Self‐assembly of an unsymmetrical bolaamphiphile produces either lipid nanotubes with cationic inner surfaces or nanotapes, depending on the initial molecular packing, which in turn depends on the solvent conditions. The nanotubes have different inner and outer surfaces, covered with amino and sugar functionalities, respectively, and effectively encapsulate anionic nanomaterials in the hollow cylinder without depending on capillary action (see Figure).

A series of new calixarene-based fluoroionophores were synthesized. With our new calixarene derivative bearing a crown ether and an azacrown ether as two binding sites, the metal ion was found to selectively choose its better binding pocket between these two ligands. Interesting "molecular taekowndo" processes between Ag(+)-K(+), Cu(2+)-K(+), and Ag(+)-Cs(+) pairs were easily monitored via fluorescence change.

The new sugar-based gelators 1 and 2 were synthesized, and their gelation abilities were evaluated in organic solvents and in water. Compound 1 gelates both water and organic solvents whereas 2 gelates only organic solvents. Superstructural difference between hydrogel 1 and organogel 2 was investigated by CD, TEM, AFM, 1H NMR and XRD. Hydrogel 1 displays a well-developed helical ribbon structure with 20-150 nm diameter and a length of several hundred microm whereas organogel 2 shows a twisted fiber structure of diameter 20 nm. CD measurements of hydrogel 1 and organogel 2 indicate that hydrogel 1 maintains a well-ordered chiral structure whereas organogel 2 maintains a relatively disordered chiral structure. The 1H NMR and XRD results suggest that the hydrophobic interaction in hydrogel 1 are relatively weak, with a relatively small region interdigitated between lipophilic alkyl groups. In addition, upon irradiation at 254 nm wavelength, hydrogel 1 reveals a red coloration at 540 nm. These results indicate that the self-assembled hydrogel 1 was polymerized by UV-irradiation. The intensity of the CD spectrum of the polymerized hydrogel markedly decreased. This result indicates that upon polymerization the highly ordered chiral structure of hydrogel 1 changes to a disordered molecular packing structure.

Palladium-doped double-walled silica nanotubes (SNTs) were synthesized by sol-gel transcription, and H 2 adsorption experiments were carried out at 298 K. The H 2 -storage capacities of the palladium-doped SNTs were 0.15 wt % for SNT-5, 1.90 wt % for SNT-10, and 0.75 wt % for SNT-15, showing that the palladiumdoped tubes are very effective as an H 2 -storage material even at room temperature. Remarkably, SNT-10 had the highest storage capacity. The results indicate that palladium nanoparticles acted as the primary receptor for adsorption of atomic hydrogen. Also, this finding suggests that a moderate amount of palladium nanoparticles is important to effectively uptake H 2 in the nanotubes. We suggest that palladium-doped doublewalled SNTs are useful as H 2 -storage materials in fuel cells.

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Molecular self-assembly and network formation by gelators have stimulated related research studies intensively to answer the fundamental questions on the nature of this fascinating phenomenon. 1-8 Due to their potential applications to template materials synthesis, drug delivery, separations, and biomimetics, gels formed by molecular agents (gelators) were constituted an important class of functional materials. The aggregation of gelator molecules into fibrous networks is driven by multiple noncovalent interactions such as dipole-dipole, van der Waals, and H-bonding interacAmanokura, N.; Ono, Y.; Akao, T.; Shinmori, H.; Takeuchi, M.; Shinkai, S.; Reinhout, D. L. Kilic, S.; Xu, J.; Enick, R. M.; Beckman, E. J.; Carr, A. J.; Melendez, R. E.; Hamilton, A. D. Science 1999, 286, 1540. (d) Hafkamp, R. J. H.; Kokke, B. P. A.; Danke, I. M.; Geurts, H. P. M.; Rowan, A. E.; Feiters, M. C.; Nolte, R. Ono, Y.; Yoshihara, K.; Akao, T.; Shinmori, H.; Takeuchi, M.; Shinkai, S.; Reinhout, D. L. Hirata, T.; Inoue, D.; Kimura, M.; Touhara, H.; Shirai, H. Masuda, M.; Okada, Y.; Yase, K.; Shimizu, T. AdV. Mater. 2001, 13, 715. (b) Masuda, M.; Hanada, T.; Okada, Y.; Yase, K.; Shimizu, T. Macromolecules 2000, 33, 9233. (c) Nakazawa, I.; Masuda, M.; Okada, Y.; Hanada, T.; Yase, K.; Asai, M.; Shimizu, T.

A cholesterol derivative forms self-assembled helical ribbons in organic solvent, and treatment of this helical ribbon lipid as a template with Pd(Ac)2 provides helically-patterned arrays of palladium nanoparticles followed by reduction.