b/a∼0.12) accounts for a merging mechanism into anisotropic bundles (ribbons).

Neutron scattering studies characterize the solid-like gel network made up of ribbon-like aggregates with elliptical sections (b/a=0.12b/a=0.12, a=308 Åa=308 Å) and radially polydisperse cylindrical bundles (R=450 ÅR=450 Å) acting as nodal zones.Figure optionsDownload as PowerPoint slide