Die Struktur des Selentetrafluorid in Lösung

The Structure of Selenium Tetrafluoride in Solution The fluorine exchange in selenium tetrafluoride is suppressed at ?140°C in solution of methylfluoride. SeF₄ is a monomer species under these conditions.     

Bestimmung der Struktur von Phenyläthinyllithium in Lösung mittels Tieftemperatur-NMR-Spektroskopie

The dimeric and tetrametic structures of complexes of phenylethinyllithium, as recently discovered by X-ray analysis in the solid state, were also found to be present in solution. Tetrahydrofuran solutions of 1-(⁶Li)-[1-¹³C]-2-phenylethyne in the presence or absence of N,N,N′,N′-tetramethylpolymethylenediamines show a pentuplett ¹³C-NMR signal [δ=140 ppm, J(C,Li)=8.2 Hz] from the labelled C-atom at low temperatures (?95 to ?110°). This proves the dimeric structure. When (⁶Li)BuLi is added, a mixed dimer [(C₆H₅C?CLi)(C₄H₉Li)] is formed [δ=142 ppm, J(C,Li) = 7.8 Hz]. This is converted to a mixed tetramer [(C₆H₅C?CLi)(C₄H₉Li)₃] upon addition of larger amounts of (⁶Li)BuLi, as concluded from a signal at δ = 133.5 ppm, J(C,Li) = 5.6 Hz. The multiplicity of this signal suggests that a static tetramer is present, in which the C-atoms couple only with three next Li-neighbors.     

Einlagerungsreaktionen von Biscyclopentadienyl-Vanadium und -Mangan mit Eisenoxidchlorid in etherischer Lösung

Intercalation Compounds of Manganocene and Vanadocene with FeOCl in Ether Solution The recently synthesized FeOCl intercalation compounds from Cp₂Mn and Cp₂V proved that in the case of the vanadium compounds the Fe³⁺ centers of the FeOCL host-lattice were partly reduced to Fe₂₊. In comparison to the bulk FeOCl, the central doublet in the Mößbauer spectra of the FeOCl intercalation compounds with NH₃, pyridine, 4-amino-pyridine, manganese and vanadium compounds indicates – with respect to the biscyclopentadienyl transition metal FeOCl intercalation compounds (M = Cr, Fe, Ni, Co) – a small chemical shift to higher energies and a degradation of the quadrupol splitting.     

Stabilisierung von Cer(IV) in Lösung mittels Komplexonen

By means of spectrophotometric methods the interaction of Ce^IV in sulphate and nitrate containing solutions with diethylenetriaminepentaacetic acid (DTPE, H₅L), ethylenetriaminetetraacetic acid (ÄDTE, H₄A), nitrilotriacetic acid (NTE, H₃X), iminodiacetic acid (IMDE, H₂Z), acids, and glycine (HGL) has been investigated. In weakly acidic acid redox-stable Ce^IV complexomates are formed with DTPE, ÄDTE and NTE; Ce^IV reduction proceeds the more slowly, the more stable the complexonate is. The reverse holds for strongly acidic solutions. Inorganic anions in the solutions display a strong influence on composition and redoxactivity of the Ce^IV complexonates. The stability of Ce^IV in its complexonates depends on the type of metal-ligand bonding.