Publication
Reference
Moore Marla H., Ferrante Robert F., Moore W. James, Hudson Reggie (2010). Infrared Spectra and Optical Constants of Nitrile Ices Relevant to Titan's Atmosphere. Astrophys. J., Suppl. Ser., 191, 96 - 112.
Names
  • Marla H. Moore
  • Robert F. Ferrante
  • W. James Moore
  • Reggie Hudson
Article and keywords
Title
Infrared Spectra and Optical Constants of Nitrile Ices Relevant to Titan's Atmosphere
Abstract
Spectra and optical constants of nitrile ices known or suspected to be in Titan's atmosphere are presented from 2.0 to 333.3μm (~5000-30 cm$^{-1}$). These results are relevant to the ongoing modeling of Cassini CIRS observations of Titan's winter pole. Ices studied are: HCN, hydrogen cyanide; C$_2$N$_2$, cyanogen; CH$_3$CN, acetonitrile; C$_2$H$_5$CN, propionitrile; and HC$_3$N, cyanoacetylene. For each of these molecules, we also report new cryogenic measurements of the real refractive index, n, determined in both the amorphous and crystalline phases at 670 nm. These new values have been incorporated into our optical constant calculations. Spectra were measured and optical constants were calculated for each nitrile at a variety of temperatures, including, but not limited to, 20, 35, 50, 75, 95, and 110 K, in both the amorphous phase and the crystalline phase. This laboratory effort used a dedicated FTIR spectrometer to record transmission spectra of thin-film ice samples. Laser interference was used to measure film thickness during condensation onto a transparent cold window attached to the tail section of a closed-cycle helium cryostat. Optical constants, real (n) and imaginary (k) refractive indices, were determined using Kramers-Kronig analysis. Our calculation reproduces the complete spectrum, including all interference effects.
Keywords
spectroscopy, transmission spectra, infrared spectra, optical constants spectra, data analysis, band position, band width, temperature, mid-IR, far-IR, amorphous, crystalline, molecular solid, nitrile, HCN, C2N2, CH3CN, CH3CH2CN, HC3N, hydrogen cyanide, cyanogen, acetonitrile, propionitrile, cyanoacetylene, Titan
Content
spectral data, phase
Year
2010
Journal
Astrophysical Journal, Supplement Series
Volume
191
Number
1
Pages
96 - 112
Pages number
17
Document type
article
Publication state
published
Doi
10.1088/0067-0049/191/1/96
Identifiers