Highly ordered self-assembled architectures of modified terpyridines on highly ordered pyrolitic graphite imaged by scanning tunneling microscopy

Scanning tunneling microscopy has been used to study the adsorbed phases of functionalized terpyridines at the solid-liquid interface of highly ordered pyrolitic graphite (HOPG). Terpyridines are well-known for their complexing behavior to transition metal ions, making them widely used ligands in organometallic and supramolecular chemistry. We found that solutions of 2,2:6,2-terpyridine-4-oxydodecane (tpy-O-C12) and 2,2:6,2-4-oxyoctadecane (tpy-O-C18) form highly ordered two- dimensional (2D) arrays on HOPG in phenyloctane. For both compounds, large, well-defined lamellar domains have been observed with domain sizes larger than 500 nm. Sequential scans of an area with two grain boundaries indicate that desorption-resorption is taking place along the domain edges. High-resolution images of the lamella have been obtained, and the 2D packing within the lamella was determined in detail. The terpyridines align in long uniform double rows with their alkyl chains packing in an alternating, zipper-like fashion. The terpyridines pack with the polar head-groups head to head, and the observed size and shape of the molecules fit exactly to their modeled geometries

New 4'-functionalized 2,2':6',2''-terpyridines for applications in macromolecular chemistry and nanoscience

The well-known reaction of 4'-chloro-2,2':6',2''-terpyridine with alkoxide nucleophiles leads to 4'-functionalized 2,2':6',2''-terpyridines. This reaction allows the easy introduction of different functional groups onto the terpyridine at the 4'-position, i.e., opposite to the metal binding site, in one reaction step. Among the functionalized 2,2':6',2''-terpyridines reported here are amines (including chiral examples), carboxylic acids, simple alkoxy-chain terpyridines with different chain lengths, and a stilbene-functionalized terpyridine (I). Moreover, the synthesis of two important already known substances was significantly improved. One example of a sequential functionalization of an (aminopentoxy)terpyridine with a dithiolane functionality, yielding II, is also reported. For two of the alkoxy-chain-functionalized terpyridines, single-crystal x-ray crystallog. data were obtained. Finally, ordered monolayers of alkoxy-substituted terpyridines III (n = 11, 17) on highly ordered pyrolytic graphite were visualized using STM. [on SciFinder (R)

Ultrahydrophobe Modifizierung von Aluminiumoberflaechen zur Erzielung eines hohen Selbstreinigungsvermoegens Abschlussbericht

Available from TIB Hannover: F02B322+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLESaechsisches Staatsministerium fuer Wissenschaft und Kunst, Dresden (Germany)DEGerman

High Speed MAS19F NMR Analysis of an Irradiated Fluorpolymer

The effect of gamma-radiation on a perfluoroalkoxy (PFA) resin was examined using solid-state high-speed magic angle spinning (MAS) F-19 NMR spectroscopy. Samples were prepared for analysis by subjecting them to gamma-radiation in the dose range 0.5-3 MGy at either 303, 473, or 573 K. New structures identified include new saturated chain ends, short and long branches, and unsaturated groups. The formation of branched structures was found to increase with increasing irradiation temperature; however, at all temperatures the radiation chemical yield (G value) of new chain ends was greater than the G value of long branch points, suggesting that chain scission is the net process