Collisional efficiencies for vibrational energy relaxation of C[sub 6]F[sub 14] and C[sub 8]F[sub 18]: Dependence on deactivator mass

Journal Article · Thu Jul 15 04:00:00 EDT 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465361· OSTI ID:6396018

Tardy, D C ^[1]

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1. Department of Chemistry, The University of Iowa, Iowa City, Iowa 52242 (United States)

Rate coefficients, [ital k][sub VT], for the deactivation of vibrationally excited C[sub 6]F[sub 14] and C[sub 8]F[sub 18] with average excitation energies ranging from 5000 to 30 000 cm[sup [minus]1] were measured via time resolved optoacoustics for a series of 13 deactivators. Relative collision efficiencies ([beta]=[ital k][sub VT]/[ital k][sub HS]=[l angle][l angle][Delta][ital E][r angle][r angle]/[l angle][ital E][r angle]), an intrinsic measure of the deactivator, were calculated. The average energy removed per collision, [l angle][l angle][Delta][ital E][r angle][r angle], was linear with [l angle][ital E][r angle] since [beta] was found to be independent of energy for all deactivator-substrate combinations. The trends for the deactivators with the 6 and 8 carbon atom substrates were similar except that [beta] was [similar to]15% smaller for the larger substrate. The efficiency for the rare gases increases from helium to neon to argon and then decreases to krypton followed by a slight leveling off for xenon. This trend with deactivator mass was also observed for the polyatomic deactivators studied. The rapid rise and slow fall in [beta] vs mass can be simulated by an encounter between the deactivator and a diatomic substrate containing a pseudo atom with a mass of [similar to]30 amu.

• DOE Contract Number: FG02-87ER13700
• OSTI ID: 6396018
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:2; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ARGON
CARBON COMPOUNDS
CARBON FLUORIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COLLISIONS
ELEMENTS
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
HELIUM
KINETICS
KRYPTON
MASS
MOLECULE COLLISIONS
MOLECULE-MOLECULE COLLISIONS
NEON
NONMETALS
RARE GASES
REACTION KINETICS
RELAXATION
RESOLUTION
SIMULATION
SUBSTRATES
TIME RESOLUTION
TIMING PROPERTIES
VIBRATIONAL STATES
XENON