1222257-58-0Relevant articles and documents
Self-association of bis-dendritic organogelators: The effect of dendritic architecture on multivalent cooperative interactions
Seo, Myungeun,Kim, Jung Hak,Kim, Jisung,Park, Nojin,Park, Jeyoung,Kim, Sang Youl
experimental part, p. 2427 - 2441 (2010/06/20)
A series of bis-dendritic gelators consisting of a benzamide dendron and an alkyl dendron were synthesized to investigate the dendritic effect on self-assembly. The gelators with a firstgeneration benzamide (benzamide-G1) dendron or a first-generation alkyl (alkyl-G1) dendron formed stable gels in most aromatic solvents, and their self-assembled fibrillar networks were imaged by electron microscopy. The unbranched molecule (G0-G0) or the molecule possessing a second-generation benzamide (benzamide-G2) dendron did not form gels. Differential scanning calorimetry, powder X-ray diffraction, and Fourier transform IR studies revealed that introduction of a dendritic branch strongly affected the molecular packing as well as the strength of intermolecular interactions. Furthermore, concentration-dependent diffusion coefficient measurements and the evaluation of association constants by 1H NMR spectroscopy indicated that bis-dendritic gelators with a benzamide-G1 dendron possessed high association constants and formed large aggregates, whereas molecules with a single benzamide formed dimers in chloroform. The formation of self-assembled fibrillar networks was driven by the multivalent and cooperative hydrogen bonding observed in the benzamide- G1 dendrons. π- π stacking of aromatic groups and van der Waals interactions between alkyl chains also played roles in the self-assembly process, thus indicating that a spatial balance between two dendrons is important.
