Adolf Jesih

Air-stable monodispersed Mo6S3I6 nanowires

We report on the properties of a new air-stable nanowire material with the chemical formula Mo6S3I6 .T he distinguishing features of the material are rapid one-step synthesis, easy isolation and controllable dispersion into small-diameter wire bundles. Elemental analysis, x-ray diffraction, thermogravimetry, differential thermal analysis, Raman scattering and electron microscopy were used to characterize the material.

KrF2/MnF4 adducts from KrF2/MnF2 interaction in HF as a route to high purity MnF4

Abstract In the system KrF2—MnF2—HF two new adducts, 2KrF2·MnF4 and KrF2·MnF4 have been synthesized. The 2 : 1 adduct decomposes in a dynamic vacuum at −45°C yielding KrF2 and the 1 : 1 adduct, which is stable in a dynamic vacuum up to −25°C. KrF2·MnF4 decomposes further at room temperature to krypton, fluorine, krypton difluoride and manganese tetrafluoride. This reaction is a useful synthetic route for the preparation of pure manganese tetrafluoride.

A novel facile synthesis and characterization of molybdenum nanowires

We describe a straightforward technique to synthesize pure Mo nanowires (NWs) from Mo6SyIz (8,2 < y + z ≤ 10) NWs as precursor templates. The structural transformations occur when Mo6SyIz NWs are annealed in Ar/H2 mixture leading to the formation of pure Mo NWs with similar structures as initial morphologies. Detailed microscopic characterizations show that large diameters (>15 nm) Mo NWs are highly porous, while small diameters (<7 nm) are made of solid nanocrystalline grains. We find NW of diameter 4 nm can carry up to 30 μA current without suffering structural degradation. Moreover, NWs can be elastically deformed over several cycles without signs of plastic deformation.

A general method for the synthesis of polymeric binary flurides exemplified by AgF3, NiF4, RuF4, and OsF4

Fluride-ion capture from their anion relatives in anhydrous hydrogen fluoride solution by strong fluoride ion acceptors such as AsF5 provides a general approach to the synthesis of polymeric binary fluorides and is particularly advantageous in the synthesis of highest-oxidation-state transition metal polymeric fluorides.

On the reactions with krypton difluoride

Abstract Krypton difluoride is a more powerful oxidizing agent than elemental fluorine, in that the total bond energy of 96 kJ mole −1 , is less than that of molecular fluorine itself (155 kJ mole −1 ). Using the combination of KrF 2 with the fluoride-ion donor solvent xenon hexafluoride, it should be possible to generate salts of novel oxidation-state transition-metal fluoro-anions. With this aim, an investigation of the system MF x KrF 2 XeF 6 with MF x being AgF 2 , NIF 2 , MnF 2 , HgF 2 , FeF 2 , PdF 3 , CrF 3 etc., was commenced. During this study some new xenon(Vl) fluorometalates (e.g. XeF 5 + AgF 4 − , (Xe 2 F 11 + ) 2 NiF 2− 6 (XeF 5 + ) 2 NiF 6 2− ) were isolated and characterized, besides some already known xenon(VI) fluorometalates (e.g. XeF 5 + FeF 4 − , (Xe 2 F 11 + ) 2 MnF 6 2− , (XeF 5 + ) 2 MnF 6 2− etc.). The advantages and disadvantages of the combination KrF 2 and XeF 6 for the generation of salts with the transition metal fluoroanion in a novel oxidation state will be discussed.

NO2 gas adsorption on titania‐based nanotubes

TiO2‐based nanotubes were prepared using a hydrothermal technique and then investigated by high‐resolution TEM. Nanotubes were found to be hollow scrolls with a typical outer diameter of about 10 nm, inner diameter 4–5 nm and length of several hundred nm. The surface of nanotubes is found to be largely hydrolised. The presence of surface OH groups also determines their adsorption properties for the NO2 gas molecules. We demonstrate that TiO2 based nanotubes strongly adsorb NO2 molecules. Based on pulsed EPR experiments we suggest that the NO2 molecules couple with the nanotube surface via the nonbonding py orbital of the oxygen atoms.

A low temperature route to binary fluorides exemplified by NiF4, AgF3, RuF4, OsF4 and ReF4

Abstract The interaction between some binary fluorides and the combination of krypton difluoride and xenon hexafluoride in anhydrous hydrogen fluoride (AHF) provides an effective synthetic route to new xenon(VI) fluorometalates with each metal in a high oxidation state (e.g. (Xe 2 F + 11 ) 2 NiF 2- 6 ; (XeF + 5 AgF - 4 ). Fluoride-ion capture from such high oxidation-state-metal anions of AHF solution by strong fluoride ion acceptors (e.g. AsF 5 ) provides a general approach to the synthesis of polymeric and (in AHF) insoluble binary fluorides. This is particularly advantageous in the synthesis of thermally unstable highest-oxidation-state transition metal polymeric fluorides (e.g. NiF 4 , AgF 3 ). AgF 3 prepared in this way is a bright red diamagnetic solid apparently isostructural with AuF 3 . The hexagonal unit cells are: AgF 3 : a 0 , 5.088(10); c 0 , 15.43(3) A; V, 346 A 3 ; Auf 3 ; a 0 , 5.149(2); c 0 , 16.26 (1) A; V 373 A 3 , the AgF 3 formula unit being 4.5 A 3 smaller than for AuF 3 . These structural features imply that the d z 2 electron pair of Ag(III) is highly contracted and in conformity with its chemistry, tightly bound. Less powerfully oxidizing binary fluorides have also been made by this new approach and include RuF 4 , OsF 4 and ReF 4 , all of which have structures related to that of PdF 4 .