Spectre infrarouge à l'état solide des molécules isotopiques de SO2

High-pressure vibrational spectroscopy of sulfur dioxide

“…Further, the IR mode has a significantly higher frequency ͑552 cm −1 ͒ than found at ambient pressure. 9 All these observations are consistent with those for v 1 .…”

“…This involves comparison of our Raman and IR data with results obtained at ambient pressure. 6,7,9 For this purpose, we extrapolated the frequencies of all the observed optical modes to zero pressure. The extrapolated values are given in parentheses in Table I.…”

“…1 Its vibrational, rotational, and electronic structures have been widely investigated both experimentally and theoretically in gas phase ͑i.e., ambient conditions͒. [2][3][4][5][6][7][8][9] The isolated molecule has a C 2v symmetry and its three fundamental vibrational modes, i.e., v 1 ͑A 1 , Sv O symmetric stretch͒, v 2 ͑A 1 O v S v O deformation͒, and v 3 ͑B 1 , Sv O asymmetric stretch͒, are all both infrared and Raman active. Sulfur dioxide condenses at 263 K and freezes at 198 K. The crystal structure of SO 2 has been determined by Post et al 10 using single-crystal x-ray diffraction at 143 K. Solid SO 2 has an orthorhombic structure with four molecules per unit cell with space group Aba ͑C 2v 17 ͒ and cell parameters a = 6.07 Å, b = 5.94 Å, and c = 6.14 Å, yielding a cell volume of 221 Å 3 and density of 1.92 g / cm −3 .…”

A systematic mid-infrared spectroscopic study of thermally processed SO2 ices

“…Thermal annealing of a low temperature amorphous SO 2 ice results in its crystallisation at temperatures above 70 K, resulting in a narrowing of the stretching mode bands and the development of band sub-structures attributable to various SO 2 isotopologues and the LO-TO splitting † of the 32 S 16 O 2 bands. [44][45][46] Other mid-infrared spectroscopic studies have also been performed with the aim of characterising higher frequency overtone and combination bands 47,48 or the structure of the SO 2 dimer. 49,50 In order to better detect the presence of SO 2 ice in various astronomical environments and assess its thermal history, systematic and quantitative laboratory studies of its midinfrared spectroscopy under different deposition and thermal annealing conditions are required.…”

Estudo espectroscópico dos produtos de reação entre algumas aminas heterocíclicas alifáticas e dióxido de enxofre

“…Também a região compreendida entre 1250 -1000 em-I, onde ocorre o modo de estiramento simétrico do S02, livre ou ligado, apresenta-se na forma de uma banda larga, dificultando a localização das frequências correspondentes que, no entanto, são prontamente verificadas por meio dos espectros Raman. É notável a ausência do intenso estiramento anti-simétrico do S02, usualmente em 1315 cin-1 (sólido) [24], possivelmente devido ao deslocamento para frequências mais baixas, localizando-se na região acima descrita.…”