TY - JOUR

T1 - Distortions in IR Spectra Related to Registration Conditions

T2 - II. The Influence of Scattering

AU - Novikov, R. G.

AU - Konopnitskii, R.

AU - Tsyganenko, A. A.

PY - 2018/5/1

Y1 - 2018/5/1

N2 - We consider distortions of the shapes of absorption bands of strongly scattering samples in the spectra of molecules adsorbed on the surface of dispersed solids. We show that the influence of the scattering on IR spectra of dispersed samples is not reduced merely to a weakening of the intensity of the transmitted light, but, rather, the scattering affects the contour of a spectral band due to changes in the refractive index of the substance in the range of the absorption band. Using carbon dioxide adsorbed on a NaX zeolite as an example, we demonstrate two methods for taking into account the contribution of the scattering to the spectra of surface compounds: the registration of the “diffuse-transmission” spectrum and placing a sample into an immersion liquid, for which liquid oxygen is used. The obtained spectra indicate that, if the zeolite is saturated with the adsorbate, the band of the antisymmetric stretching vibration of CO2 molecules broadens and reveals a complex structure as a result of the resonant dipole–dipole interaction between adsorbed molecules.

AB - We consider distortions of the shapes of absorption bands of strongly scattering samples in the spectra of molecules adsorbed on the surface of dispersed solids. We show that the influence of the scattering on IR spectra of dispersed samples is not reduced merely to a weakening of the intensity of the transmitted light, but, rather, the scattering affects the contour of a spectral band due to changes in the refractive index of the substance in the range of the absorption band. Using carbon dioxide adsorbed on a NaX zeolite as an example, we demonstrate two methods for taking into account the contribution of the scattering to the spectra of surface compounds: the registration of the “diffuse-transmission” spectrum and placing a sample into an immersion liquid, for which liquid oxygen is used. The obtained spectra indicate that, if the zeolite is saturated with the adsorbate, the band of the antisymmetric stretching vibration of CO2 molecules broadens and reveals a complex structure as a result of the resonant dipole–dipole interaction between adsorbed molecules.

UR - http://www.scopus.com/inward/record.url?scp=85049174073&partnerID=8YFLogxK

U2 - 10.1134/S0030400X18050156

DO - 10.1134/S0030400X18050156

M3 - Article

AN - SCOPUS:85049174073

VL - 124

SP - 655

EP - 659

JO - OPTICS AND SPECTROSCOPY

JF - OPTICS AND SPECTROSCOPY

SN - 0030-400X

IS - 5

ER -