Spectral separation of gaseous fluorocarbon mixtures and measurement of diffusion constants by 19F gas phase DOSY NMR.
Diffusion-ordered (DOSY) NMR techniques have for the first time been applied to the spectral separation of mixtures of fluorinated gases by diffusion rates. A mixture of linear perfluoroalkanes from methane to hexane was readily separated at 25 degrees C in an ordinary experimental setup with standard DOSY pulse sequences. Partial separation of variously fluorinated ethanes was also achieved. The constants of self-diffusion of a set of pure perfluoroalkanes were obtained at pressures from 0.25 to 1.34 atm and temperatures from 20 to 122 degrees C. Under all conditions there was agreement within 20% of experimental self-diffusion constant D and values calculated by the semiempirical Fuller method.
Marchione
Alexander A
AA
DuPont Central Research and Development, Experimental Station, Wilmington, DE 19803, USA. alexander.a.marchione@usa.dupont.com
McCord
Elizabeth F
EF
D000465:Algorithms; D004058:Diffusion; D005461:Fluorine / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy
D005466:Fluorocarbons; D005740:Gases; D007554:Isotopes; D005461:Fluorine