Carbon-13 vapor pressure isotope effect in CHF/sub 3/

Journal Article · Sat Apr 01 04:00:00 EST 1978 · J. Chem. Phys.; (United States)

OSTI ID:5120260

Borodinsky, L; Wieck, H J; Mayfield, D; Ishida, T

The vapor pressure difference between /sup 12/CHF/sub 3/ and /sup 13/CHF/sub 3/ has been measured by means of a cryogenic distillation under total reflux at 11 temperatures between 161.2 and 204.6 /sup 0/K. A second-order extension of Cohen's column kinetics has been tested. The reduced partition function ratio obtained from the distillation data has led to a plot of T ln(f/sub c//f/sub g/) vs 1/T, which displays a steep negative slope and points to a crossover at a temperature above those of the present experiment. The steep negative slope is due to strong external--internal interactions in liquid fluoroform, and the predicted crossover is a consequence of a blue shift in the C--H stretching frequency upon condensation of fluoroform.

• Research Organization: Department of Chemistry, The City University of New York, Brooklyn College, Brooklyn, New York 11210
• OSTI ID: 5120260
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 68:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
CARBON 13
CARBON ISOTOPES
EVEN-ODD NUCLEI
FLUORINATED ALIPHATIC HYDROCARBONS
FLUOROFORM
FUNCTIONS
HALOGENATED ALIPHATIC HYDROCARBONS
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
NUCLEI
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PARTITION FUNCTIONS
PHYSICAL PROPERTIES
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
VAPOR PRESSURE