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Spectra tetragonal symmetry

SrTiOs undergoes a structural change from cubic to tetragonal symmetry at —110° K. Additional lines appear [619] in the fluorescence spectrum of Eu3+ doped SrTiOs, as expected due to this change in symmetry. [Pg.157]

In D4h (tetragonal) symmetry there is only one unpaired electron in two degenerate orbitals of correct symmetry to give rise to n bonds with a n orbital of the porphyrin moiety [34]. The H NMR spectrum of Fe(protoporphyrin IX)-imidazole-cyanide is reported in Fig. 5.17 [35]. The free rotation of the imidazole ring about the metal-nitrogen bond, which is fast on the NMR timescale, simulates a tetragonal symmetry as far as the chemical shifts are concerned [36]. The four methyls are all downfield, though to a quite smaller value than in the case of... [Pg.155]

In case of trigonal symmetry, the is not split. However, the orbital degeneracy is lifted by the Jahn-Teller effect which, at higher temperatures, might distort the molecular complex. At lower temperatures, the Jahn-Teller distortion in some cases goes over into a static distortion, and a spectrum due to three magnetic complexes, each with tetragonal symmetry may be observed [53]. [Pg.979]

Uranium pentafluoride prepared in the above maimer is the low-temperature, form, which can be identified by its characteristic X-ray powder pattern. The single<rystal structure has been determined tetragonal symmetry, space group I42d(Z = 8), with eight-coordination and a geometry intermediate between a dodecahedron and a square antiprism. Uranium pentafluoride is air sensitive and disproportionates in water to give a precipitate of uranium tetrafluoride and a solution of uranyl fluoride. Consequently, UFs must be handled in an inert atmosphere. The near-infrared-visible spectrum of uranium pentafluoride in acetonitrile has been determined and is perhaps the most convenient characterization. [Pg.164]

Transannular interaction via the electron-delocalization mechanism was found, but lessened by 10-15% for the ligand superhyperfine splitting and 30-35% for the hyperfine splitting (62) in the epr spectrum. The crystal structure of [VOS2CNEt2)2] shows that the molecular core has the expected C2V symmetry [V-0 = 159.1(4), V-S = 138.7(2)-241.0(2) pm] (63). Magnetic and spectral data provided evidence for a tetragonal, pyramidal structure (VII) for these complexes. Like many other coordinatively unsaturated, metal... [Pg.219]


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See also in sourсe #XX -- [ Pg.84 ]




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Symmetry tetragonal

Tetragonal

Tetragonality

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