Evaluation of photostability of solid-state dimethyl 1,4-dihydro-2,6-dimethyl-4-(2-nitro-phenyl)-3,5-pyridinedicarboxylate by using Fourier-transformed reflection-absorption infrared spectroscopy

1999 ◽  
Vol 184 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Reiko Teraoka ◽  
Makoto Otsuka ◽  
Yoshihisa Matsuda
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Reflection Absorption Infrared Spectroscopy

Synthèse et caractérisation des oxypentafluorouranates(VI) NH4UOF5, KUOF5, RbUOF5 et CsUOF5

1978 ◽  
Vol 56 (14) ◽  
pp. 1874-1880 ◽  
Author(s):  
Philippe Joubert ◽  
Roland Bougon ◽  
Bernard Gaudreau
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Alkali Metal ◽  
Vibrational Spectroscopy ◽  
Uranium Atom ◽  
The Other ◽  
Metal Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

The oxypentafluorouranates(VI) MUOF5, where M = NH4, K, Rb, Cs, have been synthetized from reaction of UOF4 with the ammonium or corresponding alkali metal fluoride in liquid SO2. According to X-ray diffraction, Raman and infrared spectroscopy, and from an isomorphism with the corresponding hexafluorouranates(V) MUF6, two different environments around the uranium atom are observed. In CsUOF5 the five fluorine atoms and the oxygen around the uranium result in a pseudo-octahedral surrounding whereas for the other complexes (M = NH4, K, Rb) each uranium is surrounded by eight light atoms forming a dodecahedron. In this structure the dodecahedra are linked together by fluorine atoms to form infinite chains. The UOF5− ion has been characterized by vibrational spectroscopy in the solid state. The proposed assignment, which was made with the assumption of a C4v symmetry of the UOF5− ion, was confirmed by a force constant calculation. From these data and contrary to the values reported for comparable oxypentafluoroanions, the axial fluorine is found to be less ionic than the equatorial ones.

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