title: Template-assisted assembly: scanning tunneling microscopy study of solvent-dependent adlattices of alkyl-derivatized tetrathiafulvalene.
abstract: The self-assembly of an adsorbate as a function of the strength of solvent-substrate adsorption is an important yet relatively unexplored subject. In this study, how the strength of solvent-substrate adsorption and solvent-solvent attraction affects the assembly of tetrakis(octadecylthio)tetrathiafulvalene (1) is scrutinized by scanning tunneling microscopy (STM). For solvents with strong intermolecular interactions and adsorption onto graphite, such as long n-alkanes (C(n)H(2n+2), n ≥ 13), STM reveals that the solvent molecules form lamellae which become a template to direct the assembly of 1 into one-dimensional arrays. The lengths of one of the unit cell vectors for the assemblies are increased and well correlated with the solvent sizes. In situ STM monitoring of 1 introduced onto graphite with preadsorbed n-tetradecane adlattices shows that the developed assemblies of 1 have striped features aligned parallel to the underlying template. In contrast, for solvents with weak adsorption, such as short n-alkanes (C(n)H(2n+2), n ≤ 12), toluene, and 1,2,4-trichlorobenzene, the adlattice structures of 1 are solvent-independent.
authors.affiliation: Department of Chemistry, Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617.
authors.forename: Shern-Long
authors.initials: SL
authors.lastname: Lee
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Chu
authors.forename: Hung-Jen
authors.initials: HJ
authors.lastname: Wu
authors.forename: Chun-Hsien
authors.initials: CH
authors.lastname: Chen