Die IR‐Spektren der Oxofluorokomplexe TiOF, VOF, NbO₂F, MoO₃F und WO₃F

Abstract

Die IR‐Spektren einiger im Elpasolith‐Typ kristallisierender Alkali‐Oxofluorokomplexe vom Typ A2A′TiOF5, A2A′VOF5, A2A′NbO2F4, A2A′MoO3F3 und A2A′WO3F3 (A = großes Alkalimetall, A′ = kleines Alkalimetall) werden mitgeteilt und zugeordnet. Danach besitzen TiOF 53− und VOF 53− die Symmetrie C4v, während NbO2F 43− (cis) sowie MoO3F 33− und WO3F 33− (trans) der Punktgruppe C2v angehören. Für K2NaWO3F3 wird zusätzlich das RAMAN‐Spektrum angegeben.

The crystal structure of K2VO2F3, a nonlinear dioxovanadium(V) group

“…3 is a stereo view down the vector (0.0, 0.9848, 0.1737) showing the packing of these chains in the unit cell. This anionic chain structure differs from the models proposed by Davidovich, Sergienko & Murzakhanova (1968) and Pausewang & Dehnicke (1969) in that the vanadium polyhedra are linked by cis rather than trans bridging fluorine atoms. Cis fluorine bridging also occurs in Group V B and VI B pentafluorides and oxytetrafluorides (Edwards, Peacock & Small, 1962;Edwards, 1964;Edwards & Steventon, 1968;Edwards, Jones & Sills, 1968;Edwards & Jones, 1969;Edwards, 1969).…”

“…Table 4 gives the observed absorption maxima in both the Raman and the infrared spectra of the compound. In the region examined, our infrared spectrum agrees essentially with that reported by Pausewang & Dehnicke (1969). The coincidence of the Raman and infrared bands at ca.…”

“…H20 has also been reported (Grandjean & Weiss, 1967), but Pinsker & Kuznetsov (1968) have reported a linear O-Mo-O group in the corresponding anhydrous salt, and Markin (1968) has proposed a linear O-V-O group in (NH4)3VO2F4. Recent infrared investigations (Davidovich, Sergienko & Murzakhanova, 1968;Pausewang & Dehnicke, 1969) of the related compound KzVO2F3 (Petersen, 1889) have led to the postulate that this anion also contains a cis dioxo group. The anion was also presumed to be polymeric in the solid, although several models were proposed.…”

Raman spectroscopic study of the lattice dynamics in the Rb2KMoO3F3 oxyfluoride

“…A 2 A'MO 3 F 3 oxyfluorides differ from pure oxides and fluorides by a lower (noncubic) symmetry of the six coordinated anion (quasi octahedron). According to the fac and mer configurations of arrangement of ligands, the symmetry can be trigonal (C 3v ) or orthorhombic (C 2v ), respectively [2]. Because of the difference in the magnitudes of the F and O charges, each of the configurations must necessarily have a dipole moment.…”

A study of phase transition in (NH4)3WO3F3 oxyfluoride by Raman scattering

“…According to [2], mixed A 3 BO x Hal (6-x) compounds (x depends on A and B valences) retain the same cubic symmetry of the-high symmetry phase (see Fig. 1); oxygen and halogen ions are distributed statistically over the crystal lattice and the local symmetry of BО x Hal (6-x) octahedra is lower than the cubic one [3,4].…”