BrF 5 can be prepared by treating BrF 3 with fluorine under UV light in the region of 300 to 400 nm at room temperature. It was analyzed by UV-Vis, NMR, IR and Raman spectroscopy. Its crystal structure was redetermined by X-ray diffraction, and its space group was corrected to Pnma. Quantum-chemical calculations were performed for the band assignment of the vibrational spectra. A monoclinic polymorph of BrF 5 was quantum chemically predicted and then observed as its low-temperature modification in space group P2 1 /c by single crystal X-ray diffraction. BrF 5 reacts with the alkali metal fluorides AF (A = K, Rb) to form alkali metal hexafluoridobromates(V), A[BrF 6 ] the crystal structures of which have been determined. Both compounds crystallize in the K[AsF 6 ] structure type (R � 3, no. 148, hR24). For the species [BrF 6 ] + , BrF 5 , [BrF 6 ] À , and [IF 6 ] À , the chemical bonds and lone pairs on the heavy atoms were investigated by means of intrinsic bond orbital analysis.

The HKLF5Tools program provides useful tools for structure refinement against non-merohedrally twinned datasets. The software shows statistical information on each twin component, can delete or rename twin components, merge reflection data, and add an inversion twin component to any of the existing twin components. Also, the software can convert ShelXL FCF files into HKL reflection files so that refinement against detwinned data in the final stages of the refinement becomes possible.

The significant similarity between MF 3 , MF 4 -, and M 2 F 7 -(M = Au, Br) is studied using quantum chemical methods. It is expected that compounds containing Au 3 F 10 anions are likely to be stable. A theoretical background for the ongoing attempts of their synthesis is provided by calculations on the stabilities and molecular struc-

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Der 3d‐Metall‐vermittelte Nitrentransfer ist Gegenstand intensiver Forschung aufgrund seines Potentials als atomökonomischer und umweltfreundlicher Ansatz zur direkten Aminierung (un)funktionalisierter C‐H‐Bindungen. Wir berichten nun über die Isolierung und Charakterisierung eines selten trigonalen Imidocobalt(III)‐Komplexes mit einer sehr langen Cobalt‐Imid‐Bindung. Er kann auf intermolekularer Weise, präzedenzlos für Imidocobaltkomplexe, starke C‐H‐Bindungen mit einer Bindungsdissoziationsenergie von bis zu 92 kcal mol−1 spalten. Dies resultiert in dem Amidocobalt(II)‐Komplex [Co(hmds)2(NHtBu)]−. Kinetische Studien diesbezüglich deuten auf einen H‐Atomtransfer‐Mechanismus. Erstaunlicherweise ist das Cobalt(II)amid in Abhängigkeit des Substrats auch in der Lage, die H‐Atomabstraktion oder einen schrittweisen Protonen‐/Elektronentransfer durchzuführen. Eine cobaltkatalysierte Substratdehydrogenierung unter Verwendung eines Organoazids wird gezeigt.