title: Entropy-controlled 2D supramolecular structures of N,N'-bis(n-alkyl)naphthalenediimides on a HOPG surface.
abstract: The two-dimensional supramolecular structures of a series of N,N'-bis(n-alkyl)naphthalenediimides (NDIs), whose chain lengths span from C3 to C18, at a liquid-HOPG surface interface, studied by STM and FM-AFM, are assigned with the help of molecular dynamics/molecular mechanics calculations to demonstrate that the C3- and C4-NDIs show lamellar structures, the C4- to C12-NDIs show honeycomb (KAGOME) structures, and the C14- to C18-NDIs show lamellar structures again. The change in supramolecular structure depending on chain length can be explained semiquantitatively by the balance of entropy and enthalpy terms to show the importance of "self-avoiding walk" of the alkyl chain in entropy terms.
authors.affiliation: Research Center for Molecular-Scale Nanoscience, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Miyake
authors.forename: Toshi
authors.initials: T
authors.lastname: Nagata
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohta
authors.forename: Ryohei
authors.initials: R
authors.lastname: Kokawa
authors.forename: Takuji
authors.initials: T
authors.lastname: Ogawa