The complex refractive index .cxa.n(.sigma.,T,.rho.) of NO2/N2O4 in the visible and static dipole polarizability of N2O4

Abstract

Dispersive Fourier transform spectroscopy in the visible (DFTS-VIS) is used to study the complex refractive index A of equilibrium mixtures of N O D 2 0 4 in the gas phase between 290 and 350 K and in the wavenumber range between 11 000 and 19 000 cm-'. With the aid of quantum-chemical MBPTMP2 calculations of the components of the static dipole polarizability tensor of N2O4, the quasi-continuous spectra of the complex mean dipole polarizability = a -ia' of the neat components NO2 and N204 are obtained. On the other hand, for these neat components a(uo) at wavenumber 00 = 15 798 cm-' is experimentally determined to be ano,(uo) = 3.0233(37) x m3 and aN,o,(uo) = 6.69(13) x m3. The static limit of the mean dipole polarizability a of N204 is calculated to be a(0) = 6.43(19) x m3. In addition, we report experimental results on the equilibrium constant Kp of the dimerization equilibrium N204 === 2N02, obtained from the temperature and pressure dependence of iz, as well as quantum-chemical calculations of the quadrupole and hexadecapole moment tensors of N2O4.

Electrooptical Properties and Molecular Polarization of Iodine, I2

“…The interferometric experiments are performed with an evacuated Michelson twin interferometer, which has been used before for the determination of the electrooptical properties of NO 2 /N 2 O 4 , Zn, Cd, and Hg . We measured the complex refractive index n̂ (σ, p , T ) = n (σ) − ia (σ)/(4πσ) (σ = 1/λ = wavenumber, a (σ) = absorption coefficient of Lambert−Beer's law) at three discrete wavenumbers σ 1 = 15 798.0 cm -1 , σ 2 = 16 832.3 cm -1 , and σ 3 = 30 756.9 cm -1 , using laser as radiation sources.…”

Dipole Polarizability, Cauchy Moments, and Related Properties of Hg

“…This relative spectrum is fixed to the refractivities measured at λ 1 and λ 2 . More details of the experimental procedure can be found in ref , where we have examined the complex refractive index of NO 2 /N 2 O 4 and in refs and , where the dipole polarizability of Cd has been obtained by interferometric high-temperature measurements.…”

“…The measurements of [ n (λ,ρ) − 1] were performed at three different wavelengths between 632.99 and 325.13 nm using a traditional interferometric technique. Additionally, we have recorded quasi-continuous refractive index spectra of Hg vapor via dispersive Fourier transform spectroscopy (DFTS) , in the visible wavenumber range.…”

Determination of the Complete Polarizability Tensor of 1,3-Butadiene by Combination of Refractive Index and Light Scattering Measurements and Accurate Quantum Chemical ab Initio Calculations

“…The calculation of the dipole polarizability of butadiene in this paper relies on the finite-field method . More detailed descriptions of our method and emphasis on the computational aspects may be found in previous work. − The energy of an uncharged molecule in a homogeneous electric field can be written as , where E 0 is the energy of the unperturbed molecule, F α the field at the origin, and μ α , α αβ , β αβγ , and γ αβγδ the dipole moment, polarizability, and dipole hyperpolarizabilities (the repeated Greek subscript implies summation over the Cartesian coordinates x , y , and z ). For molecules with C 2 h ( trans -1,3-butadiene) symmetry the dipole polarizability tensor α αβ has four independent components and for C 2 v symmetry ( cis -1,3-butadiene) three .…”