Rotational Raman intensities and the measured change with internuclear distance of the polarizability anisotropy of H/sub 2/, D/sub 2/, N/sub 2/, O/sub 2/, and CO

Journal Article · Fri Feb 15 04:00:00 EST 1980 · J. Chem. Phys.; (United States)

OSTI ID:5555353

Asawaroengchai, C; Rosenblatt, G M

The relative intensities of O and S branch lines in the v=1reverse arrowv=0 Stokes Raman spectrum of gaseous H/sub 2/, D/sub 2/, N/sub 2/, O/sub 2/, and CO have been measured in order to obtain a parameter chi= (..cap alpha../sub parallel/-..cap alpha../sub perpendicular/)/sub e//)r/sub e/(partial (..cap alpha../sub parallel/-..cap alpha../sub perpendicular/)/partialr)/sub e/). Values for chi reflect the detailed molecular electronic structure and are needed in various scattering theories and to correct rotational and vibrational--rotational Raman intensities for molecular nonrigidity and vibrational-rotational interaction. The values of chi obtained are +0.38 +- 0.01 (H/sub 2/), +0.38 +- 0.01 (D/sub 2/), +0.45 +- 0.09 (N/sub 2/), +0.23 +- 0.07 (O/sub 2/), and +0.27 +- 0.13 (CO). By combining the measured values of chi with experimental values for <..cap alpha../sub parallel/-..cap alpha../sub perpendicular/>/sub v/=0 in the literature, the following values of the polarizability anisotropy and its first derivative at r/sub e/ are obtained: (..cap alpha../sub parallel/-..cap alpha../sub perpendicular/)/sub e/=0.288 (H/sub 2/), 0.282 (D/sub 2/), 0.691 (N/sub 2/), 1.080 (O/sub 2/), and 0.525 (CO) A/sup 3/; (partial (..cap alpha../sub parallel/-..cap alpha../sub perpendicular/)/partialr)/sub e/=1.02 (H/sub 2/), 1.00 (D/sub 2/), 1.40 (N/sub 2/) 3.89 (O/sub 2/), and 1.72 (CO) A/sup 2/. These values are compared with literature theoretical values. Molecular polarizability is an experimentally accessible quantity which reflects in a rather direct way the electronic structure of simple molecules. For this reason the orientational anisotropy of molecular polarizability and its variation with internuclear distance are of fundamental interest in developing understanding of the detailed electronic structure of diatomic molecules. Polarizability anistropies and their derivatives are directly related to both absolute and relative intensities of vibrational and rotational Raman transitions.

• Research Organization: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
• OSTI ID: 5555353
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 72:4; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular &amp; Chemical Physics-- Atomic &amp; Molecular Properties &amp; Theory
74 ATOMIC AND MOLECULAR PHYSICS
ANISOTROPY
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CRYOGENIC FLUIDS
DEUTERIUM
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
FLUIDS
HYDROGEN
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
NITROGEN
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLARIZABILITY
RAMAN SPECTRA
ROTATIONAL STATES
SPECTRA
STABLE ISOTOPES