Striking Correlation between the Unusual Trigonal Crystal Packing and the Ability to Self-Assemble into Nanofibers of 2,3-Di-n-alkyloxyanthracenes

The space group of the crystals of derivatives of 2,3-dialkoxyanthracenes is monoclinic P2(1)/a (herringbone structure) with the linear ethyl or propyl chains but abruptly changes to the trigonal P (3) over bar or R (3) over bar space group for butyl to heptyl chains. Strikingly, this switch is correlated with the capacity of these compounds to self-assemble into nanofibers and organogels. Besides. compounds with a chain length exceeding seven carbon atoms could not be crystallized in accordance with the analysis of the projected crystal structure but are nevertheless excellent organogelators, The study of this series of compounds suggests a tight link between the molecular structure of the crystals and that of the organogels.