Luminescent and thermochromic properties of tellurium(IV) halide complexes with cesium

The spectral-luminescent and thermochromic properties of complex compounds of the composition Cs(2)TeHal(6) (Hal = Cl, Br, I) are studied. The interrelation between the geometric structure and spectral-luminescent properties is studied using the example on complex compounds of tellurium(IV) halides with cesium. The Stokes shift and the luminescence intensity of D cent e(IV) ions with island octahedral coordination are found to depend on the position of the A band in the luminescence excitation spectra, the diffuse reflection, and the energy of the luminescent (3) P (1) -> (1) S (0) transition of the tellurium(IV) ion. The maximum luminescence intensity and the minimum Stokes shift at 77 and 300 K are observed for Cs(2)TeDl(6). The geometrical and electronic factors responsible for luminescence intensification in Te(IV) complexes under study are analyzed.