| | | | | | | webmail : intra-extra| Accès VPN| Accès IST| Contact | Français
Scanning Tunneling Microscopic Study of Molecular Self-Assembly on a Surface
 
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
Thu, Jan. 08th 2015, 10:30
NIMBE Bat.127, p.26, CEA-Saclay

Integration of functional organic molecules on a surface is one of the most important challenges to develop the molecule-based devices with controlled nanoarchitect designs. Fabrication of controlled two-dimensional organizations via self-assembly would be achieved by the understanding of several intermolecular interactions such as molecule-molecule, molecule-substrate, and molecule-solvent interactions. In this contribution, we present our recent studies on the formation and transformation of two-dimensional structures in thermally-responsive isobutenyl compounds possessing long alkyl tails to achieve various nano-patterns. Effects of alkyl chain length, linkage, and thermal treatment on the two-dimensional structures were studied by using the scanning tunneling microscopy (STM) at the highly oriented pyrolytic graphite (HOPG)/liquid interface.

Modulations of two-dimensional structures in the isobutenyl ester compounds with C18-21 alkyl chains were found due to odd-even effect, whereas those with shorter alkyl tails (C14-17) displayed the unified structures. This is also the case for amide-linked isobutenyl compounds, namely the compounds with C18-21 alkyl chains displayed either wavy or tripod structures due to odd-even effect of alkyl chain units, whereas those with C14-17 formed the same zig-zag structure. These results suggest that there is a specific alkyl chain length range that shows odd-even alkyl chain length effect in the isobutenyl compounds. The ether function of the isobutenyl compounds could be transformed into hydroxyl group by a thermal reaction of tandem Claisen rearrangement (TCR). After the TCR, all the 2D structures were converged into the same linear structures, and odd-even effect was completely quenched for both compounds.

 

References: Y. Kikkawa, Trans. Mat. Res. Soc. Japan, 39, 99-104 (2014); Polym. J., 45, 255-260 (2013); Y. Kikkawa, T. S. Balaban et al. Chemistry Eur. J. 19, 11293-11300 (2013); Y. Kikkawa, K. Hiratani et al. Chem. Commun. 50, 13146-13149 (2014); Org. Biomol. Chem., 10, 8087-8094 (2012); Chem. Lett., 41, 1196-1198 (2012); Chem. Commun., 46, 8008-8010 (2010); Chem. Lett., 39, 1039-1041 (2010); Colloid Surf. A, 356, 58-62 (2010).

 

Retour en haut