Detection of single atoms and buried defects in three dimensions by aberration-corrected electron microscope with 0.5-a information limit

The ability of electron microscopes to analyze all the atoms in individual nanostructures is limited by lens aberrations. However, recent advances in aberration-correcting electron optics have led to greatly enhanced instrument performance and new techniques of electron microscopy. The development of an ultrastable electron microscope with aberration-correcting optics and a monochromated high-brightness source has significantly improved instrument resolution and contrast. In the present work, we report information transfer beyond 50 pm and show images of single gold atoms with a signal-to-noise ratio as large as 10. The instrument's new capabilities were exploited to detect a buried Sigma3 {112} grain boundary and observe the dynamic arrangements of single atoms and atom pairs with sub-angstrom resolution. These results mark an important step toward meeting the challenge of determining the three-dimensional atomic-scale structure of nanomaterials.     

Zur Bestimmung Thermodynamischer Komplexstabilitätskonstanten in Dioxan-Wasser-Mischung

On the determination of coordination stability constants in dioxane-water mixture. The potentiometric method of determining thermodynamic acid constants and coordination stability constants in dioxane—water mixture is critically examined and the necessary values for mean molal activity coefficients and pH meter correction are reascertained.     

Simultaneous Thermogravimetry and Differential Thermal Analysis of Non-Oxo Vanadium(IV) Chelates with Tridentate Diacidic Ligands

The TG and DTA curves of non-oxo vanadium(IV) chelates with tridentate diacidic li-gands were recorded. The ligands contain the donor set O^∩N^∩O(S) and belong in the groups of dihydroxy azo- or azomethine compounds, and of β-dicarbonyl (salicyl) benzoyl (salicyl)hy-drazones. The onset temperatures, the mass defects and the reaction rates were calculated.     

Ligandeneigenschaften von Thiopyronen. I. Metallchelate von 2-Methyl-3-hydroxy-4-thiopyron (Thiomaltol)

Coordination Ability of Thiopyrones. I. Metal Chelates of 2-Methyl-3-hydroxy-4-thiopyrone (Thiomaltol) Metal chelates of 2-methyl-3-hydroxy-4-thiopyrone with a series of metals are prepared as solids, the constitution of the complexes is determined in solution, and the extraction ability of the ligand for copper, nickel, cobalt and palladium is studied. Stability constants of the zinc and cadmium chelates are compared with those of thiodibenzoyl-methane.     

Ligandenaustauschreaktionen von Bis(acetylacetonato)dioxo-molybdän(VI). Kristallstrukturen von [Salicylaldehyd-benzoylhydrazonato(2–)]dioxo-methanol-molybdän(VI) und [Benzoylaceton-benzoylhydrazonato(2–)] dioxo-triphenylphosphanoxid-molybdän(VI)

Ligand Exchange Reactions of Bis(acetylacetonato)dioxo-molybdenum(VI). Crystal Structures of [Salicylaldehyde-benzoylhydrazonato(2–)]dioxo-methanol-molybdenum(VI) and [Benzoylacetone-benzoylhydrazonato(2–)]dioxo-triphenylphosphaneoxide-molybdenum(VI) The products of ligand exchange reactions between bis(acetylacetonato)dioxo-molybdenum(VI) and tridentate diacidic ligands H₂L in the presence of triphenylphosphane were found by mass spectrometry to be complexes of the type MoO₂L. In the case of salicylaldehyde 2-hydroxyanil MoL₂ could also be identified. The compounds MoO₂L were crystallized as complexes with methanol or triphenylphosphane oxide. Crystallographic data see “Inhaltsübersicht”.     

EPR-Untersuchungen an Vanadylkomplexen

EPR Examination of Vanadyl Complexes For a series of bidentate ligands the reaction with VOSO₄ · 3 H₂O was studied in homogeneous solution. The resulting complexes were examined by EPR spectroscopy in chloroform at T = 295 and 133 K to receive evidence of the redox behavior of the compounds and of bonding relations in the first coordination sphere in dependence on the equatorial donor atoms.     

Reaktionen und thermisches Verhalten oxofreier Vanadium(IV)-Komplexe. Kristallstrukturen von Methoxo-oxo[thenoyltrifluoraceton-salicylhydrazonato(2−)]vanadium(V) und Methoxo-oxo[benzoylaceton-salicylhydrazonato(2−)]vanadium(V)

Reactions and Thermal Behaviour of Nonoxo Vanadium(IV) Complexes. Crystal Structures of Methoxo-oxo[thenoyltrifluoroacetone-salicylhydrazonato(2–)]vanadium(V) and Methoxo-oxo[benzoylacetone-salicylhydrazonato(2–)]vanadium(V) The persistence of non-oxo vanadium(IV) complexes in dichlormethane/methanol/water solutions was studied by UV/VIS spectroscopy. The reaction products methoxo-oxo-[thenoyltrifluoroacetone-salicylhydrazonato(2–)]vanadium(V) and methoxo-oxo[benzoylacetone-salicylhydrazonato(2–)]vanadium(V) were isolated and characterized by X-ray analysis. The thermal behaviour of non-oxo vanadium(IV) complexes was checked.     

Chelate von Chinolin-8-ol-Derivaten. VIII. Säure- und Komplexstabilitätskonstanten alkyl- bzw. alkenylsubstituierter Chinolin-8-ole

Chelates of 8-Quinolinol Derivatives. VIII. Acid and Complex Stability Constants of Alkyl and Alkenyl Substituted 8-Quinolinols For a series of 7-substituted alkyl and alkenyl 8-quinolinols as well as 2-, 5-, and 7-methyl-8-quinolinols the acid constants and the stability constants of the nickel and zinc chelates were determined potentiometrically in 75 vol-% dioxane-water mixture. Methyl groups, as expected, increase the basicity of both donor atoms of the 8-quinolinols, whereas alkyl substituents in 7-position cause a decrease in basicity of the quinoline N-atom. The influence of substituents on the complex stability is only small.     

Komplexe von Vanadium und Titan mit 2,2′-Dihydroxyazobenzen. Kristallstrukturen von 2,2′-Dihydroxyazobenzenato(2-)-oxo-methoxo-methanol-vanadium(V) und μ-Oxo-bis[2,2′-dihydroxyazobenzenato(2-)-oxo-vanadium(V)]

Complexes of Vanadium and Titanium with 2,2′-Dihydroxyazobenzene. Crystal Structure of 2,2′-Dihydroxybenzenato(2-)-oxo-methoxo-methanol-vanadium(V) and μ-Oxo-bis[2,2′-dihydroxyazobenzenato(2-)-oxo-vanadium(V)] By the reaction of 2,2-dihydroxyazobenzene with titanium(IV) the expected compound bis [2,2′-dihydroxybenzenato(2-)-titanium(IV)] was obtained. On the other hand in the dependence on the experimental conditions vanadium forms further compounds beside the bisligand complex. They were characterized by mass spectrometry resp. X-ray structural analysis. Crystallographic data see ?Inhaltsübersicht”?.