Journal of Colloid and Interface Science, Vol.261, No.2, 441-450, 2003
2,3-di-n-decyloxy-6,7-dichloroanthracene (Cl(2)DDOA), a new low-molecular-mass fluorescent organogelator: physical properties and structures
To extend the family of 2,3-didecyloxyanthracene (DDOA, 1), an organogelator having a rodlike shape, a high polarity, and fluorescing properties, the 6,7-dichloro derivative (Cl(2)DDOA, 2), was designed and prepared. Compound 2 forms gels in alcohols, nitriles, and alkanes. The electronic absorption spectra of the gel show a finer structure than those of the isotropic solutions, pointing to a specific degree of packing of the molecules; such an aggregation mode is also supported by fluorescence data. The gel-to-sol temperatures (T-m) were determined as a function of gelator concentration and the corresponding enthalpies (DeltaH(m)) were extracted. Scattering experiments have shown that the molecular packing in aggregates of 2 organogels is less reminiscent of the crystalline state than was the situation with DDOA gels. 2 organogels in butanol are made up of 120 Angstrom radius fibers much thinner than those observed in DDOA gels (r ca. 300 Angstrom) and with rather monodisperse cross sections. In 1-octanol, dodecane, or cyclohexane, the fibrillar organogel networks involve a broader distribution of the related cross sections through anisometric sections of the fibers and/or formation of bundles. (C) 2003 Elsevier Science (USA). All rights reserved.
Keywords:organic gels;polycyclic aromatic hydrocarbons;small angle neutron and X-ray scattering;fibrillar network