Rate constants at 297/sup 0/K for proton-transfer reactions with HCN and CH/sub 3/CN. Comparisons with classical theories and exothermicity. [297/sup 0/K; fast ion-molecule reactions]

Journal Article · Thu Dec 16 04:00:00 EST 1976 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100567a019· OSTI ID:7317573

Mackay, G I; Betowski, L D; Payzant, J D; Schiff, H I; Bohme, D K

Rate constants for proton-transfer reactions of the type XH/sup +/ + HCN(CH/sub 3/CN) ..-->.. H/sub 2/CN/sup +/(CH/sub 3/CNH/sup +/) + X where X = H/sub 2/, N/sub 2/, CO, H/sub 2/O, and CO/sub 2/ and of the type HCN(CH/sub 3/CN) + X/sup -/ ..-->.. CN/sup -/(CH/sub 2/CN/sup -/) + XH where X = H, D, OH, SH, NH/sub 2/, C/sub 2/H, and CH/sub 3/O have been measured at 297 +- 2K using the flowing afterglow technique. These reactions for which the measured rate constants span a range from 0.15 to 1.5 X 10/sup -8/cm/sup 3/ molecule/sup -1/s/sup -1/ represent some of the fastest ion-molecule reactions observed to date. The rate constants are compared with the predictions of Langevin, average-dipole-orientation and locked-dipole theories of ion-molecule collisions. The average-dipole-orientation theory provides the most realistic collision rates for these reactions although these appear to be underestimated by approx.10 to approx.40%. The observed dependence of the efficiency for proton transfer on exothermicity indicates that the assumption of unit reaction probability resident in such comparisons may break down at low exothermicities.

• Research Organization: York Univ., Downsview, Ontario
• OSTI ID: 7317573
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 80:26; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
640304 -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
AMMONIA
ANIONS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
COLLISIONS
CRYOGENIC FLUIDS
DEUTERIUM
DIPOLES
ELECTRONEGATIVITY
ELEMENTS
ENTHALPY
FLUIDS
HYDRIDES
HYDROCYANIC ACID
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROGEN SULFIDES
HYDROXIDES
INORGANIC ACIDS
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MEDIUM TEMPERATURE
MOLECULE COLLISIONS
MULTIPOLES
NITRILES
NITROGEN
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION HEAT
REACTION KINETICS
STABLE ISOTOPES
SULFIDES
SULFUR COMPOUNDS
THERMODYNAMIC PROPERTIES
WATER