title: Optical properties of poly-HCN and their astronomical applications.
abstract: Matthews (1992) has proposed that HCN "polymer" is ubiquitous in the solar system. We apply vacuum deposition and spectroscopic techniques previously used on synthetic organic heteropolymers (tholins), kerogens, and meteoritic organic residues to the measurement of the optical constants of poly-HCN in the wavelength range 0.05-40 micrometers. These measurements allow quantitative comparison with spectrophotometry of organic-rich bodies in the outer solar system. In a specific test of Matthews' hypothesis, poly-HCN fails to match the optical constants of the haze of the Saturnian moon, Titan, in the visible and near-infrared derived from astronomical observations and standard models of the Titan atmosphere. In contrast, a tholin produced from a simulated Titan atmosphere matches within the probable errors. Poly-HCN is much more N-rich than Titan tholin.
authors.affiliation: Laboratory for Planetary Studies, Cornell University, Ithaca, NY 14853, USA.
authors.forename: B N
authors.initials: BN
authors.lastname: Khare
authors.forename: C
authors.initials: C
authors.lastname: Sagan
authors.forename: W R
authors.initials: WR
authors.lastname: Thompson
authors.forename: E T
authors.initials: ET
authors.lastname: Arakawa
authors.forename: C
authors.initials: C
authors.lastname: Meisse
authors.forename: P S
authors.initials: PS
authors.lastname: Tuminello
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D019281:Dimerization; D006856:Hydrogen Cyanide / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D055095:Optics and Photonics; D010782:Photolysis; D011108:Polymers / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D012031:Refractometry; D018539:Saturn; D012542:Scattering, Radiation; D016082:Solar System; D013055:Spectrophotometry, Infrared; D014618:Vacuum
chemical_list: D011108:Polymers; D006856:Hydrogen Cyanide