The effect of site-specific isotopic substitutions on transport coefficients of liquid methanol
A new approach is suggested for studying the nature of molecular transport in simple liquids, which makes use of site-specific isotopic substitutions. Its application represents the first systematic experimental study of a theoretically predicted correlation between transport coefficients in liquids and molecular moments of inertia. For this purpose, we have determined the viscosities and self-diffusion coefficients at 25 /degree/C of normal methanol and seven isotopically labeled methanol species: CH/sub 3/OD, CD/sub 3/OH, CD/sub 3/OD, CH/sub 2/DOH, CHD/sub 2/OH, CHD/sub 2/OD, and /sup 13/CH/sub 3/OH. Except for /sup 12/C//sup 13/C substitution, the observed isotope effects are significantly larger than predicted by a square root of mass dependence, but are well correlated with the square roots of the moments of inertia. The results give strong evidence that translation--rotation coupling influences the transport processes in methanol, thus confirming earlier interpretations of isotope effects upon the transport in water.
- Research Organization:
- Institut f ur Physikalische Chemie und Elektrochemie der Universitat, Kaiserstr. 12, D-7500 Karlsruhe, Federal Republic of Germany(DE); Dipartimento di Chimica, Universita degli Studi Bari, Via Amendola 173, I-70 126, Bari, Italy
- OSTI ID:
- 6007388
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 91:4; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
ALCOHOLS
CARBON 13
CARBON ISOTOPES
DEUTERIUM
DIFFUSION
EVEN-ODD NUCLEI
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
METHANOL
MOMENT OF INERTIA
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
SELF-DIFFUSION
STABLE ISOTOPES
VISCOSITY