The unusual molecular organization of 2,3-bis(n-hexyloxy) anthracene in the crystal. A hint to the origin of the gelifying properties of 2,3-bis(n-alkyloxy)anthracenes?

Unlike most anthracene derivatives and other oblong shaped aromatics, 2,3-b is(n-hexyloxy) anthracene (DHOA) crystallizes in the space group R(-3) with unit cell parameters a = b = 14.639, c = 54.435 Angstrom. The molecular pa cking is composed of arrays of molecular triads. By computing the interacti on potential of all the molecules with one another in space group R(-3), th e lowest energy structure is found to be a triad and the lowest energy laye r a coplanar head-to-tail packing of these triads; most of the crystal ener gy is associated with the layer formation and the binding energy of the var ious structures is calculated to depend essentially on the non-bonded van d er Waals interactions. They might prefigure the arrangement of the anthrace ne nuclei in the gel network nodes formed by 2,3-di-n-alkoxyanthracenes who se alkyl chains possess six or more carbon atoms.