No abstract

We report a new method for electrodeposition of device-quality metal chalcogenide semiconductor thin films and nanostructures from a single, highly tuneable, non-aqueous electrolyte. This method opens up the prospect of electrochemical preparation of a wide range of functional semiconducting metal chalcogenide alloys that have applications in various nano-technology areas, ranging from the electronics industry to thermoelectric devices and photovoltaic materials. The functional operation of the new method is demonstrated by means of its application to deposit the technologically important ternary Ge/Sb/Te alloy, GST-225, for fabrication of nanostructured phase change memory (PCM) devices and the quality of the material is confirmed by phase cycling via electrical pulsed switching of both the nano-cells and thin films.

The synthesis and characterization by single-crystal X-ray diffraction of two thallium salts of the non-co-ordinating anion [B{3,5-(CF3)2C6H3}4] are reported. They possess Tl-Tl contacts supported by Tl-aryl interaction. This cation association overcomes both electrostatic repulsion and cation-anion size and charge matching considerations in the [LTl2L](2+) dications so formed.

Highly unusual Na + complexes with neutral tri-and tetra-amines are isolable in good yield from the reaction of NaBAr F with the amine in organic media. Structural characterisation reveals primary Na-N bonding, including an unusual sandwich cation [Na(Me 3 tacn) 2 ] + , derived from homoleptic N 6 -coordination via two Me 3 -tacn ligands, and the distorted 5-coordinate [Na(thf)(Me 4 cyclam)] + .Scheme 1 Unexpected formation of 1 from the attempted use of NaBAr F as a halide abstractor. B = remainder of [BAr F ] À anion (omitted for clarity).

Reaction of imidoyl chlorides Ar*N=CClR (Ar* = 2‐iPrC6H4, 2,6‐iPr2C6H3, 2‐MeOC6H4; R = Me, Ph, tBu) with [Li(nacnac)] [nacnac = (Ar*NCMe)2CH] gives β‐triketimines L, most of which exist in solution in equilibrium with their imine/enamine tautomers. The route is highly modular, allowing independent variation of at least five parameters. The solution equilibria are very sensitive to such substituent pattern variation. Single‐crystal X‐ray diffraction analyses of examples of both tautomers and a geometric isomer in the solid state are presented, alongside solution NMR studies of the tautomerism. All examples revert exclusively to the β‐triimine form on complexation with M(CO)3 fragments (M = Cr, Mo, W). Facial isomers result. The ligands are weak σ‐donors, as adjudged by CO IR stretching frequencies in [LM(CO)3]. Crystal‐structure determination on the isostructural pair [HC(2‐iPrC6H4N=CMe)3M(CO)3] (M = Cr, Mo) revealed a hexagonal packing arrangement composed of aryl–aryl and carbonyl (CO)–H–C interactions which generates pseudocylindrical voids accounting for 6–9 % of the crystal volume. In only one case were these occupied by solvent molecules. This family of facially capping N,N,N‐ligands with finely tunable bulk have wide potential in coordination chemistry.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)