Synthesis of electro-active compounds suitable for adsorption on metal surfaces

PostprintPeer reviewe

Regioselective bromination of 1,4-dimethoxy-2,3-dimethylbenzene and conversion into sulfur-functionalised benzoquinones

The NBS bromination of 1,4-dimethoxy-2,3-dimethylbenzene has been examined under a variety of conditions in both 1,1,1-trichloroethane and benzotrifluoride. Four different bromination products have been isolated including the previously unknown 1-bromo-4-bromomethyl-2,5-dimethoxy-3-methylbenzene whose single crystal X-ray structure is presented. The synthetically useful 2,3-bis(bromomethyl)-1,4-dimethoxybenzene is readily prepared using either solvent and it has been converted into new sulfur-containing quinone derivativesPostprintPeer reviewe

Synthesis and adsorption of dihydro-tetrathiafulvalene derivatives on gold surfaces

Three norbornane fused dihydro-tetrathiafulvalene derivatives which contained the thiol, disulfide and acetylthio functionalities were synthesised. Cyclic voltammetry was used to measure the redox properties of the compounds, which showed that the molecules were able to undergo two reversible, one electron oxidation processes. X-ray structures of all three functionalities were obtained. The three compounds were sublimed onto Au(111) surfaces, and characterised using a number of surface science techniques. Disordered structures are formed initially for all three compounds when adsorbed at room temperature. Following progressive annealing of the substrate, highly ordered adlayer structures are formed that are believed to be bound to the surface via a gold adatom. Van der Waals and hydrogen bonding interactions are shown to play an important role in the formation of these ordered structures. The adsorption of triphenylphosphine sulfide on Au(111) is also investigated, using a combination of RAIRS and STM experiments. Here an extremely ordered (2√3×2√3)R30º structure is formed immediately upon deposition at 298 K. From the experimental data and DFT calculations, the orientation of the molecule is deduced. The attempted synthesis of a thiol functionalised donor-acceptor compound is also described, with a few previously unknown intermediate compounds being synthesised. Finally, a series of four known aryl amidoximes were synthesised. These were subsequently deposited on a Cu(111) crystal and studied using a vibrational spectroscopy. Three of the compounds were found to decompose to varying degrees during the sublimation process. The possible conformations of the amidoxime group on the copper surface are discussed

Regioselective bromination of 1,4-dimethoxy-2,3-dimethylbenzene and conversion into sulfur-functionalised benzoquinones

The NBS bromination of 1,4-dimethoxy-2,3-dimethylbenzene has been examined under a variety of conditions in both 1,1,1-trichloroethane and benzotrifluoride. Four different bromination products have been isolated including the previously unknown 1-bromo-4-bromomethyl-2,5-dimethoxy-3-methylbenzene whose single crystal X-ray structure is presented. The synthetically useful 2,3-bis(bromomethyl)-1,4-dimethoxybenzene is readily prepared using either solvent and it has been converted into new sulfur-containing quinone derivative

A Comparison between BTA and Amidoximes and their Interactions with Copper Surfaces

The use of integration of copper interconnects in semiconductor devices has greatly advanced the development of integrated circuits and has enabled ever higher device densities. Unfortunately the oxides of copper are poorly suited to semiconductor manufacture. As Cu (I) and Cu (II) oxides are not self-limiting they can pose serious issues from a cleaning and queue time management perspective. In both post-etch and post-CMP cleaning applications it is critical that both types of Cu oxide are removed without damage to either Cu or the dielectric. With the most advanced sub 32nm nodes simply removing the oxides is not sufficient; their re-growth must also be prevented using surface passivation

Adsorption of a dihydro-TTF derivative on Au(111) via a thiolate bonding complex to gold adatoms

Funding: Scottish GovernmentA dihydro-TTF derivative with four acetyl-protected thiol ligands was synthesised and adsorbed on Au(111) under UHV conditions. Scanning Tunnelling Microscopy (STM) and Infrared (IR) spectroscopy show that self-organised structures are formed following annealing to 333 K, with each pair of bidentate thiolate ligands bonding to a single gold adatom in a S–Auad–S complex. Due to the lack of a direct orbital overlap between the dihydro-TTF moieties and the surface, relatively little charge transfer between TAT-TTF and the gold surface occurs.Publisher PDFPeer reviewe