Dipole-Controlled Self-Assembly of 2,7-Bis(n-alkoxy)-9-fluorenone: Odd-Even and Chain-Length Effects

作者：Xu Li; Miao Xinrui^*; Zha Bao; Miao Kai; Deng Wenli

来源：Journal of Physical Chemistry C, 2013, 117(24): 12707-12714.

DOI：10.1021/jp403881t

• Analytical method
• Chemical homogeneity
• Even-odd effect
• Highly oriented pyrolytic graphite
• Lamellar patterns
• Self-assembled
• Self-assembled patterns
• Zig-zag structures

Fluorenone derivatives (F-OCn) with various lengths of peripheral alkyl chains (with carbon numbers of n = 12-18) were synthesized, and their self-assembled adlayers were investigated in solvents with different polarities and functionalities by scanning tunneling microscopy (STM) on a highly oriented pyrolytic graphite (HOPG) surface. The chain-length effect on the self-assembly of F OCeven was observed in 1-phenyloctane. With the shortening of the side chain, the self-assembled pattern changed from a dense- and loose-packed structure to a pliers-like structure. Self-assembly of F OCodd showed a uniform lamellar pattern. An even odd effect was observed resulting from the direction of the end methyl group in the alkyl chain unit. Furthermore, when the samples using dichloromethane as solvent were observed within 3 h, a less ordered lamellar structure appeared in most cases. The pliers-like pattern was observed for self-assembly of F-OC16 and F-OC14. However, F-OC(17)formed a zigzag structure. Observation of the odd even and chain-length effects on the self-assembled adlayers might provide an analytical method for examining the structural and chemical homogeneities.

• 出版日期2013-6-20
• 单位华南理工大学