Role of Fluorine Interactions in the Self-Assembly of a Functionalized Anthradithiophene Monolayer on Au(111)

Abstract

Scanning tunneling microscopy studies of the first monolayer of 2,8difluoro-5,11-(bis)triethylsilylethynyl anthradithiophene on Au(111) reveal two ordered structures with anthradithiophene planes parallel to the substrate. Submolecular resolution STM images demonstrate structures with a close approach of fluorine−sulfur and fluorine−fluorine atoms in the ordered structures. This provides evidence for the importance of noncovalent F−S and F−F in driving 2D self-assembly in the monolayer. Spectroscopic studies indicate a transport gap of 2.4 eV that is insensitive to the local domain structures, as expected for weak intermolecular interactions.

Rational Design of Organic Semiconductors for Texture Control and Self‐Patterning on Halogenated Surfaces

“…However, there is little insight into the roles of molecular design and interfacial interactions on molecular self‐assembly in the context of heterogeneous nucleation at the solution‐solid interface . A recent development in this area is the successful use of fluorine–fluorine (F–F) interactions between the conjugated molecule and the surface to control crystallization and engineer film ordering . Fluorine‐terminated OSCs can exhibit a differential microstructure when deposited on surfaces selectively treated with fluorinated self‐assembled monolayers (F‐SAM): the formation of crystalline domains consisting of (001)‐textured lamellar sheets of molecules, with in‐plane π‐stacking capable of effectively transporting charges at the semiconductor‐dielectric interface, only occurs on and in the vicinity of regions where the F–F interactions are present.…”

Coverage dependent molecular assembly of anthraquinone on Au(111)

“…We expect that this model is generic enough to apply with small modification to other related networks and may also provide guidance in explaining underlying mechanisms in other physical systems involving log-normal distributions. Given the increasing prevalence of disorder at molecular interfaces, 4,9 it is important to strengthen our quantitative statistical understanding of complex structures such as we describe here.…”

“…Imaging was conducted in constant-current mode using tungsten tips, and image calibration was accomplished using the known dimensions of the herringbone reconstruction. 9 The substrates were prepared in UHV, with a base pressure of ∼3 × 10 11 Torr, housing a commercial variable-temperature STM, Omicron VT-XA, connected by a gate valve to a separate organic deposition chamber. AQ was loaded as received (Sigma-Aldrich) into a glass ampoule sealed to a high-vacuum flange differentially pumped (to ∼5 × 10 7 Torr) behind a gate valve separating it from the deposition chamber.…”

“…[4][5][6][7] Importantly, molecular assemblies on surfaces are not necessarily well-ordered. For example, recent studies of manganese phthalocyanine on Bi 2 Te 3 show poor ordering, 8 cytosine on Au(111) shows a random pore network, 4 and second layers of diF-TES-ADT are disordered 9 despite ordering in the first layer. It is important to develop as much quantitative understanding of such disordered aggregates as possible.…”

Substituted pyrrolo[2,3-d]pyrimidines as Cryptosporidium hominis thymidylate synthase inhibitors

“…The sulfur atom of M519 is positioned to interact with N1 as well as 2’-Cl on the phenyl ring of compound 6 . The fluorine of FdUMP makes an additional electrostatic contact with hydroxyl of Y342 as well as a non-covalent interaction with sulfur atom of compound 6 10 .…”